tag:blogger.com,1999:blog-18405195118210462312024-03-19T14:33:56.586+11:00Levy Sound DesignElectronics / Audio / MachiningMichael Levyhttp://www.blogger.com/profile/18217504205268410755noreply@blogger.comBlogger34125tag:blogger.com,1999:blog-1840519511821046231.post-81612089339656738032021-01-13T18:56:00.017+11:002021-07-04T20:38:47.185+10:00Digital Readout (DRO) for mini lathe using cheap digital calipers<p></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjNtUcX5jgQT1c5lWKoAgiDhKd6-ZX-ZN4uPsWsXuGbHZ0o7jcOgZWoLqFRWK5tqijm1HFHRsjSqvvD84q-P_0hyphenhyphent1Tlk-bPOMyo0Jz5T3cxIXt8AHi3CdbOiohHGiqELbXru0pZ1qpQ8fu/s2048/minilathe_DROattached.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1556" data-original-width="2048" height="304" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjNtUcX5jgQT1c5lWKoAgiDhKd6-ZX-ZN4uPsWsXuGbHZ0o7jcOgZWoLqFRWK5tqijm1HFHRsjSqvvD84q-P_0hyphenhyphent1Tlk-bPOMyo0Jz5T3cxIXt8AHi3CdbOiohHGiqELbXru0pZ1qpQ8fu/w400-h304/minilathe_DROattached.jpg" width="400" /></a></div><span style="font-family: arial;"><p>Digital calipers can be used as an inexpensive alternative to a commercially available DRO for home workshop machine tools.</p><p>Many hobbyists attach the calipers to the axis of their machines, and use the screen and buttons directly on the calipers as a DRO. This has several disadvantages:</p><p></p><ul style="text-align: left;"><li>Calipers are not shielded from cutting fluids and chips</li><li>While you can zero the caliper, there is no way to set the position to a value.</li><li>For a lathe, the X-axis dimension will be a radius, not a diameter.</li></ul><p></p><p>The PCB of commonly available digital calipers has traces for serial data output which can be read by a microcontroller. Use of a microcontrolled enables the connection of a display, and calculation of relative position from a user input entered by way of a keypad.</p><p>Example: Use of DRO with lathe turning operation<br /></p><ol><li>Round stock is placed in the lathe chuck.</li><li>Stock is faced, and the Z-axis is zeroed.</li><li>Stock is turned lightly to remove any eccentricity, and the diameter is measured. This X-axis diameter is entered into the DRO using the keypad.</li><li>The part can then be turned to the correct length as displayed by the DRO Z value, and to the correct diameter as displayed by the DRO X value.</li></ol><p>In this project, I have connected two sets of digital calipers to an Arduino Nano board to display the X (cross slide) axis diameter and Z (carriage) axis position of my 7x14 mini lathe. The DRO is accurate to 0.01mm in the Z-axis, and 0.02mm in the X-axis diameter (this is because the cut of the diameter is 2 x the travel of the caliper scale).</p></span><span style="font-family: arial;"><p>I have also written code and included connections in the schematic for a 3 axis version for a milling machine.</p></span><div><span style="font-family: arial;"><p><b>Modification of calipers</b></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiYcXEl7QnggEdidpGJQhXeUCcE0IKeEyGcNyrjlqwLL0tpYCUl19_S5xa6BGiFm4N40egOXO7QRqoAKX9LEjHQR5DI2PG26WsHwPEDDJJRAWP8zOBd3K1s9Wle7S4_GUoWx-05-sQGul4l/s2048/caliperModification1.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" data-original-height="1536" data-original-width="2048" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiYcXEl7QnggEdidpGJQhXeUCcE0IKeEyGcNyrjlqwLL0tpYCUl19_S5xa6BGiFm4N40egOXO7QRqoAKX9LEjHQR5DI2PG26WsHwPEDDJJRAWP8zOBd3K1s9Wle7S4_GUoWx-05-sQGul4l/s320/caliperModification1.jpg" width="320" /></a></div>Calipers were disassembled, and connections soldered for the serial line.</span></div><div><span style="font-family: arial;">I used CAT5 cable as it was what I had available.<br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjjJdgOCt7fiBQX_WepqSKBGbLUqLbbxYz6F-17MLdcj7avoUzeZqRuC_SQ36R89fOocKIYqnnRqU3ab9hhtgpDbe2l2sLVsuKiLJ2Xd-zCdtipZ7tjdejPeWSc1J6wHGYVUiP1ae-cYVPi/s2048/caliperModification2.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" data-original-height="1536" data-original-width="2048" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjjJdgOCt7fiBQX_WepqSKBGbLUqLbbxYz6F-17MLdcj7avoUzeZqRuC_SQ36R89fOocKIYqnnRqU3ab9hhtgpDbe2l2sLVsuKiLJ2Xd-zCdtipZ7tjdejPeWSc1J6wHGYVUiP1ae-cYVPi/s320/caliperModification2.jpg" width="320" /></a></div>Cable secured to case of calipers.<br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhxKtgbWn2RtlfRm74dbCKU4Ym4J3kwtuz59T6LArb0hW28b9Zirh3ZKh-4FtgqYsGufPHU9Qr90EPX04Ha6NFQi9i3aBPTzlfozBeoyNGalXDkc4RpNC0P2rRGHlXutZ6gpqehYuBEOzeP/s2048/caliperModification3.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" data-original-height="1536" data-original-width="2048" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhxKtgbWn2RtlfRm74dbCKU4Ym4J3kwtuz59T6LArb0hW28b9Zirh3ZKh-4FtgqYsGufPHU9Qr90EPX04Ha6NFQi9i3aBPTzlfozBeoyNGalXDkc4RpNC0P2rRGHlXutZ6gpqehYuBEOzeP/s320/caliperModification3.jpg" width="320" /></a></div></span></div><div><div><span style="font-family: arial;">The jaws were cut to size with an angle grinder, and slots cut </span><span style="font-family: arial;">for M4 screws to fix the calipers to the mini lathe. </span><span style="font-family: arial;">Caliper jaws are made of hard steel, so drilling is not advisable. Slots </span><span style="font-family: arial;">also allow for some adjustment.</span></div><div><span style="font-family: arial;"><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhLksoJdWG8i_ZUUWHNuy6xnyzKlaTGXA975GS_MJKlbzT3kfMm-xAupOrsRrklsH7F-6qARuJC0Df-BAaPKQe9Cg8q8NULGgagCiovjdx9U2VanRxI4gDBLqzKUbhBuHTiTHJPwx-4yoUN/s2048/caliperModification4.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" data-original-height="1536" data-original-width="2048" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhLksoJdWG8i_ZUUWHNuy6xnyzKlaTGXA975GS_MJKlbzT3kfMm-xAupOrsRrklsH7F-6qARuJC0Df-BAaPKQe9Cg8q8NULGgagCiovjdx9U2VanRxI4gDBLqzKUbhBuHTiTHJPwx-4yoUN/s320/caliperModification4.jpg" width="320" /></a></div>Modified calipers were reassembled and tested.<br /><p><br /></p><p><br /></p><p><br /></p><p><br /></p><p><br /></p><p><br /></p><p><br /></p><p><br /></p><div><b>Schematic</b></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEha1YZgGcMeUzNlV-6UNqLhZNviFuMWuh4njx3L1EKiGVRulIX2bEfEDbxVhRYG5rec4uMyvZXAIL0bwBmUEtWkSpI05aLPlLTK7yfQwfrI20xSRy27YTGFo-Bvz5wrFcSdl8xtjFxcrvg9/s1545/DRO_eagle_schematic.png" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" data-original-height="1065" data-original-width="1545" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEha1YZgGcMeUzNlV-6UNqLhZNviFuMWuh4njx3L1EKiGVRulIX2bEfEDbxVhRYG5rec4uMyvZXAIL0bwBmUEtWkSpI05aLPlLTK7yfQwfrI20xSRy27YTGFo-Bvz5wrFcSdl8xtjFxcrvg9/s320/DRO_eagle_schematic.png" style="cursor: move;" width="320" /></a></div><p>Calipers are ordinarily powered from a 1.5V battery. A circuit was designed to supply the calipers with 1.5V, and to convert the serial line to the 5V logic level required by the Arduino nano microcontroller.</p><div>An I2C display is used for the screen, and a matrix keypad for user input.</div><div><br /></div><div><br /></div><div><div><br /></div><p></p><p><br /></p></div><p><br /></p><p><br /></p><p><b>PCB design</b></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjfTKAllfl2foTph-FvvGs89m101pxW5Kj44Roa64G_kLw-77X-4WzFnU9hsAejpJ_wdNx6TMTHSZW8RcJCMF35kxTmzCPFUphu2DYMI44fphPP1vlhgXJA1u8ebbbt8JOSDkN3Q_vTnP9b/s909/DRO_eagle_pcbLayout.png" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" data-original-height="542" data-original-width="909" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjfTKAllfl2foTph-FvvGs89m101pxW5Kj44Roa64G_kLw-77X-4WzFnU9hsAejpJ_wdNx6TMTHSZW8RcJCMF35kxTmzCPFUphu2DYMI44fphPP1vlhgXJA1u8ebbbt8JOSDkN3Q_vTnP9b/s320/DRO_eagle_pcbLayout.png" width="320" /></a></div><br /><p>The PCB was drawn to the dimensions of the lid of an off the shelf plastic enclosure, and all through hole components were hidden behind the keypad.</p><p><br /></p><p><br /></p><p><br /></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi2R4fkp0EyTqoP2MvZYjRvA0c1UEknUSUqbzcjQ4cJLoqE61E2xNUqhVnfy7slFajSEMhZy0hUb3zaoum6teGFEe4pqVQdjv4TNkD_c7-4KuVjc5cBGnofTEeq3f2sineNLXuZj_6nSSJp/s2048/DRO_panel.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" data-original-height="1542" data-original-width="2048" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi2R4fkp0EyTqoP2MvZYjRvA0c1UEknUSUqbzcjQ4cJLoqE61E2xNUqhVnfy7slFajSEMhZy0hUb3zaoum6teGFEe4pqVQdjv4TNkD_c7-4KuVjc5cBGnofTEeq3f2sineNLXuZj_6nSSJp/s320/DRO_panel.jpg" width="320" /></a></div><br /><p><br /></p><p>The PCB was printed by JLC PCB.<br />Components were soldered in place.<br />The PCB mounts nicely to the enclosure.</p><p>I have as yet neglected to print a sticker for the keypad.</p><p><br /></p><p><br /></p><p><br /></p><p><br /></p><p><b>User interface</b></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiXjKXVPEPQsdlDbdzSnC44-4Gtt1LhsnkADxL0Lv-_-YfF4vCa0MUFNLM_jmNybw46wbmClzCY6KUCtKflJfHiaSjn8F88XR7-ASBTuQE0ay-5JfhC0bN9kuyM7vxeCjZmIr-pslpTTA8o/s2048/DRO_userInterface_2axis.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" data-original-height="1343" data-original-width="2048" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiXjKXVPEPQsdlDbdzSnC44-4Gtt1LhsnkADxL0Lv-_-YfF4vCa0MUFNLM_jmNybw46wbmClzCY6KUCtKflJfHiaSjn8F88XR7-ASBTuQE0ay-5JfhC0bN9kuyM7vxeCjZmIr-pslpTTA8o/s320/DRO_userInterface_2axis.jpg" width="320" /></a></div><br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjZTdfellVJHVhv4XKYOpiDElFz4Die69N-lNkXy5Z8sBIJr8l0DX1dhFhMnfTUPi3JhIGNsgtop1cJorqR6sFVHWTmuRYzUmU-VUVLloMmvUyDhl35Oq_WQ7u6xOXhUgBOAmG26Kfm4-kp/s2048/DRO_userInterface_3axis.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" data-original-height="1343" data-original-width="2048" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjZTdfellVJHVhv4XKYOpiDElFz4Die69N-lNkXy5Z8sBIJr8l0DX1dhFhMnfTUPi3JhIGNsgtop1cJorqR6sFVHWTmuRYzUmU-VUVLloMmvUyDhl35Oq_WQ7u6xOXhUgBOAmG26Kfm4-kp/s320/DRO_userInterface_3axis.jpg" width="320" /></a></div><br /><p><br /></p><p><br /></p><p><br /></p><p><br /></p><p><br /></p><p><br /></p><p><br /></p><p><b>Mounting calipers to the mini lathe</b></p><br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiuADVxs5TNGOAkq0pfL-yfdgjhWpgpfimXeWrfm-Yb2scWnrskZpD1hQSlPLkg2SFw1O3krzKpKtrT6xe6KDq0GE_yG_KRnAeQJymsK9qASBsr0Cr-MnHCYEH3LYHuWHWS8U8CEWMveuAv/s2048/Xaxis_noShield.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" data-original-height="1536" data-original-width="2048" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiuADVxs5TNGOAkq0pfL-yfdgjhWpgpfimXeWrfm-Yb2scWnrskZpD1hQSlPLkg2SFw1O3krzKpKtrT6xe6KDq0GE_yG_KRnAeQJymsK9qASBsr0Cr-MnHCYEH3LYHuWHWS8U8CEWMveuAv/s320/Xaxis_noShield.jpg" width="320" /></a></div>Holes were drilled and tapped in cross slide for M4 screws to mount the X-axis caliper.<br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg6jW0xp2An_zIsE6cNQnNDNxj3VqUWcBa6QkzFz08TSNtbV96Pe50A-gKeaAJgiu7gWux9tT-GORGgUY-ONrsJf8oE1P_Ka1_lrO_nfTuNVBqbRl-rqmG6H7kNhdh0H01cBDj4zAqqFzFn/s2048/Xaxis_shieldFab.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" data-original-height="2048" data-original-width="1536" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg6jW0xp2An_zIsE6cNQnNDNxj3VqUWcBa6QkzFz08TSNtbV96Pe50A-gKeaAJgiu7gWux9tT-GORGgUY-ONrsJf8oE1P_Ka1_lrO_nfTuNVBqbRl-rqmG6H7kNhdh0H01cBDj4zAqqFzFn/s320/Xaxis_shieldFab.jpg" /></a></div></span></div><div><span style="font-family: arial;">An M4 nut was soldered to the sheet metal chip shield to form an integral bracket.<br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh8XVCDJCFPS97JHpe7vL7s-SNSwFNTwjG5jKN0lG386ZakE_LN2i1MIQIlYPk3ZVUQVfyrbgiMf01Kn9qnzsWUT3Zbx_beW9jrcRaJqp4jyseY-RJDYc3f7o8l3xHvHUEHSAtQu1I7eUlK/s2048/Xaxis_shield.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" data-original-height="1558" data-original-width="2048" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh8XVCDJCFPS97JHpe7vL7s-SNSwFNTwjG5jKN0lG386ZakE_LN2i1MIQIlYPk3ZVUQVfyrbgiMf01Kn9qnzsWUT3Zbx_beW9jrcRaJqp4jyseY-RJDYc3f7o8l3xHvHUEHSAtQu1I7eUlK/s320/Xaxis_shield.jpg" width="320" /></a></div>Chip shield installed and X-axis caliper mounted.<br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhlSLomjMXktgyyfEhzLLplOyIJV8qCvmiaL0yHoYPsbRbSMvKZLJv85Psrb5Y_Lu1Myb6LSorbwniTvE2TPy60mcXtc1CDPw07XUBA9HsttoD41kYchqUwDNOU0vGxhjUUP77zr0CFA07P/s2048/Zaxis_noShield.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" data-original-height="1539" data-original-width="2048" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhlSLomjMXktgyyfEhzLLplOyIJV8qCvmiaL0yHoYPsbRbSMvKZLJv85Psrb5Y_Lu1Myb6LSorbwniTvE2TPy60mcXtc1CDPw07XUBA9HsttoD41kYchqUwDNOU0vGxhjUUP77zr0CFA07P/s320/Zaxis_noShield.jpg" width="320" /></a></div>A small aluminium clamp was milled to fix the Z-axis calipers to the lathe bed ways. The clamp allows you to adjust position of the bracket, as the calipers only permit ~140mm of travel.<p><br /></p><p><br /></p><p><br /></p><p><br /></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi3eUlw5DjEcO2lsVnPrfSmCk_5TFNrYhlO1Pregy263Zv492xKv6iy9vatFWeptkc_b8i1v7Ia-1f8YDcCHjkgvXPPQKPdXttHgE9pWgoUqytgE7H1OXbG4r3JQjsnRqdU_6F8ltXvnNSM/s2048/Zaxis_shield.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" data-original-height="1554" data-original-width="2048" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi3eUlw5DjEcO2lsVnPrfSmCk_5TFNrYhlO1Pregy263Zv492xKv6iy9vatFWeptkc_b8i1v7Ia-1f8YDcCHjkgvXPPQKPdXttHgE9pWgoUqytgE7H1OXbG4r3JQjsnRqdU_6F8ltXvnNSM/s320/Zaxis_shield.jpg" width="320" /></a></div><br /><p>Chip shield installed over Z-axis calipers.</p><p><br /></p><p><br /></p><p><br /></p><p><br /></p><p><br /></p><p><br /></p><p><br /></p><p><b>DRO mount</b></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh5Ep34zuv1_lMSB7xxo2fPNEsUgS-rMGzYpgPHa26-J3bLFJaCuqEsFGE5EHfLmGlaUJs80TQl6aeVlMawgfXkbCgKfN0dUyu_jkIPpvldVVKVZwUv9ypAXT-aJ8Z4js00TZxwa9DvTzpN/s2048/DRO_mount.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" data-original-height="2048" data-original-width="1536" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh5Ep34zuv1_lMSB7xxo2fPNEsUgS-rMGzYpgPHa26-J3bLFJaCuqEsFGE5EHfLmGlaUJs80TQl6aeVlMawgfXkbCgKfN0dUyu_jkIPpvldVVKVZwUv9ypAXT-aJ8Z4js00TZxwa9DvTzpN/s320/DRO_mount.jpg" /></a></div><br /><p>The DRO is attached to the mini lathe using a cheap "magic arm" camera mount for easy adjustment.</p><p>The plastic packaging that the enclosure was sold in protects the DRO from cutting fluid and chips.</p><p><br /></p><p><br /></p><p><br /></p><p><br /></p><p><br /></p><p><br /></p><p><br /></p><p><br /></p><p><b>Project Files</b></p><p><a href="https://github.com/bigredlevy/Digital-Caliper-DRO">https://github.com/bigredlevy/Digital-Caliper-DRO </a></p><p><br /></p><p><br /></p></span><p></p></div></div>Michael Levyhttp://www.blogger.com/profile/18217504205268410755noreply@blogger.comtag:blogger.com,1999:blog-1840519511821046231.post-82285248459850075552020-06-19T17:35:00.007+10:002021-08-19T08:10:58.490+10:00DC Motor Controller Circuit using Triac Dimmer<div style="margin: 0px;">
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<span style="font-family: "arial";">This circuit has been designed for use with 200VDC motors, such as those found in treadmills.</span></div>
