very strange amp noise-Tremo,Wally et al

Stan Martin · October 9th, 2006, 09:27 PM

I've owned tube amps forever and this one's a puzzler.
I have a mid 60's BF Twin. The other day I had it warming up for a while and when I took it off standby, there was a noise that sounded like air being squeezed out of a balloon. I put it back on standby, waited a few minutes and turned it back on. The sound was gone. Great an intermittent problem.
Anyway this happened one more time.
Is this a tube or component problem? Is it a gasey/leaky vacuum on the power tubes?

Tremo · October 10th, 2006, 01:56 AM

Could be a tube on it's way south. Could be a plate load resistor.

Intermittent problems are a nightmare to track down. Next time it does it, start tweaking knobs to see if any of them have any effect on the noise, that will give you an idea where in the amp the noise is coming from.

Tim Swartz · October 10th, 2006, 12:32 PM

I've had a few Fenders that generated siren/squeal sounds in which the problem was the cathode cap on the reverb return.

Wally · October 10th, 2006, 12:34 PM

Ditto what Tremo says. I would have both channels set up to play...volumes and tones up to a normal setting. When the problem occurs, shut down one channel at a time....maybe you can at least get an idea where to start looking.

Stan Martin · October 11th, 2006, 08:04 AM

I still haven't found it, but at least I have a starting point.

October 9th, 2006, 09:27 PM	#1 (permalink)
Stan Martin Tele-Holic Join Date: Mar 2003 Location: Pepperell Posts: 810	very strange amp noise-Tremo,Wally et al I've owned tube amps forever and this one's a puzzler. I have a mid 60's BF Twin. The other day I had it warming up for a while and when I took it off standby, there was a noise that sounded like air being squeezed out of a balloon. I put it back on standby, waited a few minutes and turned it back on. The sound was gone. Great an intermittent problem. Anyway this happened one more time. Is this a tube or component problem? Is it a gasey/leaky vacuum on the power tubes?

October 10th, 2006, 12:32 PM	#3 (permalink)
Tim Swartz Tele-Afflicted Join Date: Mar 2003 Location: Michigan - Tweenst the Great Lakes Posts: 1,887	I've had a few Fenders that generated siren/squeal sounds in which the problem was the cathode cap on the reverb return. __________________

October 11th, 2006, 08:04 AM	#5 (permalink)
Stan Martin Tele-Holic Join Date: Mar 2003 Location: Pepperell Posts: 810	Thanks Guy's I still haven't found it, but at least I have a starting point. __________________ http://www.stanmartin.net http://www.myspace.com/stanmartinsongs http://cdbaby.com/cd/stanmartin3

October 10th, 2006, 01:56 AM	#2 (permalink)
Tremo Friend of Leo's Join Date: Mar 2003 Location: Silicon Valley, CA, USA Posts: 3,767	Could be a tube on it's way south. Could be a plate load resistor. Intermittent problems are a nightmare to track down. Next time it does it, start tweaking knobs to see if any of them have any effect on the noise, that will give you an idea where in the amp the noise is coming from.

October 10th, 2006, 12:34 PM	#4 (permalink)
Wally Friend of Leo's Join Date: Mar 2003 Location: Lubbock, TX Posts: 4,028	Ditto what Tremo says. I would have both channels set up to play...volumes and tones up to a normal setting. When the problem occurs, shut down one channel at a time....maybe you can at least get an idea where to start looking.