I am new here...
My Peavey JSX amp head began to buzz and hum. Yesterday it decided to turn on but now I have no sound. I checked the tubes and I found that when it's set at 16 ohms (switched) there is no sound. When I switch it to 8 or 4 ohms then there is sound and no hum or buzz. I have a 16 ohms 4x12 JSX slanted cabinet so I shouldn't play with the amp at 8 ohms when I have a 16 ohms cab.
Does anyone have any ideas about the amp and whey it doesn't work when it's set at 16 ohms but works at 8 or 4 ohms?
Thanks!
The only difference between the 4/8/16 ohm settings is the output transformer windings selected and the switch itself. What's the resistance measurement (with the amp turned off) between +ve and -ve on the 16 ohm setting? If it's zero or infinite then you've blown the output transformer (or at least some of the windings). Did you do anything bad like run it without a load or on the wrong impedance setting?
If that's ok perhaps the switch is going? Can you give the switch a shot of contact cleaner? If you can squirt it in and turn it back and forth to work it in.
Pop music is about stealing pocket money from children. - Ian Anderson
Sorry to hear of your amp problem. There's several possibilities, I'll cover just the two most likely ones.
It could be the impedance switch has gone bad or the connection to the switch from the 16 ohm tap off of the output transformer has come loose. It could also be that the output transformer has gone bad, possibly due to a shorted power tube, which I suspect from the description you gave of it humming/buzzing and then not working. It's possible one power tube shorted temporarily, damaged the output transformer, then started working again after being turned off, cooling, then being turned back on. It could just as easily be something completely different, however.
It's pretty hard to troubleshoot something long-distance and sight-unseen. Definitely time to take it to a tech. I'd find another amp to use and not use the Peavey until you can get it looked at, as you could very well increase the damage by continuing to power it up.
Good luck.
Strat
Hey, I'm no expert but think both of those responses sound reasonable. I wish I knew that much about amps. You have to like logic. One day I plan to purchase a kit and build a tube amp for the sole purpose of gaining more understanding of their operation.
"Work hard, rock hard, eat hard, sleep hard,
grow big, wear glasses if you need 'em."
-- The Webb Wilder Credo --
I took it to a tech here in Tucson, AZ. I'll let you all know what it is!
Thanks
I got the amp in Sept. of 2007 and I am not sure if Peavey is going to honor the warrany...we'll see. I'll let you know that one too!
Ciao
I got the amp in Sept. of 2007 and I am not sure if Peavey is going to honor the warrany...we'll see. I'll let you know that one too!
If you bought it that recently then I wouldn't touch a thing on it. You don't want to either break something or have them accuse you of breaking it.
Pop music is about stealing pocket money from children. - Ian Anderson
Peavey's been good about backing their products, from my friends' experiences.
Only one of their products I have, though, is an ancient, ugly, much used and abused Backstage Plus that still soldiers along with no problems.
"A cheerful heart is good medicine."
Peavey is not honoring the warranty because of some freight issue. .......
Bummer!
"A cheerful heart is good medicine."
