What can cause spring reverb tank to fail?

[H Chandler]

I have an amp in again that I repaired recently. It had a break in the little wire that attaches the transducer to the input rca connector. I was able to resolder it and it seemed fine.

Now, it's got the same problem again. This time I've just subbed in a new tank and it works fine again. But I'm worried that there might be something that's taking out the little wire. Like perhaps an intermittently shorting reverb transformer.

Perhaps I should change the reverb transformer too?

Is there anything else I should be looking for?

All comments welcome.

Thanks,

Howard

[52 Bill]

Like perhaps an intermittently shorting reverb transformer.

Perhaps I should change the reverb transformer too?

No, I can't think of any failure mode of the reverb transformer that would cause the tank wires to break, without causing problems with the amp circuitry itself.

Does the amp get moved a lot? Any kind of bouncing will cause the tank wires to flex. How old is the tank?

Those small tank wires are notorious for breaking. The tank gets bounced around and the wire fatigues from being flexed, and eventually breaks.

The first time you fixed it, you fixed the first wire to break, maybe this time a different wire has broken. Sometimes when you inspect the wires, you can see the ends are starting to fray and you can re-strip and resolder the ends where they connect to the RCA jacks as preventive maintenence.

Sometimes the wires break in the middle of their length, at the point where they are held down under the small metal clip. These breaks are nearly impossible to see before they happen.

The worst case is when one of the internal coil wires breaks. You can replace the coil, but it will be easier at that point to just replace the entire tank.

[H Chandler]

[QUOTE=52 Bill;56276]

Does the amp get moved a lot? Any kind of bouncing will cause the tank wires to flex. How old is the tank?

Well, my guess is it gets moved around a lot since this amp belongs to a very active professional musician. And with all the potholes in New Orleans, bouncing is just a part of getting anywhere. I know one guy who has a bunch of pillows in his trunk for carrying his amp to gigs.

I don't think the owner of this amp is nearly as careful. The first time I worked on this amp, it had no sound at all. The cause? The speaker wire was broken at the speaker end! Probably from using the amp as a suitcase.

The tank is as old as the amp, which is a Holland built around the turn of the century.

Which reminds me to ask again. Does anyone know where Mr. Holland is these days?

Thanks

Howard

[jrfrond]

In the old days, many reverb pans had locks. They are still available as an OEM feature from Accutronics, but no one specs them. All of the excess movement during transportation kills the pan at these weak points.

Before I install a new pan, I reinforce the wires are the jack and in the Molex connector on the coil with a couple of dabs of hot glue, to dampen vibration and excess movement in these key area. So far, so good.

[Paul P]

When I had my reverb pan made by Accutronics earlier this year I asked for
the locking feature. I was told by Accutronics that locking devices have not
been available for twenty years. You'd think it'd be time they took the option
out of their charts.

Paul P

[H Chandler]

Has anyone devised any cheap tricks for devising a lock?

The trouble is, I'd probably have the guy forget to lock it anyway.

[jrfrond]

When I had my reverb pan made by Accutronics earlier this year I asked for
the locking feature. I was told by Accutronics that locking devices have not
been available for twenty years. You'd think it'd be time they took the option
out of their charts.

Paul P

Well there ya go, no locks.

EXCELLENT way to sell more pans.

[Enzo]

Well, I can count on a couple times every year, someone buys an old AMpeg, comes in with it to have me fix the reverb, and I flip the brake off, and it works. "There is a reverb lock on these things??"

Over the decades, I can't really say I have seen higher failure rates in amps without the brake over those with it. I replace more of the little short pans than anything, and frankly I see more of those dead in store stock than I do in customer work. That is new from the box repairs. The pan didn't have time to shake itself apart.

[jrfrond]

.....I replace more of the little short pans than anything, and frankly I see more of those dead in store stock than I do in customer work. That is new from the box repairs. The pan didn't have time to shake itself apart.

Same here, and I could never figure out why. The ratio as compared to the long pans is staggering!