Replacement Springs For Reverb Tanks

[hpdonat]

Does anyone know of a place that sells just the springs for reverb tanks?

[The Dude]

I don't know where you can buy just springs. I keep a pile of bad tanks to salvage parts from. Maybe you could find someone with a bad tank pull the springs out of?

[hpdonat]

Yep, I've kept an eye out for sure.

[Axtman]

Unless your reverb tank is very rare or unusual, why bother repairing it when replacement tanks are cheap?

https://www.tubesandmore.com/products/reverb_tanks

I to have a box of old broken reverb tanks. I am not sure why I keep them.

[g1]

You can't do anything with the springs if the cores are broken out of the transducers. Even so, I don't think you can buy them anymore. I save them from scrap tanks but it's silly because the springs never go without the cores.

[Helmholtz]

That "core" is actually the rotor of the transducer (either used as motor or as generator).
It's a little ferrite magnet attached to the suspension wire and has a hook for the spring on its other end.
The suspension wire is also critical. Needs to be thin, tough and flexible.
Was originally made of Beryllium-Copper alloy. Not sure if that's still allowed.
The springs in an Accutronics tank are not all the same.
Springs having different delay times are mixed to get a more even response.

https://patents.google.com/patent/US3106610A/en

[Tom Phillips]

A really long time ago replacement spring kits were available from the manufacturer. The cost of the kit was something like 50% or more of the cost of a new tank. These kits are no longer available and as already mentioned in this thread, the break on modern tanks usually destroys the transducer connection such that there is no way to connect a replacement spring.

I too save old tanks. However, to date, I have never used the parts to repair a broken tank. One time I tried to remove a transducer wire with the ferrite cylinder by un-soldering the attachment at the end of the copper tube. That attempt was a failure because the heat made a gooey mess out of the damper material that surrounds the transducer hook wire.

[Chuck H]

The springs in an Accutronics tank are not all the same.

+1 to all points above but especially THIS^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Different springs are used in the same tank to create the multiple echo effect. A tank made with random or all the same springs wouldn't be very satisfying. Not to mention that even if you did want to experiment with a pile of salvaged springs you would probably damage tiny motor parts before you hit on a combination that worked.

And I don't think the springs are as carefully selected or possibly even of the same quality as they once were because I sometimes buy three tanks for any reverb amp I build. One typically sounds so bad or is so sensitive microphonically that I know I can't use it in any application and gets thrown out. The other two are always different, but sound at least ok. Because I do it this way I often have another tank on hand if I haven't used it somewhere else already. So now I have two or three selected tanks to choose from and one usually has a good vibe with the amp I'm working on.

This is, of course, bad news for anyone that just wants to buy a good tank and put it in because IMHE there's no guarantee that a new tank will be useful at all. Much less sound good.

EDIT: And, FWIW, I have actually tried to alter the echo/tone of bad sounding tanks by carefully changing springs. I would snip the spring I wanted to change near the transducer leaving enough to carefully bent a hook into the remaining fragment so I could install/remove salvaged springs with hooks bent at those ends. Results weren't often satisfying. I've also tried altering tanks by either stretching out a single coil on a spring to reduce tension or snipping a few coils out to increase tension. Also not usually satisfying. I've certainly ruined several more tanks than I've ever saved doing these things. But it didn't matter because these would have been tanks that sounded bad anyway.