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<span style="font-family: "arial";">It uses a cheap triac motor controller, which can be found on eBay listed as 2000W SCR Motor Controller.</span></div>
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<span style="font-family: "arial";"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi4hyphenhyphenLR2M_rWpwTHUUOLNvE0X9sE1K9OofL8hV_BDSpI0cmpbE0oAvGAOZxCynFQKqzwPv-OfYeD7rEbByMxku7u18AToTrDhRmSEde4YDwXwwcfHF8NfH9hHxOndaNEKXPNtqBmX-A0-C4/s1002/2000W+SCR+Motor+Controller.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" data-original-height="1002" data-original-width="1002" height="256" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi4hyphenhyphenLR2M_rWpwTHUUOLNvE0X9sE1K9OofL8hV_BDSpI0cmpbE0oAvGAOZxCynFQKqzwPv-OfYeD7rEbByMxku7u18AToTrDhRmSEde4YDwXwwcfHF8NfH9hHxOndaNEKXPNtqBmX-A0-C4/w256-h256/2000W+SCR+Motor+Controller.jpg" width="256" /></a></span></div>
<div style="margin: 0px;"><span style="font-family: arial;">With an input of 240V AC, the maximum rectified output of the SCR controller will be 340V DC peak. The circuit was modified for use with 200V DC treadmill motors. This simply required replacing one resistor on the PCB (see schematic).</span></div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhzUBCqScSySvI6yQJGNuwOUhTkDNATgVm9YDQvq0bRSq_2IZzWxdbupzXbx5QsCHlg_HqnxXez5hAWUGo1VJ14kVscTPBQhPQvi9WFhvSVaIdJJOUEHtGHSrfd5fV7I9lrr4h0RQGB4Isf/s4160/IMG20200522141940.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><span style="font-family: "arial";"><img border="0" data-original-height="3120" data-original-width="4160" height="192" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhzUBCqScSySvI6yQJGNuwOUhTkDNATgVm9YDQvq0bRSq_2IZzWxdbupzXbx5QsCHlg_HqnxXez5hAWUGo1VJ14kVscTPBQhPQvi9WFhvSVaIdJJOUEHtGHSrfd5fV7I9lrr4h0RQGB4Isf/w256-h192/IMG20200522141940.jpg" width="256" /></span></a></div>
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<span style="font-family: "arial";">The circuit fits in a small metal enclosure.</span></div>
Michael Levyhttp://www.blogger.com/profile/18217504205268410755noreply@blogger.comtag:blogger.com,1999:blog-1840519511821046231.post-33594944443157207352020-06-19T12:45:00.011+10:002021-01-13T21:40:43.974+11:00Homemade Milling Machine<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEit8fNJPY3203dQ53JzDlZQZ3ApJhpu4dG3sVFkSV0Gi3nf3TBCZQADbxItPhK2GfMCCa6JaIpeiZt0VF3yZ3d8PfB-aIjvK0BwV0OeFVi6xvBoq5Yp08NKt0SJpDYtxKiB4X4YwUeHALkr/s4160/IMG20200619092147.jpg" style="margin-left: 1em; margin-right: 1em;"><font face="arial"><img border="0" data-original-height="4160" data-original-width="3120" height="500" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEit8fNJPY3203dQ53JzDlZQZ3ApJhpu4dG3sVFkSV0Gi3nf3TBCZQADbxItPhK2GfMCCa6JaIpeiZt0VF3yZ3d8PfB-aIjvK0BwV0OeFVi6xvBoq5Yp08NKt0SJpDYtxKiB4X4YwUeHALkr/w375-h500/IMG20200619092147.jpg" width="375" /></font></a></div><div><font face="arial"><br /></font></div><font face="arial">This milling machine is the result of years of tinkering in the home workshop, and is built mostly from scrap materials at low cost.</font><div><font face="arial"><br /></font></div><div><font face="arial">This project started as a lathe, but after encountering significant difficulty in the construction of the project, I decided to <a href="http://levysounddesign.blogspot.com/2020/06/mini-lathe.html">purchase a mini lathe instead</a>. The project was then repurposed to a milling machine.</font></div><div><font face="arial"><br /></font></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgy8W09jQ3fxhad24bf-MHHUVPHCBzg9RPjFx3FusUoFUlBgduQcg8yUNJb2ozz4pOWIr92nc7mc1mBDlO3TJ7xR8bMQu6d4PtAUVM6cwNpbBzemnU_pMX8e0kU3cS7MxQigj_LkKG4hyphenhyphenPP/s4160/IMG20200619092203.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><font face="arial"><img border="0" data-original-height="3120" data-original-width="4160" height="192" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgy8W09jQ3fxhad24bf-MHHUVPHCBzg9RPjFx3FusUoFUlBgduQcg8yUNJb2ozz4pOWIr92nc7mc1mBDlO3TJ7xR8bMQu6d4PtAUVM6cwNpbBzemnU_pMX8e0kU3cS7MxQigj_LkKG4hyphenhyphenPP/w256-h192/IMG20200619092203.jpg" width="256" /></font></a></div><div><font face="arial">X-axis travel is 120mm, Y-axis travel is 60mm, with ample Z-axis travel.</font></div><div><font face="arial"><br /></font></div><div><font face="arial"><br /></font></div><div><font face="arial"><br /></font></div><div><font face="arial"><br /></font></div><div><font face="arial"><br /></font></div><div><font face="arial"><br /></font></div><div><font face="arial"><br /></font></div><div><font face="arial"><br /></font></div><div><font face="arial"><br /></font></div><div><font face="arial"><br /></font></div><div><font face="arial"><br /></font></div><div><font face="arial"><br /></font></div><div><font face="arial"><b>Construction</b></font></div><div><font face="arial"><b><br /></b></font></div><div><font face="arial"><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgkw520GmjpBsYEBp4Cqlnl_1zzLHMxAXGW5-Gc6UtoQO55khVhUw1eDwa7ZjH4rNQ2mcUwfK2zjHpgEyhEwkd-K91UU9MUzNBGEXfeM-ZSxCxqk-JK8clwJZPQqbWse1C86X5DBPOJUoBW/s4160/IMG20200507113754.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" data-original-height="4160" data-original-width="3120" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgkw520GmjpBsYEBp4Cqlnl_1zzLHMxAXGW5-Gc6UtoQO55khVhUw1eDwa7ZjH4rNQ2mcUwfK2zjHpgEyhEwkd-K91UU9MUzNBGEXfeM-ZSxCxqk-JK8clwJZPQqbWse1C86X5DBPOJUoBW/s320/IMG20200507113754.jpg" /></a></div>The headstock is 90x90 thick wall square section.</font></div><div><font face="arial">The 20mm spindle holds MT2 tooling with a drawbar.</font></div><div><font face="arial"><br /></font></div><div><font face="arial">The spindle has a shoulder on the bottom end, and is threaded at the top to accept a brass nut, which presses against the pully and two turned aluminium spacers in order to pre-load the flange bearings.</font></div><div><font face="arial"><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhwLmEEwFA0tfo1apaBcJ48rZDZEyHK3eOHiGwR0F2VXi9BvdCe6uZkJ8TYZx1RcHf4k-XfpuHbgB6ybqYKGOyY35aOksNKhb-aEY_pg3rLUtuomVSJIkfp7KJPhwX6CzXo_i9hJp1LVMsL/s4160/IMG20200506100435.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" data-original-height="4160" data-original-width="3120" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhwLmEEwFA0tfo1apaBcJ48rZDZEyHK3eOHiGwR0F2VXi9BvdCe6uZkJ8TYZx1RcHf4k-XfpuHbgB6ybqYKGOyY35aOksNKhb-aEY_pg3rLUtuomVSJIkfp7KJPhwX6CzXo_i9hJp1LVMsL/s320/IMG20200506100435.jpg" /></a></div>The Z-axis ways were constructed by welding two pieces of angle iron together, and is mounted to rectangular tubing.</font></div><div><font face="arial">The entire carriage assembly is made from 6mm cold rolled steel.</font></div><div><font face="arial"><br /></font></div><div><font face="arial">A bolt in a tapped hole in the carriage presses against a turned button to lock the Y-axis.</font></div><div><font face="arial"><br /></font></div><div><font face="arial">Pulleys and handwheels were turned from a length of 65mm diameter aluminium purchased from a scrap yard.</font></div><div><font face="arial"><br /></font></div><div><font face="arial">All leadscrews are M6 threaded rod, as the 1mm pitch made dividing the 0.1mm handwheel graduations simple.</font></div><div><font face="arial"><br /></font></div><div><font face="arial">A 10mm nut on each handwheel allows power feed by use of a power drill.</font></div><div><br /></div><div><br /></div><div><font face="arial"><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgGjS1vkQxqfoFUDmh-aUIsEh7EH0cIpBYKN-s_5ZmDqR5M9dkoOnCVcJjJvX5GjHXICKDfzEfojrxdDXpkCV4zwhThoZJS-19iHVHORDAKfJHX2vhbENj0faiyyLtEN_7WQt0oxFpHvpKy/s4160/IMG20200619122101.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" data-original-height="3120" data-original-width="4160" height="192" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgGjS1vkQxqfoFUDmh-aUIsEh7EH0cIpBYKN-s_5ZmDqR5M9dkoOnCVcJjJvX5GjHXICKDfzEfojrxdDXpkCV4zwhThoZJS-19iHVHORDAKfJHX2vhbENj0faiyyLtEN_7WQt0oxFpHvpKy/w256-h192/IMG20200619122101.jpg" width="256" /></a></div>The motor was taken from a scrapped treadmill, and is controlled by a <a href="http://levysounddesign.blogspot.com/2020/06/dc-motor-controller-using-triac-dimmer.html">modified triac based motor controller</a> bought cheaply on eBay. </font></div><div><font face="arial"><br /></font></div><div><font face="arial"><b><br /></b></font></div><div><font face="arial"><b><br /></b></font></div><div><font face="arial"><b><br /></b></font></div><div><font face="arial"><b><br /></b></font></div><div><font face="arial"><b><br /></b></font></div><div><font face="arial"><b><br /></b></font></div><div><font face="arial"><b><br /></b></font></div><div><br /></div><div><br /></div><div><br /></div><div><font face="arial"><b>Tooling</b></font></div><div><font face="arial"><b><br /></b></font></div><div><font face="arial"><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgLbbM5JeJAWT_wAHCXdMGFCX3TEe1LOBmj6LNlzqJBOy71ji9GWOuob2rt4WMWTkNOPN7Tiizc0G6gpqhXAz5g9aoN2yIuIyPfs3OHZiFPZFywnKVgeGWCeqG2jjwqg_iWqVv8THLfLeVT/s4160/IMG20200515124357.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" data-original-height="3120" data-original-width="4160" height="192" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgLbbM5JeJAWT_wAHCXdMGFCX3TEe1LOBmj6LNlzqJBOy71ji9GWOuob2rt4WMWTkNOPN7Tiizc0G6gpqhXAz5g9aoN2yIuIyPfs3OHZiFPZFywnKVgeGWCeqG2jjwqg_iWqVv8THLfLeVT/w256-h192/IMG20200515124357.jpg" width="256" /></a></div>MT2 tool holder for 6mm HSS end mill.</font></div><div><font face="arial">Made from a spare Jacobs taper adapter. </font></div><div><font face="arial">Bored and tapped for M6 drawbar.</font></div><div><font face="arial"><br /></font></div><div><font face="arial"><br /></font></div><div><font face="arial"><br /></font></div><div><font face="arial"><br /></font></div><div><font face="arial"><br /></font></div><div><font face="arial"><br /></font></div><div><font face="arial"><br /></font></div><div><font face="arial"><br /></font></div><div><font face="arial"><br /></font></div><div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgSCDTlcuwnBRRZPYetp-dJjMvtoHKv9HTwyaGy9Rl2kCQ2VvYLnIHlYiSZoR_-K4NNbtHvYhBV-Ou4fEAuh8n1BW3cmIipV0ms1JwtK_gjumaDeA66VS1cvElfMCOtxk2kB4W6S7R8ko_W/s4160/IMG20200531171455.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><font face="arial"><img border="0" data-original-height="4160" data-original-width="3120" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgSCDTlcuwnBRRZPYetp-dJjMvtoHKv9HTwyaGy9Rl2kCQ2VvYLnIHlYiSZoR_-K4NNbtHvYhBV-Ou4fEAuh8n1BW3cmIipV0ms1JwtK_gjumaDeA66VS1cvElfMCOtxk2kB4W6S7R8ko_W/s320/IMG20200531171455.jpg" /></font></a></div><font face="arial">MT2 Fly cutter holds lathe tools.</font></div><div><font face="arial">Made from a spare lathe centre.</font></div><div><font face="arial">Bored and tapped for M6 drawbar.</font></div>Michael Levyhttp://www.blogger.com/profile/18217504205268410755noreply@blogger.comtag:blogger.com,1999:blog-1840519511821046231.post-76553266351517999462020-06-19T10:56:00.012+10:002021-07-04T20:39:37.618+10:00Mini Lathe<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiSHrsR208aOqdKByCCTYq88yMZUcm38BCRPvCNaOYfPIP35IuIf0fElI67mQa9D77pRqzJzmkykkjpbjwGFwRJN4oNxbyl4BzXUELj69ECY23Uc9Qg5NKQXfpKlEwQQr_XV8p69dKVrel6/s3359/MiniLathe.jpg" style="margin-left: 1em; margin-right: 1em;"><font face="arial"><img border="0" data-original-height="1208" data-original-width="3359" height="225" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiSHrsR208aOqdKByCCTYq88yMZUcm38BCRPvCNaOYfPIP35IuIf0fElI67mQa9D77pRqzJzmkykkjpbjwGFwRJN4oNxbyl4BzXUELj69ECY23Uc9Qg5NKQXfpKlEwQQr_XV8p69dKVrel6/w625-h225/MiniLathe.jpg" width="625" /></font></a></div><font face="arial"><br /></font><div><font face="arial">A 7x12" mini lathe is an excellent addition to the home workshop. With some patience it can produce parts to a high standard. As with most cheap import tools, the mini lathe will require modification and repair upon purchase.</font></div><div><font face="arial"><br /></font></div><div><b><font face="arial">Initial Modifications</font></b></div><div><font face="arial"><br /></font></div><div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgCIqYjAjZDTGHhlAEz3N3tdN2IOqKE4AlSzCIy7F7NjAB7B94xKPpUQ2M6hFSuw_Ixn42jbtXf0s60VOTJUsPY3IFBQWSZ8v-9ZbnMYozV0sT2fy-4XfaOXi52pIcw__cFkIxftq7gbng3/s4160/IMG20200427085107.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><font face="arial"><img border="0" data-original-height="3120" data-original-width="4160" height="192" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgCIqYjAjZDTGHhlAEz3N3tdN2IOqKE4AlSzCIy7F7NjAB7B94xKPpUQ2M6hFSuw_Ixn42jbtXf0s60VOTJUsPY3IFBQWSZ8v-9ZbnMYozV0sT2fy-4XfaOXi52pIcw__cFkIxftq7gbng3/w256-h192/IMG20200427085107.jpg" width="256" /></font></a></div><font face="arial">Electrical:</font></div><div><font face="arial">Visually inspect the earth connection behind the motor controller housing. Unscrew the terminal from the headstock and remove any paint from the contact area. Reconnect the earth and test with a multimeter. Earth continuity must be less than 1Ω from the chassis to the earth pin of the cord.</font></div><div><span style="font-family: arial;"><br /></span></div><div><font face="arial">Inspect the mains fuse and confirm that it is T4A. A higher value will cause significant damage to the controller board under fault conditions.</font></div><div><font face="arial"><br /></font></div><div><font face="arial">Mechanical:</font></div><div><font face="arial">Take apart carriage, slides and apron, and clean with kerosene to remove grinding dust from the factory.</font></div><div><font face="arial">Deburr all sharp edges, including the bed, carriage assembly, and tool post.</font></div><div><font face="arial">Glue sheet metal over holes in chassis to prevent swarf getting into the motor.</font></div><div><font face="arial">Use short screws to fill tapped holes in carriage, again to prevent swarf ingress.</font></div><div><font face="arial"><br /></font></div><div><font face="arial">After the lathe is full re-assembled, take some time to carefully adjust the gib screws in the cross slide and compound slide.</font></div><div><font face="arial"><br /></font></div><div><font face="arial">Align the tailstock. This can be done quickly by putting a centre in the tailstock and aligning it to a piece of stock in the 3 jaw chuck which has been turned to a point. Having the two points aligned when the tailstock is both the fully extended and fully retracted will ensure that the tailstock is parallel to the lathe bed.</font></div><div><font face="arial">A more accurate test is to turn a piece of stock, </font><span style="font-family: arial;">held between centres and driven by a dog,</span><span style="font-family: arial;"> along the length of the bed. The diameter is measured at each end to determine the tailstock offset.</span></div><div><span style="font-family: arial;"><br /></span></div><div><span style="font-family: arial;"><b>Periodic Maintenance</b></span></div><div><span style="font-family: arial;"><br /></span></div><div><span style="font-family: arial;">Remove the sheet metal motor cover and check that no swarf has entered the motor housing. If chips short against the motor brushes, the control board will fail. </span></div><div><span style="font-family: arial;">Oil the bearing surfaces and lead screws, and apply lithium grease to the change gears.