#1
So I blew my tubes on monday, but after i inspected them I knowticed that the filiments were melted, then I looked at the fuse, and it was melted, before the tubes blew, they glowed red and put out enough heat to match the Sun, then died, and the light wont work either, dont know if thats normal. I'm wondering if theres a problem with the circutes or if its just the tubes. Or what else i should do, since I dont have the money to take it to a tech.

Btw, its a Peavey Valveking 112.
#3
perhaps you got a fuse with too high a resistance
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#4
I gig with it at volume at around 5-6 and the amp was bone stock, I bought the floor model in december, since it was the last one they had.

EDIT: btw, it did all the heating up to the sun and dying crap on me while I was praticing, at around volume 2
Last edited by ethan_hanus at Mar 10, 2009,
#5
Wouldn't it be too low of a resistance? