Ampeg B-22-X reverb tank and tremolo problem...

[CB Amp]

Hello,

I'm trying to restore an Ampeg B-22-X (from 1969/70).
The reverb tank is faulty, but I don't find the good reference for a replacement model. This is a capacitor driven circuit.
I see the "Type C" model at Fliptops, but they don't say anything about the B-22-X. Does anyone know the reference of the tank of the B-22-X ?

And I also think that the tremolo module is dead. The one proposed by Fliptops is very expensive. Do you know how to build one ?...

Thank you.

[Phil_S]

Assuming it is a Gibbs tank, you can contact Accutronics, the company that took over Gibbs. Generally, they have records and can tell you. You can do this on their website via email. They also explain the tank numbering system. Can't help you with the tremolo, as I am unfamiliar.

[Firestorm]

The Type C tank has a 200 ohm input impedance and I believe Ampeg usually grounded the input and output. Hard to find anywhere but Fliptops (although you can get away with a Type B with a 150 ohm input impedance and ground any insulated connection yourself).

I have no idea how to homebrew a VM1 reverb mdule 'cause I've never been willing to cut one open to reverse engineer it. You could email Gregg Hopkins at Vintage Amp Restoration and see what he charges for a VM1 replacement.

EDIT -- Oh, before you spring for a new trem module, replace the .047 caps in the oscillator circuit. They were only rated for 250v and may have gone leaky by now. A leaky cap in a phase loop will shut it down. Make sure the tube is good and strong, too. You need a lot of gain to make the oscillator work.

[Phil_S]

Here's the link you need. tubesandmore.com is cheaper than buying direct if they have the one you need.
http://www.accutronicsreverb.com/prodspec.htm

[stubbyfex]

Hello!
I've had good results by using the pan with the highest input impedance for Ampegs. There is no reverb transformer that takes the hi-z from the driver tube and changes it to low-z to drive the pan. If I recall the accutronics number was 4fb3c1b. It was the highest input-z that they made.
The tremolo is just a lamp and a photocell inside the box. If you can measure the voltage going to the box, then you can find a lamp that would work on that voltage. The Fender assembly has a neon lamp and a photocell. It might work, at least the photocell would be OK.
Good luck with your repair.

[CB Amp]

Thanks a lot for all your help.
There was a faulty cap in the tremolo circuit, hopefully the VM1 is ok.
But it has got 2 photocells. It makes 2 different types of effect : a tremolo and a vibrato, which is really funny, a kind of soft flanger... something that get close to the UniVive multi stages phaser, great idea...