</span></div><div><font face="arial"><br /></font></div><div><font face="arial"><b>Repairs</b></font></div><div><font face="arial">The printed board assembly of the mini lathe is commonly marked SCR-340 with a sticker on the heatsink. The silkscreen on my printed board is </font><span style="font-family: arial;">marked FzDz Ver1.33.16.08.08 A, but this seems to vary between manufacturers.</span></div><div><font face="arial">The circuit and printed board design appears to be a copy of the KBLC-240D. Unfortunately, the component names are different.</font></div><div><font face="arial"><a href="http://andysmachines.weebly.com/variable-speed-controls.html">Information for KBLC-240D can be found here</a>.</font></div><div><font face="arial"><b><br /></b></font></div><div><font face="arial"><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj-mkDD2FUoaoPr83EEBfCAGBy6PnPSde97fIn3Z6vI8glTAoFFV08Os45Ts_vSvlAYnoktjRBrGZW3wckdC5LEAo8t_j1OpRpc9AjjhhlCaNKXPqvFqkK3WrE0yG2vZPvUd0QQXKWFXxhY/s3087/Mini+Lathe+CJ0618+Partial+Circuit+Diagram.png" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" data-original-height="2127" data-original-width="3087" height="176" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj-mkDD2FUoaoPr83EEBfCAGBy6PnPSde97fIn3Z6vI8glTAoFFV08Os45Ts_vSvlAYnoktjRBrGZW3wckdC5LEAo8t_j1OpRpc9AjjhhlCaNKXPqvFqkK3WrE0yG2vZPvUd0QQXKWFXxhY/w256-h176/Mini+Lathe+CJ0618+Partial+Circuit+Diagram.png" width="256" /></a></div>If the lathe trips an RCD, or otherwise fails to turn on, disconnect mains power and check the fuse. DO NOT replace the fuse without further inspection. Check the motor is free of swarf, then check for blown components on the main board.</font></div><div><font face="arial"><br /></font></div><div><font face="arial">Use a multimeter to diode check D2 and D3, and check resistance of R8. Replace any blown components.</font></div><div><font face="arial"><br /></font></div><div><font face="arial"><br /></font></div><div><br /></div><div><br /></div><div><b><span style="font-family: arial;"><br /></span></b></div><div><b><span style="font-family: arial;"><br /></span></b></div><div><b><span style="font-family: arial;">Further modifications</span></b></div><div><ul style="text-align: left;"><li><span style="font-family: arial;">A sheet metal chip tray was added to the front of the carriage to prevent swarf building up on the ways.</span></li><li><a href="http://levysounddesign.blogspot.com/2021/01/digital-readout-dro-for-mini-lathe.html"><span style="font-family: arial;">DRO made with cheap digital calipers</span></a></li></ul></div>Michael Levyhttp://www.blogger.com/profile/18217504205268410755noreply@blogger.comtag:blogger.com,1999:blog-1840519511821046231.post-19879144891977466352016-10-04T16:12:00.004+11:002020-06-19T11:14:58.216+10:00SMD Beak<font face="arial"><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjltWGyJAdw_G9_btr9Ei6hRiPpKtEEqB3RmmuX70s_QKTqcN5SGvuUAZLuB1ATRcqUwqmJ-7tsGxoA9Nw9d5OJ-wjSbx5NY8dPHMLlh3MOcabaAkvDi6ng8h5iljBwX9x9t9Ija66EyL8M/s1600/SMD+Beak+1.jpg" style="margin-left: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="375" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjltWGyJAdw_G9_btr9Ei6hRiPpKtEEqB3RmmuX70s_QKTqcN5SGvuUAZLuB1ATRcqUwqmJ-7tsGxoA9Nw9d5OJ-wjSbx5NY8dPHMLlh3MOcabaAkvDi6ng8h5iljBwX9x9t9Ija66EyL8M/w500-h375/SMD+Beak+1.jpg" width="500" /></font></span></a></div>
<font face="arial"><span><br /></span>
<span>An SMD Beak is used to hold a surface mount device in place as you solder it, leaving both of your hands free to hold your iron and solder. <a href="http://vpapanik.blogspot.com.au/2015/02/the-smd-beak.html" target="_blank">The idea came from Vpapanik</a>. The beak must be sharp in order to grip the device you are soldering, and have enough mass so as not to be moved easily. My design is adjustable and folds flat after use.</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhEuSXuV2JVrtJUiW0rXPCNxUNQMihCJ82B9w5VprAX6eGHFOXk7UAQR2XGTF66B3nAvyEgd_WMsVpWvLupqCaQ8lq1IWF-kdga5MvscUoa9QZ44gP1AdrskzYU8lb10LxSgOM3xQZz179R/s1600/SMD+Beak+2.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="150" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhEuSXuV2JVrtJUiW0rXPCNxUNQMihCJ82B9w5VprAX6eGHFOXk7UAQR2XGTF66B3nAvyEgd_WMsVpWvLupqCaQ8lq1IWF-kdga5MvscUoa9QZ44gP1AdrskzYU8lb10LxSgOM3xQZz179R/s200/SMD+Beak+2.jpg" width="200" /></font></span></a></div>
<font face="arial"><span>3mm mild steel was cut to 10mm strips.</span><br />
<span>Base is tack welded in place.</span><br />
<span>Holes drilled to fasten the arm with a wing nut.</span><br />
<span>Beak arm sharpened to a point.</span></font>Michael Levyhttp://www.blogger.com/profile/18217504205268410755noreply@blogger.comtag:blogger.com,1999:blog-1840519511821046231.post-89934750174202425912016-10-04T15:04:00.005+11:002020-06-19T11:16:01.594+10:00Tools for the Electronics Tradesman<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhNNcR89gc8R6TVwgHOL7NPFN2DfyEIZkcdymQxrY3gz7tTDd56022WaK6_KV1QQrlFF1lsGiG6x7mINMU8oHI3Tpu37PvCorv9f3KDDb4QEnhK306SS675v6IsRJ0PnzTDyu5zmsq2remo/s1600/Workspace.jpg" style="margin-left: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="469" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhNNcR89gc8R6TVwgHOL7NPFN2DfyEIZkcdymQxrY3gz7tTDd56022WaK6_KV1QQrlFF1lsGiG6x7mINMU8oHI3Tpu37PvCorv9f3KDDb4QEnhK306SS675v6IsRJ0PnzTDyu5zmsq2remo/w625-h469/Workspace.jpg" width="625" /></font></span></a></div>
<font face="arial"><span>As with any trade, purchasing the right tools for a job in the electronics industry is essential. Here I have listed the tools that I believe are necessary for an apprentice starting work in the electronics industry.</span><br />
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<span>The tools for the electronics tradesman will vary between disciplines. The majority of work I do is amplifiers repairs, with some fabrication of enclosures and the like. An embedded design engineer would have tools specific to that area, but many of the tools listed here would still be relevant.</span><br />
<span><span><br /></span><span>You will not need to purchase all of these tools at once, rather you will add each tool as it is needed </span><span>over the course of an apprenticeship. A soldering station will likely be supplied by your employer. A nice pair of side cutters and a set of insulated screwdrivers are essential. </span><span>As soon as you can afford it, p</span><span>urchase a large rolling tool chest with sliding drawers.</span></span><br />
<span><span><br /></span><span>As you accumulate more tools, careful attention should be paid to organisation. It saves a lot of time if tools used for particular tasks are grouped together.</span></span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhns0ihx_nzhZgkgEI73kZrSfxicEDYvj_x_j0TCNkQKTOeQYMh6cUuMRzs01_72wpHKCk_uQV3SpS6ovI2wV2QvsGZe_1K1dhexOWIn7IcNX90JECp3H8kC5zkyYE6FYGSIpnd_wRk0hij/s1600/Toolbox+01.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="150" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhns0ihx_nzhZgkgEI73kZrSfxicEDYvj_x_j0TCNkQKTOeQYMh6cUuMRzs01_72wpHKCk_uQV3SpS6ovI2wV2QvsGZe_1K1dhexOWIn7IcNX90JECp3H8kC5zkyYE6FYGSIpnd_wRk0hij/s200/Toolbox+01.jpg" width="200" /></font></span></a></div>
<font face="arial"><span><b>Toolbox Top:<i> </i></b><i>large frequently used tools.</i></span><br />
<span>Probes + Clip leads for multimeters.</span><br />
<span>Two Multimeters; Measure voltage and current at the same time or monitor dual supply rails.</span><br />
<span>Discharge resistor 25W 40R, used to discharge supply capacitors before working on a PCB.</span><br />
<span>Helping hands for holding connectors when terminating.</span><br />
<span><a href="http://levysounddesign.blogspot.com.au/2016/10/smd-beak.html" target="">SMD beak</a>; a small pointed arm that holds SMDs in place while soldering.</span><br />
<span><span>Small socket set, </span><span>Hacksaw and safety glasses.</span></span><br />
<span>Stanley security driver set.</span><br />
<span>IR thermometer; check heatsink thermal protect circuits are working correctly.</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjB-vEO2jGZo-p4ZE3t6pxvF7-dtp9L3DW3xSphkWMXH3mOiaYL15GZm8OtBaFuVsNgz81w6Jrrb7b2Wi6mrQeKCEul2NPGhJfJk2u0nbRx9Kgyg8iR6JZukd7L6Zw_o07Dg6P-6TgY_V8X/s1600/Toolbox+02.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="150" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjB-vEO2jGZo-p4ZE3t6pxvF7-dtp9L3DW3xSphkWMXH3mOiaYL15GZm8OtBaFuVsNgz81w6Jrrb7b2Wi6mrQeKCEul2NPGhJfJk2u0nbRx9Kgyg8iR6JZukd7L6Zw_o07Dg6P-6TgY_V8X/s200/Toolbox+02.jpg" width="200" /></font></span></a></div>
<font face="arial"><span><b>Small top drawers: </b><i>Small tools.</i></span><br />
<span>Combination spanner set.</span><br />
<span>Punches, deburring tool.</span><br />
<span>Small screwdriver set.</span><br />
<span>Screwdriver bits.</span><br />
<span>IDC removal tool, Tweezers, Prying tools.</span><br />
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<span><font face="arial">Torch, Otoscope for inspecting small devices.</font></span></div>
<font face="arial"><span>Markers.</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj2TnqEvQ-otgOE5pjLu1GBYZR0fD5YyVaEuHOccPAu4uMNmwGowxgKlJwqNMzhQTW4aMUtXqTsVwUjVc8P6ezTnDsSzJLsNgO4NMWZ8_fkYI4Him7_9w_D2ATKsbKihNsiHBtnBZTBcRXv/s1600/Toolbox+03.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="150" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj2TnqEvQ-otgOE5pjLu1GBYZR0fD5YyVaEuHOccPAu4uMNmwGowxgKlJwqNMzhQTW4aMUtXqTsVwUjVc8P6ezTnDsSzJLsNgO4NMWZ8_fkYI4Him7_9w_D2ATKsbKihNsiHBtnBZTBcRXv/s200/Toolbox+03.jpg" width="200" /></font></span></a></div>
<font face="arial"><span><b>Second drawer: </b><i>Most frequently used tools</i>.</span><br />
<span>Stubby screwdrivers.</span><br />
<span>Insulated screwdriver set.</span><br />
<span>Bullnose pliers, Wire strippers, Long nose pliers.</span><br />
<span>Screw removal pliers.</span><br />
<span>Small long nose pliers.</span><br />
<span>Side cutters *2; keep an old pair for cutting steel wire.</span><br />
<span>Picks.</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjR8mdWw65Fsuy5OBmfTpZgXkp_oWrUS9E11zrdpB3htSb7N6pLFs7YMuYArIiqV4LfGEEh3tlhBbexxi9pFu7M7nrc4hrNFHItmrtVHN1UyFjjnMY4Azo_YZ7vd-gZm4hrUXQGTevsZ8QG/s1600/Toolbox+04.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="150" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjR8mdWw65Fsuy5OBmfTpZgXkp_oWrUS9E11zrdpB3htSb7N6pLFs7YMuYArIiqV4LfGEEh3tlhBbexxi9pFu7M7nrc4hrNFHItmrtVHN1UyFjjnMY4Azo_YZ7vd-gZm4hrUXQGTevsZ8QG/s200/Toolbox+04.jpg" width="200" /></font></span></a></div>
<font face="arial"><span><b>Third drawer: </b><i>Measuring tools</i>.</span><br />
<span>Vernier calipers.</span><br />
<span>Micrometer.</span><br />
<span>Square and 12" Ruler.</span><br />
<span>Caliper set.</span><br />
<span>Screwdriver extension bit.</span><br />
<span>Microphone for testing audio inputs.</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhW8w96rn0Ocycr8edE7WdViBW7nyCoY9z3ULD7h544a8wETWFuLDXsdYHF00-z4eBQhF9NSzu9fddN1bcx2Lgg8jTGF4ru8dMU8xoBZmLj147T1jBkwJJ5n6em8Aau25hbPCxuSXnh31s6/s1600/Toolbox+05.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="150" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhW8w96rn0Ocycr8edE7WdViBW7nyCoY9z3ULD7h544a8wETWFuLDXsdYHF00-z4eBQhF9NSzu9fddN1bcx2Lgg8jTGF4ru8dMU8xoBZmLj147T1jBkwJJ5n6em8Aau25hbPCxuSXnh31s6/s200/Toolbox+05.jpg" width="200" /></font></span></a></div>
<font face="arial"><span><b>Fourth drawer: </b><i>Fabrication tools.</i></span><br />
<span>Files + wire brush or file card.</span><br />
<span>Tin snips.</span><br />
<span>Multigrips.</span><br />
<span>Large shifter.</span><br />
<span>Screwdrivers.</span><br />
<span>Ball peen hammer.</span><br />
<span>25mm scraper.</span><br />
<span>Drill bits.</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjwgGXb5HuDgvsWN1HbD73CLCrPnUqbNUWtHwmmRvO7s-SRh-TNKqoSdOr-6FfMPnhhv_mfjp9pF7AA_x_pyJB3hZBf1RSHk2ctzM_1Y0Q2nKHDNmvVYncuU6iWzeK20asipTfWIVV7_UWb/s1600/Toolbox+06.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="150" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjwgGXb5HuDgvsWN1HbD73CLCrPnUqbNUWtHwmmRvO7s-SRh-TNKqoSdOr-6FfMPnhhv_mfjp9pF7AA_x_pyJB3hZBf1RSHk2ctzM_1Y0Q2nKHDNmvVYncuU6iWzeK20asipTfWIVV7_UWb/s200/Toolbox+06.jpg" width="200" /></font></span></a></div>
<font face="arial"><span><b>Fifth drawer:<i> </i></b><i>Infrequently used tools.</i></span><br />
<span>Analog multimeter.</span><br />
<span>Cable tester.</span><br />
<span>Wooden mallet.</span><br />
<span>Large socket set.</span><br />
<span>Stanley knife blades.</span><br />
<span>Hacksaw blades.</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEje0xKXrZzaYHLWMHczZNrw6qrtRuckKGoeQ2aGSOSLZ0tXDg59GKe7xIaxEV02ItbSXlaY2zV5ou1utLWEpcxjjV-NvD7ymBzFpYcwtM3ToORrAaQi-3-B1UxkAWrzEzpFfOcHRanLamNC/s1600/Gear.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="150" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEje0xKXrZzaYHLWMHczZNrw6qrtRuckKGoeQ2aGSOSLZ0tXDg59GKe7xIaxEV02ItbSXlaY2zV5ou1utLWEpcxjjV-NvD7ymBzFpYcwtM3ToORrAaQi-3-B1UxkAWrzEzpFfOcHRanLamNC/s200/Gear.jpg" width="200" /></font></span></a></div>
<font face="arial"><span><b>Above workbench: </b><i>Test equipment</i></span><br />
<span>Oscilloscope.</span><br />
<span><a href="http://levysounddesign.blogspot.com.au/2016/04/octopus-tester-component-curve-tracer.html">Curve tracer</a> for power-off in-circuit testing.</span><br />
<span><a href="http://levysounddesign.blogspot.com.au/2016/04/mains-current-limiting-bulbs.html">Mains current limiter.</a></span><br />
<span><a href="http://levysounddesign.blogspot.com.au/2016/04/speaker-impedance-measurement.html">Speaker impedance tester.</a></span><br />
<span>Dual rail lab supply.</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg4VFhAjHxhN0UMt6UItHpHNQwlc3FptrFlF7qBczPowdWrE-y2SU05eTKrMskT7VgG_93V02tA70WuHXPehwhaSDvpcSxJoIg2AxR4nlOr_bIIlk87jhT0j7j8M5mlLx2vrZyvApXqPtAd/s1600/Leads.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="150" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg4VFhAjHxhN0UMt6UItHpHNQwlc3FptrFlF7qBczPowdWrE-y2SU05eTKrMskT7VgG_93V02tA70WuHXPehwhaSDvpcSxJoIg2AxR4nlOr_bIIlk87jhT0j7j8M5mlLx2vrZyvApXqPtAd/s200/Leads.jpg" width="200" /></font></span></a></div>
<font face="arial"><b><span>Above workbench: </span></b><br />
<span>Device programmers, Connectors, Test CDs.</span><br />
<span>Scope probes and <a href="http://levysounddesign.blogspot.com.au/2016/02/differential-scope-probes.html">Differential Scope Probes</a></span><br />
<span>Alligator leads.</span><br />
<span>Solder, solder wick, solder sucker.</span><br />
<span>Containers for holding screws.</span><br />
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<font face="arial"><span>A good quality temperature controlled soldering iron is essential. I use the JBC CD2BB, as it has easily removable tips and heats up very quickly.</span><br />
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<font face="arial"><span>A PC modified with a power button on the rear of the case allows easy access to all ports.</span><br />
