Checking earth requirement for replacement reverb tank

noisepolluter

A little while ago I bought a TAD reverb tank as an upgrade for the Accutronics in my mid-00’s deluxe reverb (guessing the age - it has an opto trem circuit).

The effect itself was an improvement - deeper and warmer - but there was a clearly audible hum which got louder as the reverb was turned up. I tried turning the tank 180 degrees and even moving it out of the cab but no joy.

I did match the part number with the existing tank - ended up sending it back but have read that tanks can be earthed differently even with the same part number. Is there a way I can check the existing tank to be sure of which one to order?

jpfamps

They should not be earthed differently; the 5th character of the part code indicates the grounding.

A	Input Grounded/Output Grounded
B	Input Grounded/Output Insulated
C	Input Insulated/Output Grounded
D	Input Insulated/Output Insulated
E	No Outer Channel

However, the TAD tanks are all made with no grounding connections, and the ground connections are made by applying solder to solder pads on a PCB to which the RCA sockets are mounted; thus you can modify the ground to suit your needs.

See image below.

There is NO grounding on this terminal.

I've occasionally had TAD tanks with no grounding where there should be.

noisepolluter

Interesting.
So by looking at the corresponding pcb  on the accutronics and replicating the connections on the TAD it would solve the problem? Or is it not that easy?

(or is there another brand of tank I could go for which has the grounding and still sounds better than the accutronics?)

jpfamps

noisepolluter said:

Interesting.
So by looking at the corresponding pcb  on the accutronics and replicating the connections on the TAD it would solve the problem? Or is it not that easy?

(or is there another brand of tank I could go for which has the grounding and still sounds better than the accutronics?)

There is no PCB on an Accutronics!

The TAD should have the correct grounding, as indicated by the 5th character in the tank code; however I have had tanks where there is no grounding at all.

To add grounding you will need a solder the copper pads on the PCB together: a trivial job.

noisepolluter

Ah ok, thanks. That seems less of a stab in the dark now.