Traynor YGM-1 trem clicking

[Stratosaurus46]

I've got a late-60s/early-70s YGM-1 Guitar Mate 1-12 combo. When the amp is on, and idling, there is an audible clicking sound which varies with changes in the 'Speed' setting, even with the 'Intensity' at minimum. I was told there is a fix available with a diode/cap configuration, and that it's available online somewhere, but I have yet to find it. Then again, I'm not anywhere near the end of the intertubes.

That being said, if anyone has encountered and solved this problem, I'd appreciate any info. Thanks in advance.

I had to re-register -- forgot my old password and hadn't informed the PTB about a new email addy. Duuuuuuuuuuuuh

[Chuck H]

I must not be up on the history of this problem. Is this really common in these amps? Can you supply a schematic? I can't imagine they left the manufacturer doing this. Maybe a bad jack switch ground or an oxidized chassis bolt ground? Did a new tube get plugged in? What about a leaky coupling cap blasting pulses onto another circuit because the filters are old and of higher impedance?

[Jazz P Bass]

Is there a footswitch to turn the tremelo off?

Some of these older Trem do that ticking noise.

[Stratosaurus46]

Unfortunately, the amp is at a friend's place, about 200 miles away. I thought it might be the fact that the amp requires the foot-switch for the trem to be connected. I know several Fender models must have a switch to completely shut off the trem. I hadn't played it for a couple years 'fore I loaned it out. I thought that there was a mod that involved a diode/jumper change, but haven't been able to find it. The schematic is in the amp, of course. Guess I'll have to drive up and get it.

[Stratosaurus46]

I thought that might be case, Jazz. I know that's true about some Fenders, 'cuz it's happened to me in the past. I had heard that there was a diode/jumper change that was 'sposed to cure it, but haven't been able to find it.

Thanks!

[Enzo]

You have it backwards, most old fenders require a footswitch to turn the tremolo ON. No FS, no trem. On the bench, a clip wire across the FS jack turns the trem on.

[Mick Bailey]

Is yours the reverb model? - if it is, does turning down the reverb kill the noise? If so, change the reverb recovery tube grid resistor from 1M to 470K and add a 1.5K grid stopper right on pin 7.

[g1]

schematic here:
http://music-electronics-forum.com/a...-schematic.pdf

[Chuck H]

Well I don't see anything about the schem that should cause ticking. But a schematic doesn't tell the whole story either. I think good filters and changing a couple of ground leads could fix this. With a circuit like this, ticking would indicate that some parameter is changing abruptly and affecting a source that can make itself audible. Even if it means it affects some other circuit. Decoupling and grounds are going to be critical. Keep the oscillator, the power amp and the power supply separate from the preamp and PI ground node and make sure the filters aren't presenting a high ESR (or impedance?, new speak?) to the decoupling process.

[Mick Bailey]

It's usually the reverb recovery tube that picks up noise from the trem circuit. I've fixed a few with the resistor changes.