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<font face="arial"><span>I also find it necessary to wear a tool belt, so that I always have these items on hand:</span><br />
<span>Markers and pen.</span><br />
<span>Small note pad.</span><br />
<span>Tape measure (for measuring freight boxes).</span><br />
<span>Folding stanley knife.</span><br />
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<span>A lot can be learned from tools of other trades; Tom from OX Tools produced a great <a href="https://youtu.be/7xX69e0sawE">video on tools for the apprentice machinist.</a></span></font>Michael Levyhttp://www.blogger.com/profile/18217504205268410755noreply@blogger.comtag:blogger.com,1999:blog-1840519511821046231.post-47477959164379963102016-04-21T22:54:00.001+10:002020-06-19T11:16:25.081+10:00Speaker Impedance Measurement<div class="separator" style="clear: both; text-align: center;">
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEimh0L01CjuCoUElc-jFz4KezqkE4-D4RWwKlr66-K4cYIykEESdjg7pCGaV9Z3_kUK2gdalhaf_R9Md2fHnHdhoJfInqRT02MV1eQ8qo0uYba9IaN8riJUmpslfD2XDcVcuKSIZwRfiDmr/s1600/SX100%252B.png" style="margin-left: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="306" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEimh0L01CjuCoUElc-jFz4KezqkE4-D4RWwKlr66-K4cYIykEESdjg7pCGaV9Z3_kUK2gdalhaf_R9Md2fHnHdhoJfInqRT02MV1eQ8qo0uYba9IaN8riJUmpslfD2XDcVcuKSIZwRfiDmr/w625-h306/SX100%252B.png" width="625" /></font></span></a></div>
<font face="arial"><span>Comparing two speakers side by side is the best way diagnose a fault, but it's likely you will not always be able to do this. Speaker impedance measurement software is a useful tool for recording the characteristics of a woofer or speaker box for future comparison.</span><br />
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<span>Different from a frequency response graph, an impedance graph indicates load on the amplifier vs frequency. </span></span><span>Software produces a sine sweep (or pink noise). This signal is taken from the PC output and amplified. Current (voltage across a known resistance) and voltage of the output is measured, and fed back into the PC. Software then calculates Impedance and </span><span>compares it </span><span>to the source signal.</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhdHfR4BRAjgDkZi_GZrIFQIbD2qi8QGu7DBrYDbUUVyIdz9cQb_Nuae4sOxq8sOHLoToUptez7hyeca4CarQ40f9SNKuBWKQ_KcDJsjuHDiLhqTRkbuVWgDc2vfGz16UZCvJAnvywH8p9z/s1600/ZX3-90B+repair+13744+xovr+fault.png" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="96" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhdHfR4BRAjgDkZi_GZrIFQIbD2qi8QGu7DBrYDbUUVyIdz9cQb_Nuae4sOxq8sOHLoToUptez7hyeca4CarQ40f9SNKuBWKQ_KcDJsjuHDiLhqTRkbuVWgDc2vfGz16UZCvJAnvywH8p9z/s200/ZX3-90B+repair+13744+xovr+fault.png" width="200" /></font></span></a></div>
<font face="arial"><span>Here is a comparison of a speaker before (gray) and after repairing a fault in the crossover (black). Note the significant difference in impedance at 4kHz.</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj2DZjKoZ88hW1oL16gXOyyp5AtFDQPRdE6HB1DkzczmLR41UuApNAvAVBcZmG5HNfWJR3Bf66Peke3Z4KmSv-ysxMrrUUbk9U3xIZPlia37-gIlNW5I2ubTCDkXs3vD_fwYPBHWA-litHx/s1600/capture1.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="112" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj2DZjKoZ88hW1oL16gXOyyp5AtFDQPRdE6HB1DkzczmLR41UuApNAvAVBcZmG5HNfWJR3Bf66Peke3Z4KmSv-ysxMrrUUbk9U3xIZPlia37-gIlNW5I2ubTCDkXs3vD_fwYPBHWA-litHx/s200/capture1.jpg" width="200" /></font></span></a></div>
<font face="arial"><span><a href="http://www.artalabs.hr/" target="_blank">LIMP by Artalabs</a> is the software used in this project.</span><br />
<span>It has great calibration tools, and a thorough tutorial.</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgo982b25diSzPUwRBGBhPF9be-PIOrc7mRq1vIeNYjW9JJz1GWJ1zIh1XUq7fzVr13EiNexzIkAq1Gn92A8Pjb-qtqrzeLhFJM0-cyIqaaAP4ZXWK6q5pTWlsY3hnuat0iUVMxCGn-z0WP/s1600/IMG_20160912_075506.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><font face="arial"><img border="0" height="150" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgo982b25diSzPUwRBGBhPF9be-PIOrc7mRq1vIeNYjW9JJz1GWJ1zIh1XUq7fzVr13EiNexzIkAq1Gn92A8Pjb-qtqrzeLhFJM0-cyIqaaAP4ZXWK6q5pTWlsY3hnuat0iUVMxCGn-z0WP/s200/IMG_20160912_075506.jpg" width="200" /></font></a></div>
<font face="arial"><span>My example; Speakon connects to woofer / speaker box to be tested, 3.5mm TRS are used for simple interfacing with PC.</span><br />
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<font face="arial"><span><span>Constructed from several other PCB projects (TDA7294 50W amplifier, and Differential Scope Probe circuits), with point to point wired linear supply for simplicity. These were just things I had on hand at the time of construction.</span></span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhjRPjUfO9EjjUv70En2mGUWzMkFyygWXJ6jkv5BuZNSUtWHwzT3jtzYx2KV_Sy73LTPqhZ52CJe494u2gQvBkFNzzzEwVhG7vZtlhYHYew5qXg2RR7e8ixOmbbzegTEYZBcMS3UtSP88GW/s1600/LEVY+Speaker+Impedance.png" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="145" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhjRPjUfO9EjjUv70En2mGUWzMkFyygWXJ6jkv5BuZNSUtWHwzT3jtzYx2KV_Sy73LTPqhZ52CJe494u2gQvBkFNzzzEwVhG7vZtlhYHYew5qXg2RR7e8ixOmbbzegTEYZBcMS3UtSP88GW/s200/LEVY+Speaker+Impedance.png" width="200" /></font></span></a></div>
<font face="arial"><span>Output of the amplifier passes through a 1R 10W sense resistor. </span><br />
<span>Sense outputs are voltage dividers, and PC mic level inputs are buffered.</span></font>Michael Levyhttp://www.blogger.com/profile/18217504205268410755noreply@blogger.comtag:blogger.com,1999:blog-1840519511821046231.post-4849157539393244262016-04-13T00:41:00.001+10:002020-06-19T11:16:55.195+10:00Octopus Tester / Component Curve Tracer<div class="separator" style="clear: both; text-align: center;">
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgJ43Ie3y4c-k4KeoCxNr5HKD5Y4kSqNjytCkdqD5DMRXixW_qZVrBvHcLtVBTrcVkt3El6iBFiTKe755CNiVYBdUPcbjc1DW0UuZK17TjPZBL3_91EIxcUPtIR6FQhfUkhguvRiCcWAzyt/s1600/LEVY+Octopus+Tester.png" style="margin-left: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="454" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgJ43Ie3y4c-k4KeoCxNr5HKD5Y4kSqNjytCkdqD5DMRXixW_qZVrBvHcLtVBTrcVkt3El6iBFiTKe755CNiVYBdUPcbjc1DW0UuZK17TjPZBL3_91EIxcUPtIR6FQhfUkhguvRiCcWAzyt/w625-h454/LEVY+Octopus+Tester.png" width="625" /></font></span></a></div>
<font face="arial"><span><span>The Octopus Tester </span><span> is an accessory for an oscilloscope which permits a </span><span>method of power-off, in-circuit testing (ie; it is </span><span>used to test damaged equipment without powering it up, and without removing components). Touching the probes to a device will produce a </span><span>voltage-vs-current characteristic diagram on the scope screen, so a </span><span>component under test can be quickly compared to a known working component simply by comparison of the image on screen.</span></span><br />
<span>Example:</span><br />
<span>One channel of a stereo amplifier is not working. You can use the Octopus Tester to compare suspect transistors on the blown channel to the same transistors on the working channel. Each time you find a damaged device, remove it, and test all components to which it was immediately connected (Resistors should be checked with a multimeter).</span><br />
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<font face="arial"><span>The mains transformer produces a 12V 50Hz sine wave with a floating output. This signal sweeps the Device Under Test, and an image is produced on an oscilloscope in X-Y mode. The voltage across the DUT is shown on the X axis, and the current through the DUT (measured as voltage drop across a known resistance) is shown on the Y axis.</span><br />
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<span>Shown here is a diode. Voltage across the diode increases until the diode turns on at 0.6V. Current through the diode is then at maximum.</span></span><br />
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<font face="arial"><span>When testing components in circuit, there will typically be resistive, and reactive elements to the image on screen. You can first familiarise yourself by testing components out of circuit.</span><br />
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<span>After using the device for a short time, you will begin to associate the images on screen with the devices you are testing, and the surrounding circuitry.</span><span> </span><span>It then becomes simple to quickly troubleshoot faulty circuits, based on knowledge of the devices you are probing.</span></span><br />
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<font face="arial"><span>The octopus circuit is housed in a small plastic enclosure. BNC connect to scope X and Y inputs, banana sockets are for regular multimeter probes.</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEin90BNg3xgftQ-RmaVIQT4Cl9AxIfGZVgCORpoBeqRTECO8ENLXc46KrlAJ5ZSmOQe2MPPQes16YoReZCDyMHMfuplVfk4C4SJazMp_66ANmpe-4rQAOtYHRTJqqeXRdzTCNFFsyVUMpEC/s1600/IMG_20160412_223059.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="112" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEin90BNg3xgftQ-RmaVIQT4Cl9AxIfGZVgCORpoBeqRTECO8ENLXc46KrlAJ5ZSmOQe2MPPQes16YoReZCDyMHMfuplVfk4C4SJazMp_66ANmpe-4rQAOtYHRTJqqeXRdzTCNFFsyVUMpEC/s200/IMG_20160412_223059.jpg" width="200" /></font></span></a></div>
<font face="arial"><span>Due to the simplicity of the circuit, point to point wiring is the quickest method of construction. Be sure to ground your unit correctly.</span><br />
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<font face="arial"><span>Setting up the octupus tester.</span><br />
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<font face="arial"><span>Ensure that your scope is set to DC coupling, and that the circuit you are testing has no other path to ground, ie; disconnect all power / audio / data cables to the unit.</span><br />
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<span>It's also necessary to discharge any large caps before testing (You cannot damage anything, but your trace will disappear from the screen).</span><br />
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<font face="arial"><span><span>Some scopes come with a curve tracing function build in. Set-up and use of the </span><span>component test function of the Hung Chang scope is the same as most other brands I have used.</span></span><br />
<span>I have two scopes on my test bench, the Hung Chang pictured is used solely for this function, such is the frequency of it's use.</span><br />
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<font face="arial"><span><span>This is a schematic of the Hung-Chang 3502C scope front end, from which I copied the design of my device. The component testing circuit is highlighted.</span><span></span></span><br />
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Michael Levyhttp://www.blogger.com/profile/18217504205268410755noreply@blogger.comtag:blogger.com,1999:blog-1840519511821046231.post-13877461143774211802016-04-07T09:13:00.008+10:002021-08-18T07:06:40.137+10:00Mains Current Limiting Bulbs<div class="separator" style="clear: both; text-align: center;">
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgGeRSEr4r82QeKDmWI5n8vRR_hynW5d9tyYUuIrQc8ds7YCCeu5tp-4ML4LJ9Q1eIRcoDEOwa0LqQSWPF5yuhBllhjMLupaN0D9zFSxw8UQ-dXUH5oJrVq3lV78FJZEf33LqyxIM2BhR0A/s1600/LEVY+Mains+Current+Limit.png" style="margin-left: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="454" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgGeRSEr4r82QeKDmWI5n8vRR_hynW5d9tyYUuIrQc8ds7YCCeu5tp-4ML4LJ9Q1eIRcoDEOwa0LqQSWPF5yuhBllhjMLupaN0D9zFSxw8UQ-dXUH5oJrVq3lV78FJZEf33LqyxIM2BhR0A/w625-h454/LEVY+Mains+Current+Limit.png" width="625" /></font></span></a></div>
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<font face="arial"><span>When working on a mains electricity powered device, you will need to safely power up the unit by limiting mains current.</span><span><span><br /></span>
<span><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgbnISSrlAVse0vlXXYt4GgWm-0npYzWa4NgNi8soMgOwEFQ-VTr9PAetR6xqgBT2T10av_BG90PcOJYk_uC7fm9RCpXn2NxCys01YKolgx9_J3zwRKrRQsDkrSYXGC1RLpb7OneQjMhNb5/s602/main-qimg-130a4b534070336f37759f3af39ff71f+%25281%2529.gif" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" data-original-height="467" data-original-width="602" height="155" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgbnISSrlAVse0vlXXYt4GgWm-0npYzWa4NgNi8soMgOwEFQ-VTr9PAetR6xqgBT2T10av_BG90PcOJYk_uC7fm9RCpXn2NxCys01YKolgx9_J3zwRKrRQsDkrSYXGC1RLpb7OneQjMhNb5/w200-h155/main-qimg-130a4b534070336f37759f3af39ff71f+%25281%2529.gif" width="200" /></a></div>This is achieved here by placing a non linear load in series with the unit.</span></span></font><div><font face="arial"><span><span><br /></span></span></font></div><div><font face="arial"><span><span>The resistance of the incandescent globes increases as the current through them increases, so under normal conditions (where the device under test does not draw a large current) the globes will not light up.</span></span></font></div><div><span style="font-family: arial;"><br /></span></div><div><div><font face="arial"><span><span><div>This graph indicates voltage drop across the globe with respect to current.</div><div><br /></div><div><br /></div><div><br /></div><div><br /></div>Under a fault condition, the device under test will draw a large current, and the globes will light up. This reduces the voltage drop across the device under test, preventing further damage to the device.</span></span></font></div><div><br /></div><div><font face="arial"><span>
<span>Maximum current (at short circuit) can be calculated:</span></span><br />
<span>For one 100W bulb</span><br />
<span>I = P/V = 100W/240V</span><br />
<span>I = 0.4167A</span><br />
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<span>The unit can be constructed from several batten fixtures.</span><br />
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<span>4* 100W incandescent globes is enough to provide idle current for a very large amplifier.</span></span><br />
<span>If a lower current limit is required, simply unscrew a few globes.</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjFct0lPM6B4ROFNrX0D2Xexw7TUL1ILcSZj8y7q0p3urt-XXwndemYKbsvaHciRFDiY9I6WID2jiYCpzxDJbvpNfjdOiNHAmwqY_5DcwjU8LfpSgiz6lvhXHAHCzh6R736ZkzU7yCpy5Sw/s1600/IMG_20160407_085416.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="112" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjFct0lPM6B4ROFNrX0D2Xexw7TUL1ILcSZj8y7q0p3urt-XXwndemYKbsvaHciRFDiY9I6WID2jiYCpzxDJbvpNfjdOiNHAmwqY_5DcwjU8LfpSgiz6lvhXHAHCzh6R736ZkzU7yCpy5Sw/s200/IMG_20160407_085416.jpg" width="200" /></font></span></a></div>
<font face="arial"><span>Current limiting bulbs installed on test bench.</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgwPrK-SreIiXyHGJpPMPRUxf5WsiaiIxDQyq1wW9lvByVTcEvZyMR-qBSQoDjW-k-7O6u8J-q9-HrOMmGQM28npuuwL-qeub3z7jM9VtuALV_j29WjnWjcdcIPMs6XeiQ8NqwGAAfGGuep/s1600/IMG_20160407_085946.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="112" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgwPrK-SreIiXyHGJpPMPRUxf5WsiaiIxDQyq1wW9lvByVTcEvZyMR-qBSQoDjW-k-7O6u8J-q9-HrOMmGQM28npuuwL-qeub3z7jM9VtuALV_j29WjnWjcdcIPMs6XeiQ8NqwGAAfGGuep/s200/IMG_20160407_085946.jpg" width="200" /></font></span></a></div>
