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Question about a guitar amplifier

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Beebo

New Member
I have a tube amp(Peavey Valveking) and not knowing any better I replaced the fuse (5amp250v fast acting) with a slow blow fuse. Now my amp turned on but I cannot get any sound of any sort out of it. Does anybody know what I might have messed up?
 

Sceadwian

Banned
Have you checked to make sure all your tubes are working?
 

Beebo

New Member
Only the four 6l6 output tubes for sure are working. Im too scared to turn on my amp again until I get the right fuse because if I haven't messed anything up yet I'd like to keep it that way.
 

Sceadwian

Banned
The wrong fuse isn't going to cause the amp to suddenly explode unless there was something already fatally wrong with it. Did you determine what caused the fuse to blow?
 

Beebo

New Member
I'm pretty sure it was one of the output tubes being messed up. Because when I traded with the slow blow fuse, the amp turned on and the 3 of 4 output tubes lit up. But I get absolutely no sound from the amp at all. So I'm afraid that when I put the slowblow fuse in I messed something up in my amp...
 

Sceadwian

Banned
Have you replaced the output tube to see if that's what it was? The fuse isn't going to cause anything else to break that wasn't already broken before unless you have all sorts of dead shorts inside, all you're talking about is the difference between how fast the fuse blows, as long as it was the right current rating fast/slow blow isn't going to cause the world to end.
 

Mikebits

Well-Known Member
Maybe your new fuse was no good. Have you checked it?

Never mind, you say your amp turned on...Strange it died upon changing fuse though.
 
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Beebo

New Member
Ok, well that makes me feel a little better. I've replaced the output tubes and still get no sound, would switching back to the fast acting fuse possibly fix this? If not I'm going to check the preamp tubes to see if those are not working either.
 

Mikebits

Well-Known Member
A fuse is not a drug. No adverse side affects from using one, other than if a problem in the amp arises and it does not blow when a circuit is failing.
 

Mikebits

Well-Known Member
Why did you change the fuse in the first place? Was there a problem which made you try to change it?
 

Beebo

New Member
One day I turned on the amp and the fuse blew, so I took the fuse to radioshack and they pointed to the replacements for it, so I took the fast acting fuses back and tried them and of course they blew. I know nothing of electronics really so I got a slow blow fuse of the same voltage and amps and tried it and after that is when I got power, but no sound. I saw that one of the tubes wasn't lit up so I replaced the 4 output tubes and still get no sound. Tomorrow I'm going to go back to the fast acting fuse (even if it doesn't matter I know now after more research that it's the kind it needs because it was labeled F5a) and I'm going to see if the fuse blows when I turn it on.
 

Mikebits

Well-Known Member
The fuse is not your problem. It is there to keep you safe. Something in your amp has gone bad. Pull all the tubes and see if correct fuse still blows. Use right fuse, not slow blo.

What I mean when I say pull, is to remove and the apply power.
 
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Nigel Goodwin

Super Moderator
Most Helpful Member
It's unlikely to be a valve blowing the fuse, more likely the rectifier (that's probably a silicon diode or bridge) has failed, or the mains transformer is shorted turns.

Repeatedly putting fuses in and blowing them won't have helped anything, as will fitting a slow blow fuse in place of a fast blow one - assuming the rectifier was short, it might have now killed the transformer.

But valve amps are crude, simple, and easy to repair - but you do need some knowledge about them.
 

flat5

Member
When you apply power do you hear anything from the speaker?
A thump, a hum, noise? If no, but the tubes light, first check the speaker connections - the wires, at the speaker end and the plug.
Report back to us.

What model amp is this? Does it have two power switches? One a standby? Does the standby switch "feel right" and click when you toggle it?
 
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