Testing Reverb tank

[JoeK]

If you had a suspect faulty reverb tank and can hear the springs on the recovery side bumping around could you swap the rca leads around at either end (preferably tank end since the cable proved Ok) and then bump the tank to see if you get anything and prove the send side transducer? Or do I need another coffee? Are the transducers at each end different besides the earthing?

[The Dude]

The input and output transducers are different impedance so in is in and out is out. Normal fault condition is open because the wires break either at the jack or at the transducer. You can check continuity at the RCA jacks that go into the amp. This checks both the cable and the transducer. If one of them is open, pull the tank and check cables and transducer to see which is at fault.

[52 Bill]

The input and output transducers are different impedance so in is in and out is out. Normal fault condition is open because the wires break either at the jack or at the transducer. You can check continuity at the RCA jacks that go into the amp. This checks both the cable and the transducer. If one of them is open, pull the tank and check cables and transducer to see which is at fault.

While this is true for many tube amps, a lot of amps that use solid state circuits for the reverb will have tanks that have input and output impedances that are not so far apart. I find that in these cases the tanks can be plugged in backwards to test the tanks.

Frankly, I've used that test on Fender tube amps for years. Even with the huge mis-match of impedances, you can still hear the tank springs rattle when the tank is plugged in backwards. This only really works when you shake the tank.

And to answer the other question, the two transducers are mounted differently because the laminated core structures are different. One is optimized for a pickup and the other end as a driver.