Twin reverb tremolo problem

Bandmaster, Bassman, Champ, Concert, Deluxe, Harvard, Princeton, Pro, Super, Tremolux, Twin, Vibrasonic, Vibrolux, Vibroverb and others

Twin reverb tremolo problem

Postby strangedays on Tue Mar 01, 2016 1:10 pm

Hi everyone,i've just bought a 76 twin reverb with jbl and i noticed that the trmolo intensity lacks of volume.I mean, even with the intensity control set on 10, the tremolo is weak and sounds like the intensity is set up on 2/3.It doesn't seems to affects the volume of the amp,and the speed control works properly.
I've tried to change the tube on V5 ,the caps of the tremolo section but nothing has changed.the LDR Optoisolator inside produces light and varies speed as you move the speed control but i wonder if it needs to be replaced anyway.Or maybe could be a bad resistor,or the filter caps(It still has the originals and they must be replaced soon).
Any suggestion would be apprecciated.
Thans a lot.
Gabriele.
strangedays
Court Jester
 
Posts: 83
Joined: Mon Sep 01, 2008 10:04 am

Re: Twin reverb tremolo problem

Postby eolon on Tue Mar 01, 2016 5:14 pm

It sounds like the optoisolator is weak. This may be caused by light leaking into the bug, so try it in the dark and see if it improves. You can also put black RTV on both ends to seal light out. The bug is cheap and easy to replace if it is weak. I see them on e-Bay for $5 - $10.

Hope this helps.

e
eolon
Peasant
 
Posts: 28
Joined: Mon Sep 05, 2011 12:55 am
Location: Ohio

Re: Twin reverb tremolo problem

Postby eolon on Tue Mar 01, 2016 5:55 pm

eolon
Peasant
 
Posts: 28
Joined: Mon Sep 05, 2011 12:55 am
Location: Ohio

Re: Twin reverb tremolo problem

Postby pdf64 on Tue Mar 01, 2016 6:09 pm

Even cheaper, as the neon is working, replacement of just the opto resistor should fix it.
These are reported to work well https://www.tubesandmore.com/products/R-VPC01
To get an even deeper trem effect, a super bright LED can be used instead of the neon, see http://ampgarage.com/forum/viewtopic.ph ... c&start=16
My band:-http://www.youtube.com/user/RedwingBand
pdf64
Knight
 
Posts: 1243
Joined: Thu Dec 14, 2006 9:55 am
Location: Staffordshire UK

Re: Twin reverb tremolo problem

Postby strangedays on Tue Mar 01, 2016 7:05 pm

Thanks a lot for replies.I've just order the ldr.I'll let you know as soon as i've installed it.
Cheers,
Gabriele.
strangedays
Court Jester
 
Posts: 83
Joined: Mon Sep 01, 2008 10:04 am


Return to Fender

Who is online

Users browsing this forum: No registered users and 3 guests