BFDR Vibrato Not Working... What Could It Be?

[lakehaus]

The only symptom I can state is this: It worked one day, then it didn't.

I checked my Rev/Vib footswitch and cable with a multi-meter... it seems to function fine. The reverb responds to the switch, and I tried plugging the reverb cable into the vibrato plug - no go.

My vibrato doesn't work at all anymore. There was no noise, smoke, or otherwise. I can't even pinpoint the event cuz I don't use vibrato much anyway.

I'm not a technician, but am curious if there may be something simple a "tube changer" like me can address, or is this clearly a case for a seasoned tech?

Thanks for any advice.

[sliberty]

Maybe the roach died (the LDR). I had to replace on in a Bandmaster recently to get the trem working.

[Wayne]

If you're a "tube changer", then I would start with what you know - change the tube with a known good one. You might get lucky!

W

[lakehaus]

If you're a "tube changer", then I would start with what you know - change the tube with a known good one. You might get lucky!

W

Thanks - Here's how lame I am... there's a tube for that? I don't think the tube chart specifies. I'll do some research on that..

[jjman]

Try switching the 1st small tube (on the end) with the 5th tube from that same end. The 1st is the Normal channel preamp (which is working, right?) and the 5th is the trem tube.

Both tubes should say "7025" and/or "12ax7" on them. (same thing)

If that doesn't fix it you should verify that the pedal is ok.

[lakehaus]

I tried the tube swap (thanks jjman), with neg result. The tubes glow in that socket. I double checked the footswitch with the multi-tester - unless I'm missing something - it works. I also switched leads-to-input from the switch to the amp (rev/vib). When I did this, the vib switch worked fine for the reverb.

Someone mentioned "the roach died"... ???

[sliberty]

Since you tried the footswitch and the tube, the next step is probably to replace the roach (LDR). This is a job for an amp tech. If you are handy with amps, it's not hard at all, but if not, you'll need someone to obtain the right part, unsolder the old one, and solder in the new one.

[lakehaus]

Since you tried the footswitch and the tube, the next step is probably to replace the roach (LDR). This is a job for an amp tech. If you are handy with amps, it's not hard at all, but if not, you'll need someone to obtain the right part, unsolder the old one, and solder in the new one.

Thanks sliberty. I'll check into the details of this repair. Maybe I can handle it... I did a 3 prong conversion to my SFVC and Bassman... and a pot change out on my Marshall... hmmmm

[sliberty]

http://www.tubesandmore.com

Part # R-VOP1020

[billyz]

Check all your grounds. especially the one on the rca jack. I have seen very few bug that were actually bad. You should be able to test it . one side is a simple filament and should read almost like a short. What are the voltage readings? Does it light ? it if does not oscillate check or replace the three caps. I usually only need to does this to change the range or pulse. Short the RCA jack to ground , does it work ?

[lakehaus]

Check all your grounds. especially the one on the rca jack. I have seen very few bug that were actually bad. You should be able to test it . one side is a simple filament and should read almost like a short. What are the voltage readings? Does it light ? it if does not oscillate check or replace the three caps. I usually only need to does this to change the range or pulse. Short the RCA jack to ground , does it work ?

I appreciate the advice, however it exceeds my simple abilities... I am pretty much resolved to living without tremolo, or bringing the amp to my local Alpha Mucic tech.