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The 1992 Reissue of the original '65 Twin Reverb. Different from the older model, the reissue is built with a printed circuit board and 1/4 inch footswitch phone jacks. This model features blackface cosmetics and 12'' Jensen speakers.

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The reverb no longer works how can this be fixed?

The amp has been stored in a damp basement and as a result the reverb no longer works.

Also the pots make a lot of loud crackle noises when turned up/down and there is a constant loud humming when switched on.

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This is a tube amp with about 400VDC available on the B+, you could easily kill yourself trying to service this amp if you don't know what you are doing and follow high voltage safe working guidelines. If you haven't given up yet, make sure you discharge the power supply filter caps before doing anything else. If you have any question at all regarding the previous statements, just give up and take it to a qualified technician.

You should be able to find a suitable schematic diagram online - try el34world.com.

Drain the power supply filter caps and lube the pots with "Lock Ease". The solvent will clean the pots, while the graphite powder fills in microscopic voids in the resistance path. If any pots are still noisy, replace them.

Next, to diagnose the reverb... you can see if the driver tube and transformer are ok by just connecting an 8ohm speaker in place of the reverb tank "in" and playing a few notes. If you get no noise there, focus on V3 (12at7) and T1 .

If you do get noise there, reconnect the reverb tank input and attach the reverb tank output to a spare practice amp, or a phono input on a stereo, see if you get sound out of the tank.

If the tank is OK, and the driver side is OK, and you are sure the cables to and from the tank are fine, then try replacing V4 (12ax7).

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This is so important I am going to copy from Noah Ackerman.

"This is a tube amp with about 400VDC available on the B+, you could easily kill yourself trying to service this amp if you don't know what you are doing and follow high voltage safe working guidelines. If you haven't given up yet, make sure you discharge the power supply filter caps before doing anything else. If you have any question at all regarding the previous statements, just give up and take it to a qualified technician.

Drain the power supply filter caps"!!! All his troubleshooting is spot on, but with it being so old I would just change all the electrolytic capacitors they only have max 20 year lifespan the hum is bad caps problem and no signal is a coupling cap that tube amps have lots.

I use Craig Laboratories DeoxIT www.caig.com D100L, D5 spray if I remember correctly there is reverb out jacks and the switch contacts could be dirty use the D5.

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D A Wilgrove will be eternally grateful.
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