For this amplifier I used a amplifier board from a tv. The circuit drawings can be found here: Circuit right, Circuit Left, Pcb.
This amplifier needs a DC voltage of 33V. To create this voltage I used a transformer from an old printer, it delivers 21VAC (50VA). I've put a rectifier and some caps after the transformer. The case is recycled from an old vcr.
I wanted a volume control with buttons, so I made this circuit that generates analogue voltages with PWM.
This experimental pcb is not really reliable, so I made an etched pcb of it. When building it in I was a bit to enthusiast so I forgot to take pictures. However I do have the print-layout (which contains a fault at the pull-down resistors). Download pcb lay-out.
As you can see, I left 1 voltage regulator of the board. This is because I found a 15V regulator on the amplifier pcb.