Mosvalve 1500 - 60 cycle hum

Dave Smith · From: Whipple/Marietta, OH USA

My power amp over-heated one night on a gig. Had a noticeable drop-off in power output. Ever since, I have a very irritating 60 cycle hum - this is present with everything else turned off and nothing plugged into the amp. Other than the hum, the amp seems to work fine. Any thoughts??

Jack Stoner · From: Kansas City, MO

You probably "fried" the power supply, or one of the components and probably a filter cap. It's going to have to be serviced.

When I bought my used MV500 power amp, I talked to the factory and the tech told me to make sure it got adequate ventilation. I can see now why he said that. I have mine in a Calzone (Anvil style) rack case and have 5" round air holes in each side of the rack. This keeps it running relatively cool and I can leave it powered on all night at a gig.

Dave Smith · From: Whipple/Marietta, OH USA

Jack - Do you know if they have a factory service department like Peavey does? You are absolutely right about the ventilation. I have this in a 4-space rack and that night I left the bottom door closed during the gig. Wasn't til I started noticing a loss in power that I realized what I had done. The only air it was getting was through the space between components. That was near the end of the third (of four) sets so at the break I opened it completely and it cooled enough to finish the gig. The next day the amp seemed fine except for the hum. I'd like to have it factory serviced if they provide that service. Dave

Never mind - I found the TubeWorks web page and 4 authorized service centers here in Ohio.

[This message was edited by Dave Smith on 29 October 2001 at 12:19 PM.]

Kevin Mincke · From: Farmington, MN (Twin Cities-South Metro) USA

www.genzbenz.com

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