What's SSD Amp's I hear you ask?
Well that's simple, they are your transistor or chip amplifiers,
eg: Solid State Device Amplifiers.
I first started building, transistor amp in about 1976. It was when I was studding at Havering Tech College. (at the annexe in Harold hill).
The main thing I built was a mobile 'Disco' rig. it was all the rage then.
The pre amps with tone controls and mixers was the easy bit it was all ways the power amp that was the problem. Mainly getting hold of the right components, from hobby shops, (this was pre maplins shops time. as the only shops I know of was Henries radio shop in Edgeware Road London).
Many thanks to my Brother, as he was working in London, at this time and he had to keep going in to Henerys radio shop to get the stuff for me.
We had fun with the power supply as we kept blowing the rectifying diodes, as we could not get the correct working voltage ones.
The pre amps were based around op-amps if I remember correctly. (sadly I could not find any circuit diagram's for them, and the rig I think may of ended up in Ireland, with one of my school mates).
But I did find some of my drawings for my early attempts of discrete transistor circuits.