Audio Amplifier

This part of the build is now complete and works well. Testing with a PSU, resulted in a lot of mains hum but, using a quality bench power supply it worked very well. I have mounted some 4"/10cm speakers (Maplin part no. L20AT), one on either side of the chassis to provide decent stereo sound and volume. These have grilles to go over them.

I bought a 3W stereo amplifier module from Maplin .

It requires a 3-10Vdc (I've gone for 9V) power supply so I've built a small daughter board with an onboard 9V regulator. The 12V power supply to this is switched via the I/O board to save power.

It is fed from the PC line out.