Every now and then I get asked about adding reverb, and here’s how one customer tackled it.
“Please find attached photos of my WF-55 with reverb. I’ll post these on the music electronics forum in a few days when I have more time. I might also wait til I’ve tweaked it a little.
“It uses a small sub-chassis attached to the WF-55’s main chassis, with an ECL82 valve to drive the reverb and recover the signal.
“I decided to put both high-voltage wires through one hole, the signal in/out through another and the heater pair through a third. Probably ought to fit a bypass switch on the reverb? Might be useful to fully switch it out the circuit (not just ground the reverb send). I’m guessing I’ll not recover a lot of the gain with the reverb circuit in. I’d hoped the triode and pentode stages would make up all the lost gain through the reverb tank.”