Super Reverb tremolo issues

[andyjazz]

This is a '71 Super Reverb. The tremolo was ticking and the amp just needed a general "once over." I replaced the frog and the ticking was even more pronounced. After going through the Fender service bulletin about the "clicking" issues I got it to cease. Simply by moving/wire-tying wires around. Apparently there are RF issues involved that can be remedied by fairly crude methods.

Anyway, tremolo sounds great now, only problem is it doesn't come on right away at fire up. Turn the amp on (With the tremolo footswitch connected) push the switch - nothing. Futz around with it awhile (Unplug the footswitch from the amp, plug it back in) the goddamned thing works! I've tried different footswitches - same effect. I'm wondering if anyone has an idea whats going on here. Ever heard of such a thing before? Any reply is welcome.

[Jazz P Bass]

Sounds to me like one of the oscillator caps.
Or the tube itself.

[andyjazz]

thanks JazzP. Yeah, we tried different tubes and a replaced one of the caps in the oscillator circuit. It just looked old and suspect and I had the amp apart, the soldering iron warm so I figured I'd give it a try. I'm going to pull the amp apart and take a closer look at the caps in that circuit. Maybe I'll try some different tubes again. I've been thinking it has to be something with a cap charging and then not discharging efficiently. Once the amp "warms up" the tremolo sounds great.

[MWJB]

What happens when you disconnect the footswitch & use a shorted RCA plug/small crocodile clip to do the switching?

[andyjazz]

The switch is not the problem. Once the amp warms up the tremolo switches off and on normally. There is something in the circuit that isn't allowing ground switching to happen (The tremolo operates by lifting ground - near as I can tell) and the caps in the circuit are supposed to be discharging V once ground is lifted (Or closed) This is what I've been able to come up with. I'll be putting on my detective cap to see if I can find which cap is faulty.