1969 Fender Twin Reverb Question

[mojomike]

I all I have a 69 Fender twin reverb . The Reverb in this amp sounds good until it trail out then it seems to flutter as it fades out and If I play the guitar muting the strings so you can hear more of the reverb it really flutters , it sounds more like a cheap digital reverb .
Any ideas?
Thanks mike...

[ampgeek]

I would start by trying known good tubes in V3 (12AT7) and V4 (7025) if you haven't already.

These are the driver and recovery sections of the reverb circuit.

A 12AX7 can be substituted for the 7025.

Good luck!
Dave O.

[billyz]

It could also be the Tank. Look for loose send and return coils and loose spring joints where they are crimped together in the middle. I sometimes use a tooth pick and super glue to tighten the coils where they enclose the steel laminations, Super glue also works to secure the spring joint crip clamp.

I prefer the sound of medium decay 3 spring pans anyway, so if it is not the 12at7 , you might just replace the pan.

[mojomike]

Thanks for the input I have not tryed the tubes yet but will tonight . As far as the reverb tank I did try one from one of my other twin reverbs and did the same thing so I sure its not the tank ...
Thanks Mike...

[rfgordon]

The long, unshielded leads going to/from the reverb knob can couple signal into the tone stack wiring. Also, the long leads from the tone caps on the board to the tone pots can cause parascitic oscillation. If you move the tone caps/slope resistor from the board to the backs of the tone pots, you'll probably cure the problem, and get rid of almost two feet of unshielded grid wire in the process.