<font face="arial"><span>Example of fault in device under test</span><br />
<span>(here provided by a short circuit).</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgaT4Teib8aCFUojgJ93XF270_kbERzovg-_ty3bGxCXBAurXVh8Z6ANmmeFjZ1cE3HEfcL_4QPtMHBBKzqpKQB_7dtC0X680XQBYo6xbbjaHZ-WP1mqZM8Ie4nt2rvRg1O2HWtIJatqmJW/s1600/IMG_20160825_180830.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="151" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgaT4Teib8aCFUojgJ93XF270_kbERzovg-_ty3bGxCXBAurXVh8Z6ANmmeFjZ1cE3HEfcL_4QPtMHBBKzqpKQB_7dtC0X680XQBYo6xbbjaHZ-WP1mqZM8Ie4nt2rvRg1O2HWtIJatqmJW/s200/IMG_20160825_180830.jpg" width="200" /></font></span></a></div>
<font face="arial"><span>Alternatively, this device can be constructed as a rack unit.</span><br />
<span>Switches are wired such that each bulb can be taken out of circuit in order to provide the correct current limit.</span><br />
<span>A meter displays output voltage and current.</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhl2A2Eb77bkN0bTyoo0ExoSBGrR35H1JTeiIYLqOmg4CFROSnxG2_hApbQSc7x8qqN5PZpO-rg1wVzSfaHrjN3rNBmzlNGD_OEwZzqsaHFscTZrxQ5XFXNbEG5xbC3egDjdmF9oWHfwKMs/s1600/IMG_20160825_180849.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="150" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhl2A2Eb77bkN0bTyoo0ExoSBGrR35H1JTeiIYLqOmg4CFROSnxG2_hApbQSc7x8qqN5PZpO-rg1wVzSfaHrjN3rNBmzlNGD_OEwZzqsaHFscTZrxQ5XFXNbEG5xbC3egDjdmF9oWHfwKMs/s200/IMG_20160825_180849.jpg" width="200" /></font></span></a></div>
<font face="arial"><span>Bulbs are mounted in lamp-stand fittings.</span><br />
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<span>Please note, this method cannot be employed on some "universal" switch mode power supplies, as the supply may enter a mode designed for a different voltage mains supply (ie; a 240V supply might think it's receiving 110V). I have found this only rarely to be problematic.</span></span></font></div></div>Michael Levyhttp://www.blogger.com/profile/18217504205268410755noreply@blogger.comtag:blogger.com,1999:blog-1840519511821046231.post-32731020114211895562016-02-08T23:28:00.002+11:002020-06-19T11:17:49.362+10:00Differential Scope Probes<div class="separator" style="clear: both; text-align: center;">
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<font face="arial"><img border="0" height="468" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgYMNfl-XuFpctGqIrGqghNpgamGKhjbK7QaBOUhjJmSPk3NAcn9iMkb2QDNQn2_DsxDp3-X0hXuXCDxFz67zqo5Ibo0Ugt3AZ5A4qaYqL75c65SP7Ue5oD49xbFMC5U0lnwiJuKVR4X5zE/w625-h468/IMG_20160208_230316.jpg" width="625" /></font></div>
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<span>A differential scope probe is used when a signal cannot be analysed relative to ground. An example of this is the output of a bridged amplifier; neither of the output terminals can be connected to the scope ground, and reading each separately may not be an accurate representation of the signal.</span><br />
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<span>This scope probe is DC coupled, with an input impedance over 1M, and has a relatively low noise floor. A single quad op-amp chip provides input buffers, differential, and has provision to split a single floating supply for dual rail operation. My example is a x100 probe using a 12V plug pack. Input voltage divider resistor values and rail voltages can be changed to suit your needs.</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiytgX01yMWX28bKc3QRk_qaBUmkyBb9UH-IkgFaEj6JXf66BBUtnW-CFsy2SSjillZKV0saq3WR5RO8uNpy_OGI4UJ8LK7zIn3KPKMo9Qs4FfI5-OSRZ9oQDqel44QZyzte2QN0Q3y5WK1/s1600/LEVY+Diff+Scope+Probe+Schematic.png" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="137" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiytgX01yMWX28bKc3QRk_qaBUmkyBb9UH-IkgFaEj6JXf66BBUtnW-CFsy2SSjillZKV0saq3WR5RO8uNpy_OGI4UJ8LK7zIn3KPKMo9Qs4FfI5-OSRZ9oQDqel44QZyzte2QN0Q3y5WK1/s200/LEVY+Diff+Scope+Probe+Schematic.png" width="200" /></font></span></a></div>
<font face="arial"><span> Schematic</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEioiJTaPBfusMMlWfoo0sayrM7E3PhAow8hGrNT0tag8WN7QePghsFrPIaXhkTpmDkl_4-0KGNsLt2ChoSFBZpJXMrBp-rtY_wXH3PyHWrh-cXAyV-pPZsARbklHyhxEvVzhqb1oVfNakr7/s1600/LEVY+Diff+Scope+Probe+Drawing.png" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEioiJTaPBfusMMlWfoo0sayrM7E3PhAow8hGrNT0tag8WN7QePghsFrPIaXhkTpmDkl_4-0KGNsLt2ChoSFBZpJXMrBp-rtY_wXH3PyHWrh-cXAyV-pPZsARbklHyhxEvVzhqb1oVfNakr7/s200/LEVY+Diff+Scope+Probe+Drawing.png" width="200" /></font></span></a></div>
<font face="arial"><span> Drawing</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhsq48J8yaqWMNbJqPXdpGHpN1V3mzBrKjCdbO2zrwGL61BH0Nz2P18rPDjNrDCSTa660kA2kuuzQnyRbL6KmzmCyG2FwTY940jBBLt0PjD6wDQiTSuQPNmi5jsuKXTdFmBFrmlDnyw8Kte/s1600/LEVY+Diff+Scope+Probe+PCB.png" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhsq48J8yaqWMNbJqPXdpGHpN1V3mzBrKjCdbO2zrwGL61BH0Nz2P18rPDjNrDCSTa660kA2kuuzQnyRbL6KmzmCyG2FwTY940jBBLt0PjD6wDQiTSuQPNmi5jsuKXTdFmBFrmlDnyw8Kte/s200/LEVY+Diff+Scope+Probe+PCB.png" width="200" /></font></span></a></div>
<font face="arial"><span> PCB</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg2XHVFg6wDlHggw-VOigquAZO79Sykdz9v0vSnDxVrT6FXI7G73M9tGlFo6UxziwAAppB5Vj3JObaNWAWk8YJ0l5_JxGOGzXO7E_XQs4ecSb7HK8W97BGAZv_VEAhFCGhwveXKDHmTRA2A/s1600/LEVY+Diff+Scope+Probe+Silkscreen.png" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg2XHVFg6wDlHggw-VOigquAZO79Sykdz9v0vSnDxVrT6FXI7G73M9tGlFo6UxziwAAppB5Vj3JObaNWAWk8YJ0l5_JxGOGzXO7E_XQs4ecSb7HK8W97BGAZv_VEAhFCGhwveXKDHmTRA2A/s200/LEVY+Diff+Scope+Probe+Silkscreen.png" width="200" /></font></span></a></div>
<span><font face="arial">Silkscreen</font></span>Michael Levyhttp://www.blogger.com/profile/18217504205268410755noreply@blogger.comtag:blogger.com,1999:blog-1840519511821046231.post-80037029012033951912014-12-11T23:36:00.005+11:002020-06-19T11:19:21.113+10:00Soundcard Scope Interface<div class="separator" style="clear: both; text-align: center;">
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<div style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiL6fAjRQIDFAqxejDqRDYU8uWrcq3gFGX4bqIILNVDTYdj3xj4pAxIte4U11jVwujxr5NMPg6bTiqoI4MrRNz6n-hPhlVLloM29J1jbhNdbwTLOAMOjYJ0es1pPm8vn_u87sxjmF_ibqOG/s1600/DSC_1137.jpg"><span><font face="arial"><img border="0" height="351" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiL6fAjRQIDFAqxejDqRDYU8uWrcq3gFGX4bqIILNVDTYdj3xj4pAxIte4U11jVwujxr5NMPg6bTiqoI4MrRNz6n-hPhlVLloM29J1jbhNdbwTLOAMOjYJ0es1pPm8vn_u87sxjmF_ibqOG/w625-h351/DSC_1137.jpg" width="625" /></font></span></a></div>
<font face="arial"><span>A computer soundcard can be used as an oscilloscope for testing frequencies below 20kHz. This circuit is a simple protection and control interface, with BNC connectors for oscilloscope probes.</span><br />
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<span>This device is useful for generating a sine tone into audio equipment, and testing the output. The amplitude control knob of the input circuit allows testing of line level audio (1V), and up to speaker level audio (100V).</span><br />
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<span>This circuit is designed to be used on a work site where a full size scope is impractical. It contains only passive components (therefore has a very low input impedance), and as such should be used only for rough troubleshooting.</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi7VsynmNSPz3KLG2dxWZzN9em120xuC7NTxfZUOj1eQyrr7af9DFhMrMpr8kmw1MZLWGXqbgYCsRcQlqO0DYagwQDeoYYMWfPvTRV-jZMwb1_qrlYob1wAV4gdI5O2vo-z7BxYEo-WzqOY/s1600/PortableScopeInterface.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="134" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi7VsynmNSPz3KLG2dxWZzN9em120xuC7NTxfZUOj1eQyrr7af9DFhMrMpr8kmw1MZLWGXqbgYCsRcQlqO0DYagwQDeoYYMWfPvTRV-jZMwb1_qrlYob1wAV4gdI5O2vo-z7BxYEo-WzqOY/s1600/PortableScopeInterface.jpg" width="200" /></font></span></a></div>
<font face="arial"><span>Circuit Diagram</span><br />
<span>The protection circuit ensures voltage at the soundcard input is clipped at 1.2Vp-p.</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEietR6LXSXnXlK4SOuHTn6ac2PPHv_JmImdMm9n2tiYzw6Y_VxC0C4A8tiKnrA2zOz3YzFGP1VP2rzZxXEunzOQXfRgOdA5XLWNuE5PKvlo4KWPpMyQ6gpce0_ymFfrXutNoTXFxjIC7KQ0/s1600/PortableScopeInterfaceBrd.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="134" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEietR6LXSXnXlK4SOuHTn6ac2PPHv_JmImdMm9n2tiYzw6Y_VxC0C4A8tiKnrA2zOz3YzFGP1VP2rzZxXEunzOQXfRgOdA5XLWNuE5PKvlo4KWPpMyQ6gpce0_ymFfrXutNoTXFxjIC7KQ0/s1600/PortableScopeInterfaceBrd.jpg" width="200" /></font></span></a></div>
<font face="arial"><span>Veroboard layout</span><br />
<span>Circuit will mount nicely on the back of a 16mm potentiometer.</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgKdUVo_9ai5nAeVaLkAZ6m83M1gCkqEEUBqs-KwkTRltM8EVs63rpiZz4F5_8eJxUaJzFqQhZDfS9v2xMJbdH1RtMeJRChHRdAlpWFVLWrYxDWYOZggoH3TbyyRPbwx50t6HjS8wRteMoc/s1600/DSC_1135.jpg" style="clear: left; display: inline; float: left; margin-bottom: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="112" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgKdUVo_9ai5nAeVaLkAZ6m83M1gCkqEEUBqs-KwkTRltM8EVs63rpiZz4F5_8eJxUaJzFqQhZDfS9v2xMJbdH1RtMeJRChHRdAlpWFVLWrYxDWYOZggoH3TbyyRPbwx50t6HjS8wRteMoc/s1600/DSC_1135.jpg" width="200" /></font></span></a></div>
<font face="arial"><span>Probe Input Circuit</span><br />
<span>Mounted on a small piece of veroboard.</span><br />
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<span><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhgaRL1bO1ALH9qLN5n6IFZE-hV9ffgZaW83mIh61PrZ1-iWhtisAqZ7CmCph9STdHF6uI0ChFtX9MjgarN8FTqWU5rtO3JyHO9Oph9acOyyCc-uxu51DBU81LPF5EsA5p2rv46NxGea-Y9/s1600/DSC_1129.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><font face="arial"><img border="0" height="112" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhgaRL1bO1ALH9qLN5n6IFZE-hV9ffgZaW83mIh61PrZ1-iWhtisAqZ7CmCph9STdHF6uI0ChFtX9MjgarN8FTqWU5rtO3JyHO9Oph9acOyyCc-uxu51DBU81LPF5EsA5p2rv46NxGea-Y9/s1600/DSC_1129.jpg" width="200" /></font></a></span></div>
<font face="arial"><span>Completed Unit</span><br />
<span>BNC connectors are used to connect test probes.</span><br />
<span>6.5mm socket for use with audio test leads.</span><br />
<span>Banana socket to connect ground lead.</span><br />
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<span>Visual Analyser (Sillanumsoft) is the software I have chosen to use in this project.</span><br />
<span>It is available for free download here: <a href="http://www.sillanumsoft.org/download.htm">http://www.sillanumsoft.org/download.htm</a></span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjegG2nphlOCg42oS96ufKm9WMVfVRHfTA_qW2RcE3-3y6LxXylBygSw6XEgxcCP4kqvjd0kvYXy32v2jeL7H3LFd6BvtdiRda4bb62zJajTXl_THpdHeqMkT8B_Fa2uuJNv26kNBywwX3X/s1600/DSC_1131.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><font face="arial"><img border="0" height="112" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjegG2nphlOCg42oS96ufKm9WMVfVRHfTA_qW2RcE3-3y6LxXylBygSw6XEgxcCP4kqvjd0kvYXy32v2jeL7H3LFd6BvtdiRda4bb62zJajTXl_THpdHeqMkT8B_Fa2uuJNv26kNBywwX3X/s200/DSC_1131.jpg" width="200" /></font></a></div>
<font face="arial"><span>Visual Analyser uses your soundcard to display oscilloscope traces, as well as frequency spectrum. However, the soundcard must first be set up correctly.</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEinYkH_HsH-XXrNj0aVN9os01S9BAq_mlWFiNveApSzPZ9YFGxKhNOQb_W1JdX7ky2ok8vuVh6zYaxaq_EVLwW8i0pEjamhOjTS5pPYlW8NYLdKGKlEmAjfoBX1RRD3cA_6GcT3zl2yGXcd/s1600/capture2.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="111" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEinYkH_HsH-XXrNj0aVN9os01S9BAq_mlWFiNveApSzPZ9YFGxKhNOQb_W1JdX7ky2ok8vuVh6zYaxaq_EVLwW8i0pEjamhOjTS5pPYlW8NYLdKGKlEmAjfoBX1RRD3cA_6GcT3zl2yGXcd/s1600/capture2.jpg" width="200" /></font></span></a></div>
<font face="arial"><span>Right click on your volume control icon in the task bar.</span><br />
<span>Select "Recording Devices".</span><br />
<span>Choose the soundcard input</span><br />
<span>Select "Properties".</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgY2rt8Wrz31C-xHIcM3e_q599gT3u1JjJDAY6SWpgLYmiK3ju02N54MqonyJlBaIxa_C7duNKUzuhqjMs-CV3ELn288aSg1EZmxWHqmU9paMOfbF1_h2YvHUb827O7zj9G1PFlU_NJIfof/s1600/capture3.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="111" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgY2rt8Wrz31C-xHIcM3e_q599gT3u1JjJDAY6SWpgLYmiK3ju02N54MqonyJlBaIxa_C7duNKUzuhqjMs-CV3ELn288aSg1EZmxWHqmU9paMOfbF1_h2YvHUb827O7zj9G1PFlU_NJIfof/s1600/capture3.jpg" width="200" /></font></span></a></div>
<font face="arial"><span>Select the "Custom" tab.</span><br />
<span>Un-check AGC </span><span>(automated gain control).</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgR1BN82GByUuCWlvwYEfth0WVDEzOKuYFnyP_KJNT__cOV91pXzIxxbQFN2EnS1Y0zirbTQ8h8UF4TtUzwaLYnA3TQ2YeW9xhWdph6ktScC7BOk4CGeKkBTX9bWaxEVBuvDfuxM2KJ-SIT/s1600/capture4.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="111" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgR1BN82GByUuCWlvwYEfth0WVDEzOKuYFnyP_KJNT__cOV91pXzIxxbQFN2EnS1Y0zirbTQ8h8UF4TtUzwaLYnA3TQ2YeW9xhWdph6ktScC7BOk4CGeKkBTX9bWaxEVBuvDfuxM2KJ-SIT/s1600/capture4.jpg" width="200" /></font></span></a></div>
<font face="arial"><span>Select "Levels" tab.</span><br />
<span>Increase microphone to 100%.</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjDTpf6D_xEQWoCNDxTJGrfYaY9zh4PR9jBngIS9IQy-w9COmNToR0BqeGdB3UsJdDBUe1qlZXtedtFGsf5ESXEePFCCnROtNAN8P4aqBz_JAo0LfF3mYJ5GTV616smBnfHYlNf31A3hNZc/s1600/capture5.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="111" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjDTpf6D_xEQWoCNDxTJGrfYaY9zh4PR9jBngIS9IQy-w9COmNToR0BqeGdB3UsJdDBUe1qlZXtedtFGsf5ESXEePFCCnROtNAN8P4aqBz_JAo0LfF3mYJ5GTV616smBnfHYlNf31A3hNZc/s1600/capture5.jpg" width="200" /></font></span></a></div>
<font face="arial"><span>Visual Analyser is now ready to use.</span><br />
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WARNING: UNIT GROUND CONNECTS TO PC GROUND.</span><br />
<span>Always connect the ground clip of the device to the chassis of the equipment to be tested. Using the ground clip as a probe will short live circuits to ground through your test device and PC (This goes for any oscilloscope that is not isolated from ground).</span><br />
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NOT FOR USE WITH MAINS A.C.</span></font><br />
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Michael Levyhttp://www.blogger.com/profile/18217504205268410755noreply@blogger.comtag:blogger.com,1999:blog-1840519511821046231.post-49178573691279331932014-10-14T21:40:00.002+11:002020-06-19T11:19:52.534+10:00Epiphone Valve Jr Hot-Rod Modification<div style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjI9oJYZAMtYQh1E1t0bCef9ff_tS30biA04C9JpRQR_hAvnce_gRZKj7G8KsTPRhsHOaLf37v87GmNNwQA-tBaUPQ6FPJSa00vHzqxKC7ximFQ3AOAtqUAx8M5bbJ-v01s5MrScV5XFiVO/s1600/DSC_0987.jpg"><span><font face="arial"><img border="0" height="351" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjI9oJYZAMtYQh1E1t0bCef9ff_tS30biA04C9JpRQR_hAvnce_gRZKj7G8KsTPRhsHOaLf37v87GmNNwQA-tBaUPQ6FPJSa00vHzqxKC7ximFQ3AOAtqUAx8M5bbJ-v01s5MrScV5XFiVO/w625-h351/DSC_0987.jpg" width="625" /></font></span></a></div>
