30-6 Prototype
This is the amplifier that started it all over ten years ago! It’s the first AC30 clone that I ever built. There have been over 350 since, but this one is still in my possession, and I don’t think I’ll ever sell it. These pictures were taken when it was brand new – it’s gained a slight patina over the years which in my opinion is not un-attractive.
This amp was built using the power and output transformers from a 1972 Birch-Stolec AC30 donor amplifier (PCB construction) that had seen better days, and a new chassis which I had specially manufactured from my own CAD drawings. The tagstrips, valve bases, and other small parts were new, and the voltage selector, fuse holder and indicator light came out of the spare parts bin. Control panel was from a very early six-input amplifier, and is more of a dull oxblood colour than the more familiar ‘candy’ red panels you see.
At the time, I didn’t know where to get the correct diameter solid core wire for the pre-amp valve-base connections, so I used tinned copper wire covered with coloured heat-shrink sleeving! Very time consuming but it got the job done, and looks good as you can see.
I seem to remember that the amp powered up first time with no problems and it has worked perfectly ever since. Quite a relief, since this was only the second amplifier I had ever made from scratch, and I’d never tackled a project as involved as this before. I didn’t have a variac, so it was a case of plug it in, switch it on, and hope for the best!
This amplifier dispels the myth that Stolec transformers are in any way inferior to the earlier Haddon, Albion, Woden or Parmeko types (although later in the seventies, Stolec did stop putting 5v windings in their power transformers). I would confidently put these transformers up against anything being made today.
It sounds stunning, by the way!
I hope you find the pictures interesting.
Steve
