Reverb and vibrato not working on my Twin

Allen Peterson · Post by **Allen Peterson** » 11 Dec 2005 6:26 am

The reverb and vibrato are not working at all on my 65 Twin Reissue. Any ideas on why? I've tried taking the footswitch in and out but to no avail. If I move the cabinet when the amp is on, I can hear the spring. Help!!

Jack Stoner · Post by **Jack Stoner** » 11 Dec 2005 7:02 am

The Vibrato may be a bad tube. Same way with the Reverb - also check the connectors on the rear of the amp for the reverb.

The Tremolo tube is V5, a 12AX7

The driver tube for the reverb is V3, 12AT7.
The input (return from the reverb) is 1/2 of V4(a), a 7025 but since you can get "noise" from the Reverb it may be the driver tube. <font size="1" color="#8e236b"><p align="center">[This message was edited by Jack Stoner on 11 December 2005 at 07:07 AM.]</p></FONT>

Jerry Erickson · Post by **Jerry Erickson** » 11 Dec 2005 8:40 am

If you're hearing the reverb "boing", but are unable to get signal into the reverb, I would suspect a broken wire on the input of the reverb tank. They're small,brittle wires and prone to breaking. Pull your reverb tank out and check out the wires that go from the input jack to the little transformer in the tank.
The vibrato could be the capacitors in the oscillator circuit, the optoisolator or possibly one of the pots .

Allen Peterson · Post by **Allen Peterson** » 11 Dec 2005 10:11 am

Thanks for the input. I will check these things out. It is strange that both the reverb and vibrato went out at the same time. Makes me think it has something to do with the circuitry. I'm no electrician so I will probably end up taking this amp to a specialist.