deluxe reverb with reverb making loud sound above 3

[ukulele kid]

My silver face reverb makes a loud high pitched screeching noise above 3 on its setting. Does any one know a fix for this. Also I dont have the foot switch for the vibrato and was wandering how I can make it work without it. I want to fix it so I can get more than $400 that was offered by a guy that came over and played through it. I have it for sale at $650. Thanks

[ukulele kid]

If I can fix my amp I just may keep it if it sounds good. It has made this noise ever since I bought it 14 years ago. I paid $650

[pdf64]

Does the reverb work at levels below 3?
The cables to the reverb tank plug into the back panel. If they are unplugged, does the squealing stop?
The vibrato just needs an RCA / Phono plug with the hot and ground shorted together, to get it working.

[ukulele kid]

yes it still makes the noise when I unplug them . Also I tried the rca twist the leads together trick on the vibrato and I got a ticking that I could speed up or slow down with the speed knob

[ukulele kid]

The reverb below 3 is very little if any.

[ukulele kid]

I guess $400 is not a bad offer.

[wagdog]

The fix could be something simple and inexpensive, but if you don't know your way around the innards of an amp I strongly suggest you take it to someone who does.

So if you don't have the chops to fix the amp, you're going to have to pay someone to do it... and that is likely to run into $150-$300 depending on what's wrong with it. Add that to the $400, and it's probably not a bad offer.

[jrfrond]

It's possible that you might have an extremely microphonic reverb drive tube and/or it might be a 12AX7 instead of the proper 12AT7. If the oscillation is occurring without the reverb pan plugged in, then it is something on the reverb recovery side.

I agree that if you don't know your way around a guitar amp's innards, you shouldn't be troubleshooting oddball problems.

[pdf64]

Try removing the tube from V1 and fitting it to the V4 slot.

I got a ticking that I could speed up or slow down with the speed knob

Was there any tremolo effect on the guitar sound when the intensity control was turned up?

[ukulele kid]

when you say v1 is that the first covered tube from the left?

[pdf64]

Yes

[ukulele kid]

I tried the intensity control turned up and did not work, however when I turned up the reverb I got the horrible screech like normal, but after that the tremolo started working but with a faint ticking.

[ukulele kid]

I pulled the v1 . Its a 12at7, v2 12ax7a, v3 12ax7a, v4 12at7, v5 12ax7a, v6 7025

[ukulele kid]

Mistake made on post above. corrections are...... I pulled the v6 . Its a 12at7, v5 12ax7a, v4 12ax7a, v3 12at7, v2 12ax7a, v1 7025

[pdf64]

V1 is the furthest from the rectifier / power tubes, see http://www.kcanostubes.com/content/f...ecommendations

If a different, presumably good tube from V1 hasn't fixed it, the next most likely cause of the screech is a bad cathode bypass cap on the V4 cathodes; not something you should attempt without sufficient competence, but should be a cheap job for a tech, a $1 cap and minimum bench fee ($50?).
Of course the cause of the screech may be something else.
It may also benefit from the tremolo opto-isolator ($10 part) replacing, as that could have an intermittant open circuit, and also some of them can tick worse than others; or the cause may be poor lead dress. A couple of other fixes are also available but bear in mind that it's difficult to totally eliminate; it's a stage amp and in that application a higher level of background noise is tolerable.