The Day The Reverb Died - Resurrected! :D

[Blackburn]

The tank in my '66 Princeton seems to have gone to reverb heaven, but I'm curious if there are things I can try that may resurrect it. I swapped a spare modern tank I have here and it works fine while the original doesn't. Anyone have any suggestions? Maybe reflow the joints inside the unit? Hit it with a bag of nickels or dip it in some ice cream? The readings I get with my meter (R) are consistent with the modern tank, so I'm a bit confused as to what the deal may be here.

I'll be on the lookout for an original on the Bay, or if someone has one here that they're willing to sell, if I can't fix it.

DK

[martin manning]

Measure DC resistance on the input and output. If either side is open, look for a broken wire. You may be able to resurrect it.

[Blackburn]

Martin, thanks for the reply. I measure 183R from the output tip to the case and from the input tip to the case is about 1R. The Mojo reads 200R from the output tip to case and 1R from the input.

[martin manning]

Oops, I guess you said as much in the opener. Try measuring it from the far end of the cables. Maybe there is poor contact between plug and jack.

[Blackburn]

Did that too. That's the first thing I suspected when this thing happened. Checked the continuity and these are good. The readings I posted were read from the tip of each cable.

[martin manning]

Is any signal coming through at all?

[pops]

If you look inside there are very tiny wires from the springs to the transducer and may have broken, sometimes you can very carefully solder these. There are better sounding tanks out there tho so maybe you can repair it, but save it for the originality and use the other tank.

[martin manning]

Since the input and output DC resistances are not infinite and reasonable, a broken wire doesn't seem likely.

[Blackburn]

Haven't checked that out, Martin. I'll give it a go and see. I'll also hook it up and give it a whack or two and see if it registers through the speaker and alerts me to which side may be bad.

If it comes to that, I will, Pops. Thanks for the response.

[billyz]

I think you should have about 10 ohms on the one side , 1 ohm sounds too low. Might have a shorted coil.

[Stevem]

Your pan is fine, but many times on Fenders I have had no verb due to the 12at7 being cracked open and ready for garbage can!
Yup! no fuses blew or anything, just no verb!
While you have the pan out you can take steps to insure that it does not go south from the norm of failed wire connections.
Get some silicone glue and place a blob on each wire solder point on each rca jack and then a nice blob where the wires go into each little coil, these are the points where 99% of the pan failures take place!

[martin manning]

Still a mystery. Blackburn reports (above) that the reverb works with a different pan, and the I/O DCR's are very close to the new pan as measured.

[Firestorm]

On Fender tanks, the input tip should read open to the case (input jack is not grounded) so if you read 1R to the case, there may be a short. Have you inspected the inside?

[billyz]

I just measured one I was working on, original 1965 vibrolux reverb. It was 193 ohm and 1.8 ohms. on the inside of the tank green wire to black wire.
Reverb was not working , turned out to be corrosion on the jacks. Cleaned em up and now shes good.

[Blackburn]

Thanks guys for all the helpful responses, guys. I'm happy to report that the tank is working again! I'm sure it was simply a continuity issue like Billy reported with that Vibrolux, and likely the jacks on the tank itself. I suppose it was the fiddling on my bench that wore down enough corrosion. Next time I'll just go straight for some cleaner and start from there.