UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - My first single ended stereo amplifier build

Gabe001 · 3rd Feb 2023, 5:42 pm

Hi Richard

The circuit is shown in the last picture in post 2. It's very minimalistic. It's a bit hard to read component values but happy to answer questions. What is doesn't show is the arrangement to elevate the heaters but that's just a voltage divider. EL34 anodes are at 340v, just to give you an idea of voltages.

I personally like the signal input at the front right next to the volume control, to keep the signal wires short, but she wanted all wires out of sight. Not too fussed about on/off switch but putting this at the front means that the mains primary crosses the width of the amp twice.

The general layout could be improved, I agree. If I build this for myself again I'd have the valves in a 'square' configuration with the el34s behind, next to the OPTs, the 6sn7s/6sl7s in front, and the choke next to the mains transformer. I wasn't aware of the chokes magnetic coupling potential as I had never used one before -or rather I was but underestimated the effect.

3rd Feb 2023, 5:42 pm	#10
Gabe001 Octode Join Date: Oct 2019 Location: Stockport, Greater Manchester, UK. Posts: 1,639	Re: My first single ended stereo amplifier build Hi Richard The circuit is shown in the last picture in post 2. It's very minimalistic. It's a bit hard to read component values but happy to answer questions. What is doesn't show is the arrangement to elevate the heaters but that's just a voltage divider. EL34 anodes are at 340v, just to give you an idea of voltages. I personally like the signal input at the front right next to the volume control, to keep the signal wires short, but she wanted all wires out of sight. Not too fussed about on/off switch but putting this at the front means that the mains primary crosses the width of the amp twice. The general layout could be improved, I agree. If I build this for myself again I'd have the valves in a 'square' configuration with the el34s behind, next to the OPTs, the 6sn7s/6sl7s in front, and the choke next to the mains transformer. I wasn't aware of the chokes magnetic coupling potential as I had never used one before -or rather I was but underestimated the effect.