Other Amps

hey Fender circuit dudes


I know just enough to be dangerous... I freely admit.

Last summer a friend built me something along the lines of the Rivera-era Champ II... 12 watts, maybe Princeton power. Solid state rectifier. It was built on a Vibro Champ chassis. Looks and sounds great although a few more tone tweaks are going to be made. It's going thru a C10R.

So I was wondering if a Fender reverb circuit could be added (stuffed) on. Not much room left on this chassis. Would need a pan (would have to be short 10" one -- do they sound any good?) another tube.. (or is it two?) and a driver transformer-- I think those are little guys like a choke. If this were possible I would sacrifice the dogmeat master volume this thing has, no prob there.

So why go thru all this when you can just stick a $75 used Holy Grail on top and have pretty good reverb..(although it gets pretty crashy past halfway up). Not sure, really -- I just like pushing the envelope with Tedious and Demented Projects, I think. I think the answer is no -- not enough room -- but still would like to know what the assembled Council of Experts thinks.


It has been done.


You need to remember that a spring reverb is based on phonograph technology. The tank has two piezo phono cartridges, one to send, the ore to receive, and the circuit is just a small 1 watt amp to drive it, and a phonograph circuit for the receive end. As Powdog says, it's been done.


Now I am getting ideas.. . are there any opinions about short vs. long reverb tanks. Everyone remembers the so called "beautiful girl' short reverb tanks of the 70s. Someone said the shorties have gotten better tho. One guy is swearing by these ones that come from China.


You have to add two tubes and a transformer to do the Fender circuit. You can use a short, 3-spring MOD pan with decent results. I have one in my Champ. It could also be done with one tube and no transformer by someone really clevor.
BTW, the phono cartridge reverb was only on 60's Voxes and the less expensive Farfisa organs. It doesn't work very well...only slightly better than the Danelecto crystal-in-adhesive tape-stuck between spring coils. You could also mount two tubes & a transformer in a separate little box screwed to the bottome of the chassis, or to the inside of the cabinet. If your amp has a push-pull phase splitter, you can return the Reverb thought the other side of the splitter, but that won't work with a Cathodyne splitter like a Princeton.


Doug Hoffman’s site has a good thread on adding a “one tube reverb” circuit. Never done it, can’t vouch for how good it sounds.


Screw a pan on the side and control it with a VanAmps Solemate or Solemate Jr.


Always wanted to shoehorn one of these into a dry amp. Self contained two tube reverb unit atop a 17” Gibbs tank. Even came with a cool knob wired in.


Organ Mate was of course used in organs... have seen them them there. Dano reverb was the worst, even tho otherwise the amps were pretty good sounding.

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