<font face="arial"><span>The Epiphone Valve Jr Hot-Rod is a 5W Class A all valve guitar amplifier with built in spring reverb, and is the less common, and slightly more expensive cousin of the original EVJ.</span><br />
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<span><font face="arial">Although modifications for the original EVJ are found in abundance across the web, the EVJ Hot-Rod seems to have been overlooked by the modding community.</font></span></div>
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<span><font face="arial">The EVJ Hot-Rod has essentially the same amplifier structure as the original model, with an additional 12AX7 to drive the spring reverb unit, a multi-tap transformer output for different speaker impedance, and a "gain" pot on the front panel (which is just a voltage divider after the first preamp stage). With this in mind, modifications for the EVJ Hot-Rod can be easily copied straight from existing documentation for the original EVJ.</font></span></div>
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<span><b><font face="arial">Safety Note</font></b></span></div>
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<span><font face="arial">Power supply capacitors in amplifiers retain charge for weeks. Always discharge capacitors before working on any amplifier. Valve amplifiers are especially dangerous, as the working voltage of the power supply capacitors can be in excess of 300V.</font></span></div>
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<span><font face="arial">A 1K 5W resistor attached to probes can be used to discharge capacitors. Double check with a multimeter before working on the circuit.</font></span></div>
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<span><b><font face="arial">Disassembly of the EVJ Hot-Rod head</font></b></span></div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhEqX174BKc0eAFCdB_rqAMOYuFW1inXSw-vGDBRYvMIqJ2-TeLqwfEC-vBotDiBRRVLPNqZq4k5KKl5UrAsIHUsXl9A507MnUGeKiqbbPkpD2rRnwvl9FMKvxZEM4Q0TQDiZkYJt3SGfuv/s1600/DSC_0988.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="112" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhEqX174BKc0eAFCdB_rqAMOYuFW1inXSw-vGDBRYvMIqJ2-TeLqwfEC-vBotDiBRRVLPNqZq4k5KKl5UrAsIHUsXl9A507MnUGeKiqbbPkpD2rRnwvl9FMKvxZEM4Q0TQDiZkYJt3SGfuv/s1600/DSC_0988.jpg" width="200" /></font></span></a></div>
<font face="arial"><span>Remove screws from the back panel, and pry off (The panel may be hard to remove due to traces of glue on the vinyl).</span><br />
<span>Label the cables to the spring reverb unit for re-assembly, and disconnect.</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjsfyK5ChixJO7cjCkfVJ06y4TpnIo6UKA9UwhiBW7vmX1ENodR6k5-Cox7BTq86FtHSbEXg_qRlol3L2651UaiLKDLsfWvSXkRsk5hI9MDK6GXfvGyqNj5eJPpgmfjxxNm5578sPZVMkoc/s1600/DSC_0989.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="112" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjsfyK5ChixJO7cjCkfVJ06y4TpnIo6UKA9UwhiBW7vmX1ENodR6k5-Cox7BTq86FtHSbEXg_qRlol3L2651UaiLKDLsfWvSXkRsk5hI9MDK6GXfvGyqNj5eJPpgmfjxxNm5578sPZVMkoc/s1600/DSC_0989.jpg" width="200" /></font></span></a></div>
<font face="arial"><span>Remove four plastic caps from the top of the amplifier case.</span><br />
<span>Remove the four screws, and slide the amplifier chassis out of the case.</span><br />
<span>Remove valve covers.</span><br />
<span>Remove valves.</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgytocwKr8ERv3pMYlY1zX_k0GeGWggQZ6ufHcYfCsxuAx_CkKPkDesM__mH7YxTxIUPLtBYEz-HbE6J2kF27apcLwtS4b3O9GMTfVEBR1LzgeUpDQX_M7AF96hjKzvUnFJ7nwPQs16ErO3/s1600/DSC_0990.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="112" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgytocwKr8ERv3pMYlY1zX_k0GeGWggQZ6ufHcYfCsxuAx_CkKPkDesM__mH7YxTxIUPLtBYEz-HbE6J2kF27apcLwtS4b3O9GMTfVEBR1LzgeUpDQX_M7AF96hjKzvUnFJ7nwPQs16ErO3/s1600/DSC_0990.jpg" width="200" /></font></span></a></div>
<font face="arial"><span>Discharge the power supply capacitors by shorting R14 and R15 to ground through a 1K 5W resistor.</span><br />
<span>Label all cables for re-assembly, and disconnect.</span><br />
<span>Remove the input socket retaining screw.</span><br />
<span>Remove the circuit board support screws.</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjQAksferbVcrjoUs-dLC-lKLw3YVBumXsf-ZNI7ilG30L2mYWjOS6L9GkzDUJIrm2MZvk07-iVBi_Mz-rLK0Sc4PxQ-5HWjSs-tzo-6lRsRAs3asR92O09hNhtehPkx5cybwfjlv0VZwXX/s1600/DSC_0997.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><font face="arial"><img border="0" height="112" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjQAksferbVcrjoUs-dLC-lKLw3YVBumXsf-ZNI7ilG30L2mYWjOS6L9GkzDUJIrm2MZvk07-iVBi_Mz-rLK0Sc4PxQ-5HWjSs-tzo-6lRsRAs3asR92O09hNhtehPkx5cybwfjlv0VZwXX/s200/DSC_0997.jpg" width="200" /></font></a></div>
<font face="arial"><span>Remove the circuit board from the chassis.</span><br />
<span>Thoroughly wash the circuit board with isopropyl alcohol to remove flux and dust.</span><br />
<span>The circuit can now be worked on.</span><br />
</font><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj19LR7m8fGiwPg52bh0pY-dlmpcGapsJ9PV_AgRMMbqD_GQGmDd_bCSFRVtBMZoNnILZ4Ex23U_3K5GsS8DRTzb5RVLqAXYNeEuX43pWDHcNH6zM_3LFLtuZH1gPcdR5wBkEfNFVv6R_Py/s1600/DSC_0992.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><font face="arial"><img border="0" height="112" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj19LR7m8fGiwPg52bh0pY-dlmpcGapsJ9PV_AgRMMbqD_GQGmDd_bCSFRVtBMZoNnILZ4Ex23U_3K5GsS8DRTzb5RVLqAXYNeEuX43pWDHcNH6zM_3LFLtuZH1gPcdR5wBkEfNFVv6R_Py/s1600/DSC_0992.jpg" width="200" /></font></a><font face="arial"><span><br />
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<br />Clean dust from chassis.</span><br />
<span>Clean all pots and sockets with de-oxidiser fluid.</span><br />
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<b><span><font face="arial">Modifications</font></span></b></div>
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<font face="arial"><span>I have largely copied the EVJ "marshall mod" (schematics for which can be found elsewhere). </span><span>After about six hours of changing component values, I found a sound which I was happy with.</span></font></div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjTo6yhtHxMsGKa8IysUg2Fo_7tRuYwGnpQsgfGEHvlB26hSFUBRh8iUI4-fvAdK15qf64kPFPkg7AqPkV0__17LvJMzTbk6PDzi9S_f9V0iHQ6BvlLn59JeQB-wTMjHgNbmXO8q-nIYUUO/s1600/VJHotRod+Schematic+-+Original.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><font face="arial"><img border="0" height="141" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjTo6yhtHxMsGKa8IysUg2Fo_7tRuYwGnpQsgfGEHvlB26hSFUBRh8iUI4-fvAdK15qf64kPFPkg7AqPkV0__17LvJMzTbk6PDzi9S_f9V0iHQ6BvlLn59JeQB-wTMjHgNbmXO8q-nIYUUO/s200/VJHotRod+Schematic+-+Original.jpg" width="200" /></font></a><font face="arial"><span></span><br />
<span><span>Original Circuit</span></span><br />
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<span><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhwlzBnAvJd1LGerD_ZleoA2taZTauSwz5FU8iZ-mDKLakG9DNa2-lneB3jJWicw5ftozE1Ou9s9Hus97T7KAb1B5PbLt-Qj5EPQ8lcniNxX1cjXrCwRfm4K0bzSzeYh_hUR23XrAv-FO-w/s1600/VJHotRod+Schematic+-+LEVY+Modification.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="141" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhwlzBnAvJd1LGerD_ZleoA2taZTauSwz5FU8iZ-mDKLakG9DNa2-lneB3jJWicw5ftozE1Ou9s9Hus97T7KAb1B5PbLt-Qj5EPQ8lcniNxX1cjXrCwRfm4K0bzSzeYh_hUR23XrAv-FO-w/s200/VJHotRod+Schematic+-+LEVY+Modification.jpg" width="200" /></a><span><br /></span></span><br />
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<span><span>Modified Circuit</span></span><br />
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<span>The result was a brighter sounding amplifier, with a well defined low end, and higher gain. Adjusting the controls for low gain settings produces a smooth overdrive, and higher gains ramp up to a broad fuzz sound.</span></font></div>
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<span><font face="arial">A word of caution; the quality of the EVJ circuit board is very poor. Excessive heat will easily lift circuit board pads and traces. Ensure that you use a good heat controlled soldering iron.</font></span></div>
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<span><font face="arial">Lowering R3 will increase input level to the first triode stage. Lowering R6 increases quiescent current through the second triode stage, while lowering C8 and C9 serves to 'tighten' the bass response.</font></span></div>
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<span><font face="arial">Increasing C16 improves bass reproduction of the power pentode.</font></span></div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjUXMS5A6FuosW1aBITg-yKYv6zmbu_yIl8hLQBD4QDxwI5Dlc8GD6ZXkl1eUg_f5UORGc3OuKUVMYpJx8n6YjdtOBYVq4gjJsDMQ_EsDgyQ58J5OqRitR0ZvTlFMfP0EDUVMvIjftvjcTP/s1600/DSC_0994.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><font face="arial"><img border="0" height="112" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjUXMS5A6FuosW1aBITg-yKYv6zmbu_yIl8hLQBD4QDxwI5Dlc8GD6ZXkl1eUg_f5UORGc3OuKUVMYpJx8n6YjdtOBYVq4gjJsDMQ_EsDgyQ58J5OqRitR0ZvTlFMfP0EDUVMvIjftvjcTP/s200/DSC_0994.jpg" width="200" /></font></a><span><font face="arial">The addition of a 1K 1W resistor at the pentode screen will limit current through the amplifier in the case of valve failure. This modification requires cutting a circuit trace, and drilling holes to mount the additional resistor on the top of the circuit board.</font></span></div>
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<font face="arial"><span>I found the reverb on the stock unit to be very thin, and so decided to modify the reverb circuit also. </span><span>Lowering R22 and R25 increases quiescent current through the triode stages, while removing C21 and C22 produces a more linear frequency response.</span></font></div>
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<span><font face="arial">Increasing C18 prevents low frequency rolloff (use ceramic cap due to voltage present).</font></span></div>
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<span><font face="arial">Increasing R27 reduces output of reverb to a more subtle, controllable level.</font></span></div>
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<span><font face="arial"><br />
Details and schematics for the EVJ Hot-Rod <a href="http://tonebuster.org/home/index.php/verstaerker/vjhr/70-vjhr-schem" target="_blank">can be found here</a>.</font></span></div>
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Michael Levyhttp://www.blogger.com/profile/18217504205268410755noreply@blogger.comtag:blogger.com,1999:blog-1840519511821046231.post-729271778832986212014-03-11T21:10:00.010+11:002020-06-19T11:27:50.034+10:00Japanese Toolbox<div class="separator" style="clear: both; text-align: center;"><span style="margin-left: 1em; margin-right: 1em;"><font face="arial"><img border="0" height="460" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjcsTd8HkoElZ6ddCJSiui_Ac21eKANdq9v1L8Pj95Q70I9xD8I0VXnUK3MuwMxU8IbUgwlEfz0NFX0qB1jubnwB2yBGdUlVJzAdpujT2UGOnMbhMp_FJqMxzBg5tQNG7WT3rfnsLarO2xM/w611-h460/LEVYbox1.JPG" width="611" /></font></span></div><div><font face="arial"><span></span></font></div><span><font face="arial">The <a href="http://makezine.com/projects/make-34/japanese-toolbox/">design of this toolbox</a> was published on the MAKE website quite a while ago, and was recently included in a MAKE Magazine publication. A toolbox that I made was chosen to appear in the magazine article.</font></span><div><font face="arial"><br />
</font><div style="text-align: left;"><font face="arial">The toolbox is simple to construct, and is very sturdy. I use this design to transport my tools all the time for work as an AV tech.</font></div></div><div><span><font face="arial"><br /></font></span></div><div><font face="arial"><span>The box should only take a few hours to complete, and can be made on a small budget; a single sheet of plywood will be enough for a large box; Mine is </span>800x400x400mm.<span><br /></span></font><div class="separator" style="clear: both; text-align: center;"><font face="arial"><br /></font></div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhzE7-pCOh_2c1NGsqznvZRS6yY-qfVLe2DXp-AXycGX_iCd1Hqw-RBS1Io4eXv1Sq2AvX_ONRPCmASzm2t3JnjVKHJ88RnOBRTMyHzuedo0xQz8TVgjhEtyh60Vd6XdGxQ7e2pgrXVVehW/s1600/LEVYbox2.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="112" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhzE7-pCOh_2c1NGsqznvZRS6yY-qfVLe2DXp-AXycGX_iCd1Hqw-RBS1Io4eXv1Sq2AvX_ONRPCmASzm2t3JnjVKHJ88RnOBRTMyHzuedo0xQz8TVgjhEtyh60Vd6XdGxQ7e2pgrXVVehW/s1600/LEVYbox2.jpg" width="200" /></font></span></a></div>
<font face="arial"><span>Another, smaller box (500x250x250mm).</span>
<span><br /></span></font></div><div><font face="arial"><br /></font></div><div><font face="arial"><br /></font></div><div><font face="arial"><br /></font></div><div><font face="arial"><br /></font></div><div><font face="arial"><br /></font></div><div><font face="arial"><br /></font></div><div><font face="arial"><br /></font></div><div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhlLDcY28sERCEwMOrP_E4_JzrGwO7GdX_95FVzlCs6BYYaItBTWEf30JcekevWh4FQpepe0yRXTTRo8E7Esc9xtYdFJ2hQ789KPB2VjX9gxbt-SksgXSnDvk3y4ExXrz91C7xTvjZc6mJc/s637/MAKE_LEVY.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><font face="arial"><img border="0" data-original-height="637" data-original-width="448" height="256" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhlLDcY28sERCEwMOrP_E4_JzrGwO7GdX_95FVzlCs6BYYaItBTWEf30JcekevWh4FQpepe0yRXTTRo8E7Esc9xtYdFJ2hQ789KPB2VjX9gxbt-SksgXSnDvk3y4ExXrz91C7xTvjZc6mJc/w180-h256/MAKE_LEVY.jpg" width="180" /></font></a></div><font face="arial">Make magazine article</font></div>Michael Levyhttp://www.blogger.com/profile/18217504205268410755noreply@blogger.comtag:blogger.com,1999:blog-1840519511821046231.post-72597396491955871302013-12-09T22:46:00.002+11:002020-06-19T11:28:09.691+10:00FAB Pedal Multi Effects<div class="separator" style="clear: both; text-align: center;">
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiSnG-gppRwSN7AP7oCNgBrJJEzay-keB9164KXrO9y9BldpFnDoErXmWHCbQHsIlAgP1LJkdAk-r86Tgdw42gk4yvRXpMPPfliwiumLm1HYh4ZfcAxDD7xwI4DZMKDuPDNoVxJFSDtvOoS/s1600/DSC_0466.jpg" style="margin-left: 1em; margin-right: 1em;"><font face="arial"><img border="0" height="351" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiSnG-gppRwSN7AP7oCNgBrJJEzay-keB9164KXrO9y9BldpFnDoErXmWHCbQHsIlAgP1LJkdAk-r86Tgdw42gk4yvRXpMPPfliwiumLm1HYh4ZfcAxDD7xwI4DZMKDuPDNoVxJFSDtvOoS/w625-h351/DSC_0466.jpg" width="625" /></font></a></div>
