Revibe Tank Impedance Tweak?

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zeppenwolf
Junior tube assistant
Posts: 1
(2/13/04 8:18 pm)
 Revibe Tank Impedance Tweak?
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 How much would be involved, if it's possible, to tweak the revibe circuit to accept a tank with an input impedance of either 150 or possibly 170 or possibly 190 ohms?

Eden
 
jc
I only work on Fender's
Posts: 678
(2/16/04 6:40 pm)
 Re: Revibe Tank Impedance Tweak?
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 It's strange that no one has comments so I guess I will give it a shot.

You will need a different output transformer to drive that tank. Currently you use a single ended champ transformer. This expects a primary impedence in the 7k - 10k ohm range and drives a 4 ohm load. Now you need one that will drive a 150 - 190 ohm load.

Why do you want to drive a different tank?
 
zeppenwolf
Junior tube assistant
Posts: 2
(2/17/04 1:39 am)
 Re: subject
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 : It's strange that no one has comments so I guess I will give it a shot.

I appreciate it.

: You will need a different output transformer to drive that tank.

Bummer.

:primary impedence in the 7k - 10k ohm range and drives a 4 ohm load. Now you need one that will drive a 150 - 190 ohm load.

Ah well. It might not matter, but do you understand why the Weber version uses the 4AB tank but the Hoffman uses the 9AB? Or why the Weber has an extra R16, 150ohms from tank input to ground?

: Why do you want to drive a different tank?

 
Because I'm a mad yet cheap scientist who wants to leverage the 4BB I already own, (part of a Blues DeVille). Perhaps I am going against the wind, and should instead attempt to fit a 9AB into my BdV. I'm a wee bit unhappy with the sound, but I would be attempting to overhaul the driving/receiving circuit before any thought of tank replacement (w/ or w/o impedance change).

For reference: accu-type, in, out, from:


4BB3C1B                150ohms        2k25ohms (Blues DeVille)
9AB3C1B                10ohms        2k75ohms (Hoffman)
4AB3C1B                8ohms        2k25ohms (Weber)


Eden
 
EL34  
I got your parts right here.
Posts: 2254
(2/19/04 11:26 am)

  Re: subject
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 4AB3C1B and 9AB3C1B are intercahngeable, they are not different animals.

It would be cheaper to buy the correct tank than to alter an amp to use the tank you have.
Plus you are not assured it will sound good or work properly.
 
 
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