ticking tremolo in a SF Twin Reverb

[JC@]

I can't get rid of the tremolo ticking on this fender.
I just serviced a 135W that had no ticking at all, but with this one none of the cap to ground or cap across the 10M resistor tricks work.

I tried changing the point where the tremolo tube's cathode resistor/bypass cap conects to ground. No success.

Moving a bit the cables around the tremolo circuit doesn't help.
What else could I try?
Or: is there somethig truly drastic, apart pulling the tube out, to avoid this ticking?

[Tom Phillips]

There are some additional ticking debug tips at:
http://www.geofex.com/ampdbug/vibrato.htm
Good luck. I'd be interested to know if one of the additional tips solves your problem.
Tom

[JC@]

No luck. I still don't see any change.

[Mark Black]

Just curious - are you using the footswitch?

Mark

[MWJB]

There's a copy of a Fender service update in Torres' book about curing ticking vibrato's. I'll check it out tonight and let you know tomorrow, unless anyone has access in the meantime?

[JC@]

Just curious - are you using the footswitch?

Mark

No. I jumper the conector with a short clip lead.

*********

MWJB, I think I found a short transcription in a forum about Fender's Service Bulletin number 9.
When the cap tip fails, then a different lead dressing is needed.
The amp is dead quiet now except for that ticking noise.

[nico.verduin]

have you tried the 22nF cap from the 10 meg resistor/bulb to ground? That usually is sufficient is my experience

[JC@]

Yes that the first thing I tried.
Now I'm ready to give up.
Going to clean the tube socket and replace the optocoupler, and if that doesn't make any difference I'll give up.

[JC@]

Funny. I plugged my mp3 to the amp to see how horrible it will sound, and there was no tick-tick at all.
Back with the signal generator, and the ticking was there.

So?

[wizard333]

I posted something similar on the Vox thread below, but in addition to the cap thing, try twisting the wires that go to each side of your vibrato tube, and move the wires to the vibrato controls away from the channel 2 pots (they are almost always routed right under those pots and right against the leads from channel 2, bad idea) . If you've already done that then not sure; thats always worked for me.

[JC@]

Sorry for the delay in answering, but I had a terrible computer crash: software and hardware crash.

About the ticking, I finally!! solved it changing the neon bulb in the homemade LDR.

I later read this:
http://en.wikipedia.org/wiki/Neon_lamp