Hi everybody,
I am new to this forum and I want to share my experience with the rebuild of yet another ST70. I bought this one on ebay not so long ago. It was in a descent state but I stripped the entire amp and started all over again. It gave my the fun of building a ST70 myself.
What I don’t like about the ST70 is the PCB on top. So I decided to eliminate the PCB by point-to-point wiring underneath. I had a cover made from chrome steel plate for the ‘PCB gap’ and gave it ventilation slots similar to the ones near the EL34’s, just for aesthetics.
The chassis is still original. That is the advantage of an empty chassis; it gives you room for a thorough cleaning. After that I polished it with brass-polish and finished it of with a layer of Turtle wax.
I did not alter the schematics except for the mono/stereo switch that I left out. I also placed a new transformer (230V AC in my country) and a new multicap 80-40-30-20. Of course I replaced al the resistors and capacitors. I reused the tube sockets, which I found in a perfect state
The amplifier lost al its hum and sounds crystal clear. I am very pleased with the results.
Pictures of my amplifier:
http://www.mijnalbum.nl/Album-J4WJS6CU-Foto's-in-Emmeloord-Foto's-van-Voorwerpen.html
Your comment, please.