Home » Audio » Thermionic Emissions » Buzz in Peavey Classic 50 tube amp
Buzz in Peavey Classic 50 tube amp [message #74792] Sat, 08 December 2012 13:45 Go to next message
TurnItUp  is currently offline TurnItUp
Messages: 75
Registered: April 2012
Location: Atl
Viscount
My Peavey Classic 50 tube amp has got a buzz in it everytime I turn it on or try to play. Anyone have any quick fix suggestions?
Re: Buzz in Peavey Classic 50 tube amp [message #74802 is a reply to message #74792 ] Sat, 08 December 2012 20:36 Go to previous messageGo to next message
Wayne Parham  is currently offline Wayne Parham
Messages: 16836
Registered: May 2009
Illuminati (33rd Degree)

How long since the last time you turned it on? Have you ever replaced the power supply caps?

If it isn't used often and the caps are old, I'd swap 'em out and see if it wasn't better.

Re: Buzz in Peavey Classic 50 tube amp [message #74841 is a reply to message #74802 ] Sun, 09 December 2012 20:34 Go to previous messageGo to next message
Shane  is currently offline Shane
Messages: 1108
Registered: May 2009
Illuminati (3rd Degree)
Is the buzz less when you have your hands on the strings? If so you may have a ground issue. I had a ground wire that broke off the trem on one of my guitars and the buzzing was horrible.

Do you have any appliances that are on the same circuit? A refrigerator or anything that cycles and is on all the time can make a terrible racket through your amp.

Have you removed and reinserted the tubes? Sometimes a buzzing sound can be from dirty tube contacts. Make sure the amp is unplugged when you try this Smile

Sometimes a bad tube can cause it. Try putting in a new 12AX7 in the preamp positions and see if that helps. Again, unplug first.

I have a tube amp that is over 40 years old and doesn't buzz. My other tube amps that were over 12 years old never buzzed either. Wayne is right, though, if it's older it might need a recap, especially if it hasn't been used in a while. But I guess I've been fortunate and never had to recap yet.

Another issue might be the input jack on the amp itself. Bad solder joints could cause it.

And the end-all-be-all...do you have a local tech to look at it? If none of the above work take it to someone you trust to give it a look over.



Rolling Hills Imagery - Photography by Shane
Re: Buzz in Peavey Classic 50 tube amp [message #75375 is a reply to message #74841 ] Mon, 28 January 2013 18:08 Go to previous message
Thermionic  is currently offline Thermionic
Messages: 208
Registered: May 2009
Master
If the hum happens immediately after power-on, as soon as the tubes warm up enough to conduct, it's likely filter caps if it's a Classic 50. I've had to replace the caps in humming Peaveys and Fenders that were only a few years old. Granted, they belonged to players that practiced and gigged much more heavily than your average Joe, and therefore had more hours put on 'em in those few years than most amps see in a decade or more. But, their poor quality Illinois Capacitor power supply caps were nevertheless bad after only about 3 or 4 years.

If the amp is quiet at first but them hums after several minutes and gets worse after the amp's been on for quite a while, it's probably a bad power tube.

Shane wrote on Sun, 09 December 2012 20:34
Another issue might be the input jack on the amp itself. Bad solder joints could cause it.


Peaveys are notorious for cold wave-solder joints on the PC board. I've fixed a bunch of 'em. They're often only visible under magnification and strong light.

Thermionic
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