reverb tank in the circuit

connie_mack
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reverb tank in the circuit

Postby connie_mack » Thu Jun 10, 2010 7:00 pm

hi folks,
i have been bitten by the electronics bug lately and have been trying to understand dc circuitry better. i am reading through an instructional book now but am not up to speed on most of the basics yet. a long way to go, i'm sure. but am very interested in how the reverb tank works in an amplifier. if someone has a schematic they could share showing where/ how the tank is hooked up to an amp or preamp i would appreciate it. or even a good description. thanks in advance.

am also looking for other good instructional books on circuitry. thanks

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Dennisthe Menace
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Re: reverb tank in the circuit

Postby Dennisthe Menace » Thu Jun 10, 2010 7:02 pm

That would be "Mr. Reverb" Danny (Dubtrub), who built one from scratch ;) ......
make the Mos' of it, choose the 'rite stuff.
.........Owner of 9 Mosrites...
.....proud owner and documented:
1963 "the Ventures" Model s/n #0038
http://www.thevintagerockproject.com/

Mr. Bill
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Re: reverb tank in the circuit

Postby Mr. Bill » Fri Jun 11, 2010 12:49 pm

Spring Reverb has a history dating back to Hammond Organ Tone Cabinets in the 40's and 50's. In fact the term for spring reverb was often Hammond Reverb.

The original tanks were actually designed to hook up to an amp's speaker output. Then the delayed signal from the springs was sent back to the amp's input where it was mixed with the non-delayed signal for reverb.

Fender Reverb amps basically have a small tube power amp section with an output transformer that is used only to drive the reverb tank. Then there is a simple tube circuit that amplifies the delayed signal from the tank and sends it to the main power amp circuit. The standalone units have the drive, return and mixer circuits all in a separate box.

So to answer your question, the guitar signal first goes into a preamp circuit that boosts the signal to a level that the rest of the amp can work with. Then it will go to some sort of tone control/shaping circuit and then to another preamp for some more boost. From here it will go to the power amplifier and it is usually here that the signal is also sent to the reverb drive circuit. This is just a circuit that will boost the signal high enough to drive the reverb springs. The signal from the reverb tank is then amplified by another gain stage who;s output is then sent to the amp's power amp.

If you search the web you'll find hundreds of Fender reverb combo schematics out there. If you find one you can follow the circuitry that I described through each of the stages.

As for books, try and find the Jack Darr Guitar Amp troubleshooting book. This is an old book that covers a lot of basic stuff, and has been published on a few websites.

connie_mack
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Re: reverb tank in the circuit

Postby connie_mack » Sat Jun 12, 2010 4:47 pm

hey, thanks mr. bill

excellent description. and advice. i didn't realize that schematics were so readily available on the web, and fer sure, i found one for my twin 65' re-issue but also some for original reverb units by fender. so i'm getting a better idea of what's going on. i'm also trying to finalize a download of the book. i prefer hard copies but that's @25 bucks right now and that's @25 bucks too much.

so many questions......


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