<font face="arial"><span>This analogue multi effect unit can be made from Danelectro FAB pedals </span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh4ei56QCeoylUX4K5X_WDk5CCbMITq0pBOJg7PqA4H-322tkpLM8Ag7v0Wxy0MYgc9oFWtjWmBgB5uIg0U9g42pXFu4Pa3ULDHM3646tt2EeIpD13JQjvpED4KZiwjyARkkQHQMeIOPMcJ/s1600/danelectro-fab_pedals_001.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><font face="arial"><img border="0" height="160" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh4ei56QCeoylUX4K5X_WDk5CCbMITq0pBOJg7PqA4H-322tkpLM8Ag7v0Wxy0MYgc9oFWtjWmBgB5uIg0U9g42pXFu4Pa3ULDHM3646tt2EeIpD13JQjvpED4KZiwjyARkkQHQMeIOPMcJ/s200/danelectro-fab_pedals_001.jpg" width="200" /></font></a></div>
<font face="arial"><span>Danelectro FAB pedals can be sourced cheaply on ebay. Other parts include press button switches, LEDs, 6.5mm mono jacks, and some hot melt glue.</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgXota1jP-OvtO7YdqDPkQEBFuOyjsA6vMQBCgidHxFGloqTXI7Wno7vp-9jXotzridWdDQbtA1yG34cVvhkXqnUexzKm59wsCkN-SXpNQ_ljPJiL_eQhGf715_VCeWAPTuzEtxmwgBhGP6/s1600/DSC_0380.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><font face="arial"><img border="0" height="112" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgXota1jP-OvtO7YdqDPkQEBFuOyjsA6vMQBCgidHxFGloqTXI7Wno7vp-9jXotzridWdDQbtA1yG34cVvhkXqnUexzKm59wsCkN-SXpNQ_ljPJiL_eQhGf715_VCeWAPTuzEtxmwgBhGP6/s200/DSC_0380.jpg" width="200" /></font></a></div>
<font face="arial"><span>Aluminium sheet was cut to size and squared, then marked and drilled for each of the existing pots on the circuit boards. Press button switches, jacks and power was also drilled.</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhqNrtcJx9JiKQnYe3GLBdtnoFtODMUu7TZu8O_1aBy1EWxyui0CMROJ8LoVV-iup-FSJz-KpRM_0kz-OOxSJ1h-L3MiR7XZSYKoTo486d4ayCXWwUBiUynSEvx-34_3q-3cowpArZqYEMX/s1600/DSC_0459.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><font face="arial"><img border="0" height="112" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhqNrtcJx9JiKQnYe3GLBdtnoFtODMUu7TZu8O_1aBy1EWxyui0CMROJ8LoVV-iup-FSJz-KpRM_0kz-OOxSJ1h-L3MiR7XZSYKoTo486d4ayCXWwUBiUynSEvx-34_3q-3cowpArZqYEMX/s200/DSC_0459.jpg" width="200" /></font></a></div>
<font face="arial"><span>Each circuit board was fixed to the face plate with hot melt glue, then each pedal wired in a chain (output to input of next...).</span><br />
<span>Tinned copper wire was used for the ground connections, to give some rigidity to the rear circuit boards.</span></font></div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiyN7A_Wj7-5UVYMsxmtQ_2KUtjKGErYiFErp-OStwN8n6voi7sN42NQv7XqAPhUw_ALRh2SaJqtcL54lxlw52JZyK1b9sVSMj6n9AvH3pCpbGj1vUS37PhvUmUZHwtrXfTf-cCS3orJqrV/s1600/DSC_0465.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><font face="arial"><img border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiyN7A_Wj7-5UVYMsxmtQ_2KUtjKGErYiFErp-OStwN8n6voi7sN42NQv7XqAPhUw_ALRh2SaJqtcL54lxlw52JZyK1b9sVSMj6n9AvH3pCpbGj1vUS37PhvUmUZHwtrXfTf-cCS3orJqrV/s200/DSC_0465.jpg" width="112" /></font></a></div>
<span><font face="arial">Plywood box was made to suit.</font></span></div>
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Michael Levyhttp://www.blogger.com/profile/18217504205268410755noreply@blogger.comtag:blogger.com,1999:blog-1840519511821046231.post-21932269776041950542013-09-22T20:31:00.005+10:002020-06-19T11:28:40.878+10:00True Bypass / AB Box Circuit<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj-qySGMJTPLGajeV6dJtBtVkkM9VlmQsWSJDUyI2RZkzvLXT2d7n7EYLFZONEy89oNnghfkG-i4ueUbd1NTrbwf04jtDuW0uT3CvFD-g53sv5-7Llpkl4BzkSMvppixK9qywOqF7n2UD28/s1600/DSC_0291.jpg" style="margin-left: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="351" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj-qySGMJTPLGajeV6dJtBtVkkM9VlmQsWSJDUyI2RZkzvLXT2d7n7EYLFZONEy89oNnghfkG-i4ueUbd1NTrbwf04jtDuW0uT3CvFD-g53sv5-7Llpkl4BzkSMvppixK9qywOqF7n2UD28/w625-h351/DSC_0291.jpg" width="625" /></font></span></a></div>
<font face="arial"><span><span>Back to basics; here is a super simple true bypass pedal. </span>It can be used to bypass a chain of effect pedals with one switch, to switch between two sources (eg, two guitars), or to switch between two outputs (eg, an amp and a tuner).</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjDmXrNqCxIA6lblC9HsKy6b2YkXDVUGtZgxLSj3H9zuEJ6QFi5e7NFZWjIR1jiPdQm0nas9zpqc32KajqHDEZwz19sEiAQH3gec_r7pgTG6ohxc-le-EYm74H3KNOJ3W3EUTGfWgXBeMKr/s1600/DSC_0292.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="112" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjDmXrNqCxIA6lblC9HsKy6b2YkXDVUGtZgxLSj3H9zuEJ6QFi5e7NFZWjIR1jiPdQm0nas9zpqc32KajqHDEZwz19sEiAQH3gec_r7pgTG6ohxc-le-EYm74H3KNOJ3W3EUTGfWgXBeMKr/s200/DSC_0292.jpg" width="200" /></font></span></a></div>
<font face="arial"><span> The pedal uses a DPDT foot switch, 4* 6.5mm jacks, and the project should cost ~$25.</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg0sL58W3vnKRK1Fbva-M6WlN3GLkB5zG0ME4ngTWGLaI3qEd4rkDZylC9gR3DKl-QfRdq5I8pm4RO-jPptGxvfY2uP1AhTpQ7SFnuLYo57ofml945oT-HxsgVLwWdwBBxlgHRJNVEm2c_T/s1600/True+Bypass.png" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="158" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg0sL58W3vnKRK1Fbva-M6WlN3GLkB5zG0ME4ngTWGLaI3qEd4rkDZylC9gR3DKl-QfRdq5I8pm4RO-jPptGxvfY2uP1AhTpQ7SFnuLYo57ofml945oT-HxsgVLwWdwBBxlgHRJNVEm2c_T/s200/True+Bypass.png" width="200" /></font></span></a></div>
<span><font face="arial">The project is entirely point-to-point wired.</font></span>Michael Levyhttp://www.blogger.com/profile/18217504205268410755noreply@blogger.comtag:blogger.com,1999:blog-1840519511821046231.post-29389168207544850232013-04-28T16:20:00.005+10:002020-06-19T11:29:30.509+10:00Make MonoBox - Trash speaker<div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial, helvetica, sans-serif; margin-left: 1em; margin-right: 1em;"><img border="0" height="351" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEim-YZ7LWDCU7BLX_En_HlyrcOH_mcCF10m2PLvpCw074oyZ9DiT3dkC0h7QQJbQE_9H-0HArnzUprR2gIv21DtmUmnVn_qfG-GPVfb6e_jC69_x4nHz-FaqWlkee2t4p8ffRrSOl847Kp3/w625-h351/DSC_0137.jpg" width="625" /></span></div><div><span style="font-family: arial, helvetica, sans-serif;"></span></div><div class="separator" style="clear: both; text-align: center;">
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<span style="font-family: arial, helvetica, sans-serif;">Many mix engineers will cross reference a mix through an alternative set of speakers. The concept is that no one out in the real world has a set of studio monitors. This is part of the reason that NS10s and Aurotones are such sought after speakers.</span><div style="text-align: center;"><br /></div>
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<span style="font-family: arial, helvetica, sans-serif;">Make magazine has published a <a href="http://blog.makezine.com/projects/make-34/monobox-powered-speaker-2/" target="_blank">small amplifier circuit based on the LM386 op-amp</a>, which is well suited to use in small form powered speakers. </span><span style="font-family: arial, helvetica, sans-serif;">Unbalanced line level feeds the amplifier, which is powered by a 9V wall adapter.</span></div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEijitG5h-OY5wDikZs_p3o5x-FkE0agGFtk0yaUBF5f33IDtsNLgPICxDUUL7Vee4BIpNBt6u7CvuNHm5CB46RHLL2VNW01QnrRuMVb6i0iu7f_U9nhpSOKlt_yxEqyryrKPKY0YRdpvhSp/s320/DSC_0135.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><span style="clear: left; float: left; font-family: arial, helvetica, sans-serif; margin-bottom: 1em; margin-right: 1em;"></span></a></div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEijitG5h-OY5wDikZs_p3o5x-FkE0agGFtk0yaUBF5f33IDtsNLgPICxDUUL7Vee4BIpNBt6u7CvuNHm5CB46RHLL2VNW01QnrRuMVb6i0iu7f_U9nhpSOKlt_yxEqyryrKPKY0YRdpvhSp/s1600/DSC_0135.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><span style="font-family: arial, helvetica, sans-serif;"><img border="0" height="112" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEijitG5h-OY5wDikZs_p3o5x-FkE0agGFtk0yaUBF5f33IDtsNLgPICxDUUL7Vee4BIpNBt6u7CvuNHm5CB46RHLL2VNW01QnrRuMVb6i0iu7f_U9nhpSOKlt_yxEqyryrKPKY0YRdpvhSp/s1600/DSC_0135.jpg" width="200" /></span></a></div>
<span style="font-family: arial, helvetica, sans-serif;"> Internal Layout</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgdsgZbKP2Bq2hHTCmn5h_S8qC_7CPwbA0TDFcPAmjnTx8fn8oYjyHDEDfDDqy-DgxHGfG-_t4EwWAfbCuCW9ne7R0VR_FMTV6tEzGiIXgHK87MU833k-DxJC03GJM6qQJz8ngNENWr-hrI/s1600/DSC_0136.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><span style="font-family: arial, helvetica, sans-serif;"><img border="0" height="112" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgdsgZbKP2Bq2hHTCmn5h_S8qC_7CPwbA0TDFcPAmjnTx8fn8oYjyHDEDfDDqy-DgxHGfG-_t4EwWAfbCuCW9ne7R0VR_FMTV6tEzGiIXgHK87MU833k-DxJC03GJM6qQJz8ngNENWr-hrI/s1600/DSC_0136.jpg" width="200" /></span></a></div>
<span style="font-family: arial, helvetica, sans-serif;"> Rear Panel</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjgqxcE2Nfd9-4J5kVn_mI5b2CgIw9EzJvGMUlJk5eAjFgaKSarn-mOOVNdlHLTSHrV-J7_DcNSToQSsXH9zsWFVazWtcShqGFFFV9y0VKCDgaCBRnVUF4IuFmPkdSq28NFaWR_npKrq1hC/s1600/MAKE+Monobox+(2).jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><span style="font-family: arial, helvetica, sans-serif;"><img border="0" height="160" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjgqxcE2Nfd9-4J5kVn_mI5b2CgIw9EzJvGMUlJk5eAjFgaKSarn-mOOVNdlHLTSHrV-J7_DcNSToQSsXH9zsWFVazWtcShqGFFFV9y0VKCDgaCBRnVUF4IuFmPkdSq28NFaWR_npKrq1hC/s1600/MAKE+Monobox+(2).jpg" width="200" /></span></a></div>
<span style="font-family: arial, helvetica, sans-serif;"> Veroboard Layout</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEie7QYpR3GNDfDJvgwRhoxX7dG-trOD-GftffFAqrDeg5n7EytCC8EDtvN9XsopWrmZjJaIXaX6N6VF4ZXgItiGmVtXtRAkVR9oZ7JapLGy_71TSm9t2nryi2pJcD7PaZbuAhXx757_eFLJ/s1600/MAKE+Monobox.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><span style="font-family: arial, helvetica, sans-serif;"><img border="0" height="150" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEie7QYpR3GNDfDJvgwRhoxX7dG-trOD-GftffFAqrDeg5n7EytCC8EDtvN9XsopWrmZjJaIXaX6N6VF4ZXgItiGmVtXtRAkVR9oZ7JapLGy_71TSm9t2nryi2pJcD7PaZbuAhXx757_eFLJ/s1600/MAKE+Monobox.jpg" width="200" /></span></a></div>
<span style="font-family: arial, helvetica, sans-serif;">Schematic</span><br />
<span style="font-family: arial, helvetica, sans-serif;">R1 is 10K for line level source. Change to 100R for headphone level source. If using a wall adapter, remember to filter your psu with a 100uF electro cap.</span></div>
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<font face="arial"><img border="0" height="351" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiMRKGu3asUfCU_gchIQocaawIFkBTHFGIvidzNG1b1xinkcRxpfER84QdyeqWDdeaMl2C8g-LaTa7HPOPDhw3VohsCzPw0sHesGpxFzAYGGtmPgiJQCJA3tEb-h3JTmrAir1aw9LCCoJ9P/w625-h351/DSC_0071.jpg" width="625" /></font></div>
<font face="arial"><br /><span>A circuit from Beavis Audio (website now defunct).</span><br />
<span>This is a CMOS multi-waveform noise tone generator which can be used for droning experimental sounds.</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEje3LWLvpYxTtT9HTqarEWBR2bnvibywngvSIgYsCYp_qWT_VdNTYSOWAYHyuWrgDmfO1g7yR-sy3Mdok5i1UADIG1l-CNFrwfumi0qBGQEzxdZvhBYJ5dahaaOXBH4S6tc2b0bbeTxoPCi/s1600/Beavis+Heterodyne+Space+Explorer.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><font face="arial"><img border="0" height="160" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEje3LWLvpYxTtT9HTqarEWBR2bnvibywngvSIgYsCYp_qWT_VdNTYSOWAYHyuWrgDmfO1g7yR-sy3Mdok5i1UADIG1l-CNFrwfumi0qBGQEzxdZvhBYJ5dahaaOXBH4S6tc2b0bbeTxoPCi/s200/Beavis+Heterodyne+Space+Explorer.jpg" width="200" /></font></a></div>
<font face="arial"><span>The chip is capable of six simultaneous waveforms, but I only used four for this project. Veroboard layout:</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjb3bhyDVRbZhqQrpt8rW7X-cdeCVGQ__rnHwL5uUu1XPZiQWM2oCfdLZZN7E0u6j9B-1nX2cIu2m56kgwAevxvC-7CQvh2cOatiZBoq4mTl8GCzObpyi5b8ZJLgiTu6_NRRi8bGXByYZPD/s1600/Simple+PSU+Filter.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><font face="arial"><img border="0" height="160" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjb3bhyDVRbZhqQrpt8rW7X-cdeCVGQ__rnHwL5uUu1XPZiQWM2oCfdLZZN7E0u6j9B-1nX2cIu2m56kgwAevxvC-7CQvh2cOatiZBoq4mTl8GCzObpyi5b8ZJLgiTu6_NRRi8bGXByYZPD/s200/Simple+PSU+Filter.jpg" width="200" /></font></a></div>
<span><font face="arial">Remember to filter your power if using a wall adapter.</font></span><br />
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Michael Levyhttp://www.blogger.com/profile/18217504205268410755noreply@blogger.comtag:blogger.com,1999:blog-1840519511821046231.post-74861058581003377852013-04-13T14:03:00.004+10:002020-06-19T11:30:39.656+10:00Noisy Cricket Amplifier<font face="arial"><br />
</font><div style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgpxblaDITFu6EnmQ18n7b9rYKGoi5AMVBoQLeNwlz0WYOPegAkyXs-igJS9b14oWrcwfFiD0Agvtqy8tU3p53_WDLM5RNR6F4z_OTcWolNp5p_wsm_s_GxFHX-hV-82t0WHzWNbWWlWkXL/s1600/DSC_0009.jpg"><span><font face="arial"><img border="0" height="351" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgpxblaDITFu6EnmQ18n7b9rYKGoi5AMVBoQLeNwlz0WYOPegAkyXs-igJS9b14oWrcwfFiD0Agvtqy8tU3p53_WDLM5RNR6F4z_OTcWolNp5p_wsm_s_GxFHX-hV-82t0WHzWNbWWlWkXL/w625-h351/DSC_0009.jpg" width="625" /></font></span></a></div>
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<font face="arial"><span>The <a href="http://www.beavisaudio.com/projects/NoisyCricket/" target="_blank">Noisy Cricket amplifier</a> from Beavis Audio is one of my favorite circuits, but I always think small form amps like this are never really taken seriously.</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhBkinEycjreR9SHdU0LE0PBhU5pfa5C6ENJQl2de_19vQ0TtifICvC2tjaJM-l24jxyen7v7lVnuz2WHzLwcsK3tIreh8SEqZzvX1ZH__AZw8NHCzyTdIK1klH7GBXJwl4G4vcfhkNZCeB/s1600/DSC_0001.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><font face="arial"><img border="0" height="112" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhBkinEycjreR9SHdU0LE0PBhU5pfa5C6ENJQl2de_19vQ0TtifICvC2tjaJM-l24jxyen7v7lVnuz2WHzLwcsK3tIreh8SEqZzvX1ZH__AZw8NHCzyTdIK1klH7GBXJwl4G4vcfhkNZCeB/s200/DSC_0001.jpg" width="200" /></font></a></div>
<font face="arial"><span>I decided to do some serious over-engineering to present this 1/2 watt amplifier in a large amp format.</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh3ZaiYkQX6vPNo4ZzIYlPE1hILQKI5Hlh3b7I4Ka-wB6Hay7cnvdFYff1E2J9xIuun6nw_-t2MFDtIdTA8fSsGSlH3T630cTUUdWe7nANMWGckpp8tKQf8CYqUEPyd2cfc5B7mqicRaP8R/s1600/Noisy+Cricket+schem.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><font face="arial"><img border="0" data-original-height="439" data-original-width="699" height="125" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh3ZaiYkQX6vPNo4ZzIYlPE1hILQKI5Hlh3b7I4Ka-wB6Hay7cnvdFYff1E2J9xIuun6nw_-t2MFDtIdTA8fSsGSlH3T630cTUUdWe7nANMWGckpp8tKQf8CYqUEPyd2cfc5B7mqicRaP8R/s200/Noisy+Cricket+schem.jpg" width="200" /></font></a></div>
<font face="arial"><span>Original schematic from Beavis Audio (website now defunct)</span>
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<span><font face="arial">I re-designed the circuit layout for turret-board; this has no impact on the sound of the amp, but it sure looks cool.</font></span></div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjJ42k-UaDgAiqKMggvJe8psVUKu86EAacAocraKsw9eEtoU5XQAn-FVOyxr2ZjhtWI_SZ1LCUGB1HVilGMmX0WUE0i-WThDou0PMhbxFwI8cm7q4avO4gekLTNOBCPl0w3Xo0UrkIEugoB/s1600/DSC_0008.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><font face="arial"><img border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjJ42k-UaDgAiqKMggvJe8psVUKu86EAacAocraKsw9eEtoU5XQAn-FVOyxr2ZjhtWI_SZ1LCUGB1HVilGMmX0WUE0i-WThDou0PMhbxFwI8cm7q4avO4gekLTNOBCPl0w3Xo0UrkIEugoB/s200/DSC_0008.jpg" width="112" /></font></a></div>
