I wonder if anyone knovs what reverb unit is should be in a Earth Sound Revival 2 12 combo. I have bought this old amp and like the sound but i think that the decay time om the reverb is to long, the reverb unit in my amp is a accutronics marked 4F B2 B1 B. Is there someone who knows if this is the right reverb unit for this amp.

I hope you could understand my english, I'm from Sweden so my english are not the best

/Bosse

Your Earth Sound Revival amp is basically a copy of a Fender Twin Reverb, that I do know. Whether that's the right reverb can or not, I don't know. I don't have a schematic for it, or I could tell more about it.

Your 4FB2B1B has a medium decay time, as indicated by the fourth digit, "2". The Twin Reverb's tank has a long decay time of "3", which you certainly wouldn't want if "2" is too long for you already! Plus, the input impedance and ground scheme of the unit used in the Fender is different from yours.

I don't think Accutronics makes a shorter length direct equivalent reverb can for yours, which would have a shorter sounding decay time even though also rated at "2". However, they may be able to help you in some way, if you'd give them a detailed e-mail. Cal, the tech at Accutronics, is a very nice fellow. I know I've called on him more than once before when I ran into problems with repairing reverb sections. His e-mail address:

cal@soundenhancements.com

One more thing you may try: If the tube driving the reverb is a 12AX7, try a 12AT7 or 5751 instead. If it's a 12AT7, then try a 12AY7 or 12AV7, or even as far down in gain as a 12AU7. That will drive the tank less hard, and may or may not solve your problem. It will not be operating optimally, but it may be a cheap fix for your problem.

Thermionic

What I understand by asking on other forums is that this amp are a copy of Pevey amps from the same time period. This amp shall have solidstate preamp but it have a tube poweramp. So I don't think I could change any tubes in the driving stage for the reverb. I shall try to email that guy at Accutronics to hear what he have for ideas of this problem. I got a schematic but there are not any specifications on the reverb tank on the schematic and I'm not so good to read the schemaitc so I can figure out what tank it should be by reading it, if you will can I email the schematic to you.

/Bo

Thermionic

/Bo