Bare Knuckle Pickups Forum
Forum Ringside => Tech => Topic started by: BigK on July 18, 2012, 05:58:31 PM
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As the title says my Powerball just died.
I turned it on loud static like noise (first i thought it was picking up a cb radio) then strummed a few chords and all seemed fine. Then there was a couple of loud pops and no noise.
The LEDs were still ON on the front of the amp, but then I caught a whiff of burning and immediately turned it off.
Could it just be the power valves failing? I've not changed them for quite a few years? anything I should check before I start throwing cash at it?
+ Can anyone recommend an amp tech in the Stoke/Stafford area?
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This exact thing happened to a friends bugera and it was one of the screen resistors that burnt out.
If you are comfortable with taking it out of the headshell and taking a photo that would help.
Also did you notice if there was any redplating going on?
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This exact thing happened to a friends bugera and it was one of the screen resistors that burnt out.
If you are comfortable with taking it out of the headshell and taking a photo that would help.
Also did you notice if there was any redplating going on?
I quickly looked at the valves before I shut it off and they looked normal to me.
I took the chassis out of the case but all the PCB's are upside down and its not completely obvious how to release them - although I've had a couple of whisky's so I'll look again in the morning.
I can't see any burning around the pcb. Ive had a quick look around valve sockets and cant see much.
Will get some pics tomorrow.
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You can't usually tell if a tube's developed an internal short just by looking at it. Loud pops could mean a tube going bad, the burning smell could mean a resistor going open circuit, maybe a coupling cap has blown open or if you're very unlucky then it's a transformer problem.
A quick look at the PCB - when you're fully sober - will probably show up an obvious dead component.
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A quick look at the PCB - when you're fully sober
One cannot stress this enough : "when you're fully sober". The power supply caps store lethal voltages (400+V DC) for many hours after you unplugged your amp, so better a dead componant than a dead guitar player.
and this will be my 1000th contribution to this forum... hopefully a useful one :mrgreen:
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A quick look at the PCB - when you're fully sober
One cannot stress this enough : "when you're fully sober". The power supply caps store lethal voltages (400+V DC) for many hours after you unplugged your amp, so better a dead componant than a dead guitar player.
and this will be my 1000th contribution to this forum... hopefully a useful one :mrgreen:
A very useful one which I fully support - the voltages in a tube amp must be respected at all times.
Cheers Stephan
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I've finally got round to sorting this out as I've been using my Peavey Vypyr 30 for a while as my focus moved to my car for a while.
Anyway it was a dead power valve so I replaced the JJ's that were in there with a set of cryo JJ's and had it re-biased and it sounds better than ever!
Although it might not be around fro much longer as a secondhand mesa Roadster has popped up nearby that I might not be able to say no too. 8)