My Vibro Champ Reverb

[ntasher]

With no info available on the web - I had to do it on my own. So I took pictures of the process and finally got around to posting it for the sake of others who might want to try out.
Result is amazing, by the way.
Nir
http://sites.google.com/site/ntasher/vibro-champ-reverb

[darrellcheng]

Great Job! Lots of useful information there. Looks beautiful

[Ben N]

Nice job, looks good. T'were me, I'd have put the reverb driver/recovery, possibly with its own power supply, in a separate small chassis, which looks like it would fit on the floor alongside the reverb pan. That way, at most I'd need a small grometted hole in the chassis for send & receive shielded cables.

[ntasher]

Actually - that was my initial direction - having a seperate chassis to hold the extra components. But then I realized that it would require the mixed wet/dry signal to travel back to the main chassis and that signal is pretty wimpy until amplified by the second half of V1. That would have caused noise and hum problems that I didn't want. Plus there is that clean look to it when it's all in one chassis... I know some die hard vintage freaks see that as unholy but we are here to play, mod and enjoy, right?

[Ben N]

Hey, it's your amp, so whatever works for you, right? My personal unorthodoxy is that I would not hesitate to use a mosfet source follower to buffer the signal before sending it on its way.

[ntasher]

Adding a MOSFET stage would have required a seperate, low voltage, clean supply and the entire circuit would have had to go on a piece of breadboard... and that would have ruined the "clean" look of the amp. Or not... hmmm... next time.

[GibsonLover]

Use high voltage MOSFET

Google for RG Keen's MOSFET FOLLIES paper, and you'll see it drops right into any triode stage. I'm doing the same thing for the oscillator/PI stage on a custom Fender brown vibe circuit, just before the triode mixer stage.