The D-12/24 module is a class-D stereo amplifier. It only needs a single voltage between 20 and 30 Volt DC. It has a mute connection thereby giving the option of very low power consumption when not in use.

The input sensitivity is about 1 Volt, so it can be driven directly from a CD-player. For other sources a pre-amplifier (with an amplification of 10 dB or more) is needed. The input impedance is 50 kOhm and at the output it may be loaded with an 8 or 4 Ohm loudspeaker system.

The circuit has built-in protection for overload and a too high temperature. The protection automatically switches on again after the problem is solved.

We advise you to use a good power supply with a transformer giving 18 - 22 Volt AC and a power of 50 Watts or more.

This is the simpliest supply to be used. Components needed:

T1 = 2 x 18-22 Volt - 50 VA

D1, D2 = 1N5401 or 1N5402

C1 = 10.000 µF - 35 Volt

C2 = 4.700 µF - 35 Volt

R5 = 1 Ohm - 3 Watt

R6 = 2,2 kOhm

Of course it's also possible to use a transformer with a single secundary winding and a bridge rectifier.

Fuse = 2 A slow blow