<span><font face="arial">I think the amplifier looks a lot better in this form, than the tiny project box. It pairs well with my fuzz speaker.</font></span></div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgoTzRThTWWOxfX3bmjj_pQyifK8IEBmF_m4ng3auLP04-dRgJtIeSPUOMr45MN58I0cqA61kWEfPy5ul-8GzFd4UKvqckKnsCwwcAMzHJJSquoWr14cL6KO03kwjmtGz1aiF6Jc5Dp6SUW/s1600/NoisyCricketMarkII_RadioShack_Rev2.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><font face="arial"><img border="0" data-original-height="1600" data-original-width="972" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgoTzRThTWWOxfX3bmjj_pQyifK8IEBmF_m4ng3auLP04-dRgJtIeSPUOMr45MN58I0cqA61kWEfPy5ul-8GzFd4UKvqckKnsCwwcAMzHJJSquoWr14cL6KO03kwjmtGz1aiF6Jc5Dp6SUW/s200/NoisyCricketMarkII_RadioShack_Rev2.jpg" width="121" /></font></a></div>
<span><font face="arial">Here is the original Beavis Audio board layout.</font></span></div>
Michael Levyhttp://www.blogger.com/profile/18217504205268410755noreply@blogger.comtag:blogger.com,1999:blog-1840519511821046231.post-11811380793627303142013-04-13T11:17:00.003+10:002020-06-19T11:32:04.433+10:00Tailed Bridge Guitar<font face="arial"><span><br /></span>
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<div class="p1"><font face="arial"><br /></font></div><div class="p1"><span><font face="arial">Tailed bridge guitar, based on <a href="http://www.hypercustom.com/"><span class="s1">Yuri Landman</span></a><span class="s2">'</span>s strat eraser project. Fender Jazzmaster body design.</font></span></div><div class="p1"><span><font face="arial"><br /></font></span></div><div class="p1">
<span><font face="arial">Tail tuned to 5th harmonic of the neck, with pickup behind the bridge.This makes massive resonance on some frets.</font></span></div>
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<span>Output using switched sockets can be:</span></font></div>
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<span><font face="arial">1 - Guitar only (mono)</font></span></div>
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<span><font face="arial">2 - Guitar and Tail (mono)</font></span></div>
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<span><font face="arial">1+2 - Guitar and Tail (stereo). Plug into two amplifiers.</font></span></div>
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<span>Artwork for pickguard (stolen from) artist and musician<span class="s1"> <a href="http://www.jadfair.org/"><span class="s2">Jad Fair</span></a></span></span></font></div>
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<span><iframe frameborder="no" height="166" scrolling="no" src="https://w.soundcloud.com/player/?url=http%3A%2F%2Fapi.soundcloud.com%2Ftracks%2F87644043" width="100%"></iframe></span></font>Michael Levyhttp://www.blogger.com/profile/18217504205268410755noreply@blogger.comtag:blogger.com,1999:blog-1840519511821046231.post-6992834897036807102012-05-27T21:01:00.004+10:002020-06-19T11:32:31.446+10:00Fuzz Speaker Cabinet<font face="arial"><br />
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<font face="arial"><span>A great fuzz sound can be created by cutting slits in an old speaker cone. This method was popularised by The Kinks (You really got me).</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjTREuDnGZATgm12kwNO3IxzBhF9xVLiT-hyTZJMppvjWylA9-Epe5XRHKyNkg_el8gZGorIoKop6Z2NG3WQXq-WfXcUYwMgBA9CKGVYtVeTzO2BRkDS1vQNT8OU4iJxIdaAemGqWc-kZSP/s1600/DSC_0302.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><font face="arial"><img border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjTREuDnGZATgm12kwNO3IxzBhF9xVLiT-hyTZJMppvjWylA9-Epe5XRHKyNkg_el8gZGorIoKop6Z2NG3WQXq-WfXcUYwMgBA9CKGVYtVeTzO2BRkDS1vQNT8OU4iJxIdaAemGqWc-kZSP/s200/DSC_0302.jpg" width="150" /></font></a></div>
<font face="arial"><span>I have had an old 12" speaker laying in my workshop for a few years, and decided to give this a try.</span><br />
<span>Experiments with the speaker sounded pretty good, so I decided to make a cabinet to house it.</span><br />
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<span><iframe frameborder="no" height="166" scrolling="no" src="https://w.soundcloud.com/player/?url=http%3A%2F%2Fapi.soundcloud.com%2Ftracks%2F48350419" width="100%"></iframe></span></font>Michael Levyhttp://www.blogger.com/profile/18217504205268410755noreply@blogger.comtag:blogger.com,1999:blog-1840519511821046231.post-43511054622516340392011-11-08T23:49:00.002+11:002020-06-19T11:33:23.023+10:009V Panasonic Electret Mic<div class="separator" style="clear: both; text-align: center;">
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<div><span><font face="arial">A great sounding mic can be made for under $20. The Panasonic WM-61A electret capsule (~$5 on ebay) can be modified to be used as recording or reference microphone.</font></span></div><div><span><font face="arial"><br /></font></span></div><div><font face="arial"><span>The mic (which is omni-direcitonal) is phantom powered with a 9V battery. This is the simplest and most noise-free method of powering the mic.</span><br />
<span>The panasonic electret capsule must first be modified, by cutting the trace at the rear of the capsule that connects terminal 2 to ground.</span><br />
<span>The capsule is wired to a coaxial cable, and a sturdy diecast aluminium enclosure houses the circuit, which is point to point wired.</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiV5Ic5UjCJgr7LzyY0j2rVhDTW97iKJyCahKViWsHw1SNAHw-efFT3e4alV092iJ5v7HbcRq1IxVw7ElsdYD_Fqdq8o8eeNBP_KsLBUlk1vsGeFSgoH1fXSp6GUpI0HBowLJFlgbNp2fKR/s1600/LEVY_LinkwitzElectretMic_Schem.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="134" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiV5Ic5UjCJgr7LzyY0j2rVhDTW97iKJyCahKViWsHw1SNAHw-efFT3e4alV092iJ5v7HbcRq1IxVw7ElsdYD_Fqdq8o8eeNBP_KsLBUlk1vsGeFSgoH1fXSp6GUpI0HBowLJFlgbNp2fKR/s1600/LEVY_LinkwitzElectretMic_Schem.jpg" width="200" /></font></span></a></div>
<font face="arial"><span>Schematic</span><br />
<span>The circuit for this mic was taken from <a href="http://www.linkwitzlab.com/sys_test.htm">Linkwitz Lab</a></span><br /></font>
<br /></div>Michael Levyhttp://www.blogger.com/profile/18217504205268410755noreply@blogger.comtag:blogger.com,1999:blog-1840519511821046231.post-78860903147238655382011-10-25T23:31:00.006+11:002020-06-19T11:37:49.464+10:00Reverse DI / Reamping<div class="separator" style="clear: both; text-align: center;">
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<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj5Z_LhgiopxsiKLazZhcGNL39iYTi2A282KaFfabI6f_1CtLEagyLJBeNaCMZrfFkbpkzQiCfsDdDvEbMPNHEtNFef9PfEmPPHyeGDA5QFO4GWdWXYgvXh4MBqSYSPSGZwjbP0IA5WbM9H/s3264/DSC_0108.jpg" style="margin-left: 1em; margin-right: 1em;"><font face="arial"><img border="0" data-original-height="2448" data-original-width="3264" height="375" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj5Z_LhgiopxsiKLazZhcGNL39iYTi2A282KaFfabI6f_1CtLEagyLJBeNaCMZrfFkbpkzQiCfsDdDvEbMPNHEtNFef9PfEmPPHyeGDA5QFO4GWdWXYgvXh4MBqSYSPSGZwjbP0IA5WbM9H/w500-h375/DSC_0108.jpg" width="500" /></font></a></div><div class="separator" style="clear: both; text-align: left;"><font face="arial"><br /></font></div><font face="arial"><span><span>Re-amping is the process of playing a recorded guitar track through a guitar amplifier. The main reason for doing this is to perfect the tone of a recorded guitar track after the recording has taken place.</span></span><br />
<span><span><br /></span><span>Due to the high impedance inputs of all modern guitar amplifiers (anything built after 1980), you can simply connect a line level output of a mixing console to the instrument level input of your amplifier to achieve the desired result (There will be no impedance mis-match, as opamp inputs have >1M input impedance).</span></span><br />
<span><span><br /></span></span><span><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgGE9TOEKR_FByHKw8crPtOxTngU-YPaan_X020ndX5Dz0JOnM_RyzUnp51YVIIa-BpZ8fRuPK3TDHZDui84TFxivZzPqhEpLE8KCmQKiTxtuobGumUv8tqtzZJD1it_zP6DZInAes2R_yw/s2048/LEVY+Reamp.png" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" data-original-height="1486" data-original-width="2048" height="186" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgGE9TOEKR_FByHKw8crPtOxTngU-YPaan_X020ndX5Dz0JOnM_RyzUnp51YVIIa-BpZ8fRuPK3TDHZDui84TFxivZzPqhEpLE8KCmQKiTxtuobGumUv8tqtzZJD1it_zP6DZInAes2R_yw/w256-h186/LEVY+Reamp.png" width="256" /></a></div>This circuit adds a few features that my be useful; The transformer isolates ground of the mixing console and guitar amplifier, and the attenuation pot is purely for convenience.</span></font>Michael Levyhttp://www.blogger.com/profile/18217504205268410755noreply@blogger.comtag:blogger.com,1999:blog-1840519511821046231.post-50581398755354739692011-10-18T00:53:00.002+11:002020-06-19T11:38:14.402+10:00FET Buffer Cable<div style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiViyBGF8Nc39K_RdVvaFj4zvAg70qg1TJk_tGCTBWtFflf7wXtO7lpQYSCy8oI9bYhbloDd5o-o5Ncvwr5l8Q1ITvSsuo23wDZrq2r4dz6iKuo07Lxv-tUNIJeRrX5Hui5U43s8nWP4RTA/s1600/DSC_0096.jpg"><span><font face="arial"><img border="0" height="469" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiViyBGF8Nc39K_RdVvaFj4zvAg70qg1TJk_tGCTBWtFflf7wXtO7lpQYSCy8oI9bYhbloDd5o-o5Ncvwr5l8Q1ITvSsuo23wDZrq2r4dz6iKuo07Lxv-tUNIJeRrX5Hui5U43s8nWP4RTA/w625-h469/DSC_0096.jpg" width="625" /></font></span></a></div>
<font face="arial"><span>This cable houses a FET buffer. This is an impedance matching device that allows guitars and piezo pickups to be plugged directly into microphone preamps. The device is phantom powered (9-48V dc).</span><br />
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<span>This buffer sounds much better than the crappy transformers in cheap passive DI boxes, and it also obtains the full frequency range possible from piezo pickups (without a buffer, piezos have no low end. this is due to impedance mis-match).</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhzsXXPVxx-qarLzp9hQh7AJrCTUWQELwZpDmoZaxweQMxeGE7fH6o6ZGzWVrn8iPKXcGfKzuNqFuMsfdn4eYo63zU4ijkkxKjTkQxeQyqlITdW8x2mfojj4AYvpKLJED0P6itQu6lwI0c5/s1600/plugschematic.gif" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="100" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhzsXXPVxx-qarLzp9hQh7AJrCTUWQELwZpDmoZaxweQMxeGE7fH6o6ZGzWVrn8iPKXcGfKzuNqFuMsfdn4eYo63zU4ijkkxKjTkQxeQyqlITdW8x2mfojj4AYvpKLJED0P6itQu6lwI0c5/s200/plugschematic.gif" width="200" /></font></span></a></div>
<span><font face="arial">The buffer was designed by J. Donald Tillman, and the <a href="http://www.till.com/articles/PreampCable/index.html">plans can be found here</a>.</font></span>Michael Levyhttp://www.blogger.com/profile/18217504205268410755noreply@blogger.comtag:blogger.com,1999:blog-1840519511821046231.post-50429556782664597182011-06-01T19:05:00.008+10:002020-06-19T11:40:58.998+10:00Behringer ADA8000 Problem - Output Auto Mute "Feature"<div class="separator" style="clear: both; text-align: center;">
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<font face="arial"><img border="0" height="189" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjcy-Qv9puzes0sBoQ1UptevrL5kCk_MBPg2o7Ljdhqj6PWh0eOxwZ574fbuJ_2ONR8UqNHWjt0BoUNliLtnlPsUX-mvW6h2TTRG8DgJ9ErbMLK2O3Bp5qggncyvk3BzAITsplwwpBqlQew/w625-h189/ada8000_lrg.jpg" width="625" /></font></div>
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<br /><span>The ADA 8000 takes a while (0.5 second) to output any audio after you press play. The digital to analogue converters automatically mute audio after a period of digital silence, and take a while to switch back on. This is frustrating if you are using this device for intermittent output eg; a metronome / click track for a drummer.</span><br />
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<span>How to fix this:</span><br />
<span>You need a constant noise signal to keep the D/A converter from automatically muting; the signal can be inaudibly low, and will still keep the converters from muting in 'digital silence'.</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhyYCOhhMOQqhGhJM7bbhYSVeQwSQ2bH6NI72XQY2K3WDjZXbEjHj09AdeBV8bmMj7PQ4_kbNFCrAx0PVX2jqNl02vwYkveVf89HK8UexFfNCvwYuqwbaHqgq31wkHQ_cVKSVAnVrX1Miqz/s1600/capture1.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="160" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhyYCOhhMOQqhGhJM7bbhYSVeQwSQ2bH6NI72XQY2K3WDjZXbEjHj09AdeBV8bmMj7PQ4_kbNFCrAx0PVX2jqNl02vwYkveVf89HK8UexFfNCvwYuqwbaHqgq31wkHQ_cVKSVAnVrX1Miqz/s200/capture1.jpg" width="200" /></font></span></a></div>
<span><font face="arial">Use a dither plugin on it's lowest setting on each of the ADA8000 output channels.<br /></font></span>
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Michael Levyhttp://www.blogger.com/profile/18217504205268410755noreply@blogger.comtag:blogger.com,1999:blog-1840519511821046231.post-16345472942033022812011-05-04T15:03:00.003+10:002020-06-19T11:43:01.672+10:00Kick drum microphone stand.<font face="arial"><span><br /></span>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj4uNByoNphUCqkP22CEl-IKINLqJlA0n9Xz85M1mwRkeFxP5fHitmS64AdazEfGmF_cSVZxZVaNIZDKKbYQv-9t41flguUE-V9h36g5c8P9gwDRRFAbxZWTeurbN01qIK7ShVknWl1-e6X/s1600/DSC_0139.jpg"><span><font face="arial"><img border="0" height="469" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj4uNByoNphUCqkP22CEl-IKINLqJlA0n9Xz85M1mwRkeFxP5fHitmS64AdazEfGmF_cSVZxZVaNIZDKKbYQv-9t41flguUE-V9h36g5c8P9gwDRRFAbxZWTeurbN01qIK7ShVknWl1-e6X/w625-h469/DSC_0139.jpg" width="625" /></font></span></a></div>
<font face="arial"><span>An effective kick drum mic stand can be made from a reglar mic stand, at a fraction of the cost of a production model.</span><br />
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<font face="arial"><span>The cheap mic stand was disassembled, and the length of the main telescopic tubes shortened.</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiPXRLG2RInLSBANvx1F81SvC5Fzbw-44xbD6v0a_zMAUB1eTvGuMTS6KfS90_sIvERFKj2Xyy1Y31wZnTcSZh1v9bZrktbEBQYcF3BjAWKNXEmR_bBZw33t3kZINTdOdefaZzSAedqBMtI/s1600/DSC_0140.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><span><font face="arial"><img border="0" height="150" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiPXRLG2RInLSBANvx1F81SvC5Fzbw-44xbD6v0a_zMAUB1eTvGuMTS6KfS90_sIvERFKj2Xyy1Y31wZnTcSZh1v9bZrktbEBQYcF3BjAWKNXEmR_bBZw33t3kZINTdOdefaZzSAedqBMtI/s200/DSC_0140.jpg" width="200" /></font></span></a></div>
<font face="arial"><span>The stand has several advantages over regular kick mic stands:</span><br />
<span>The boom is longer than regular kick mic stands, so it's easier to close mic the batter head. The boom can also be detached to easily mic a resonant head.</span><br />
<span>The feet are longer, so the stand is more stable and can hold a heavier mic.</span></font>Michael Levyhttp://www.blogger.com/profile/18217504205268410755noreply@blogger.com