Make MonoBox - Trash speaker

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.

Make magazine has published a small amplifier circuit based on the LM386 op-amp, which is well suited to use in small form powered speakers. Unbalanced line level feeds the amplifier, which is powered by a 9V wall adapter.

 Internal Layout

 Rear Panel

 Veroboard Layout

Schematic
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.