I was given some Pass Camp Amp Class A boards by a mate a few years ago, I built them up and put them in a box. Recently I thought I would try them with some lashed up heatsinks and fans to keep them cool. I was so inpressed with them for such little money that I had to do the job properly. The popular way is to power them is with a regulated SMPS at either 19 or 24vdc (for 24v an additional resistor needs to be added).

As I don't like spending money I utilised an existing linear unregulated supply giving approx 25vdc used for a JLH 10w Class A years ago in a tatty case with large enough heatsinks so thought I would transplant the ACA into there and make it look pretty.

Below is the result. The interesting thing is that you can in a small way tailor the sound to suit you by tweaking the DC bias with the pots on the boards.

The Cambridge Pre below is to have remote volume control of a sub.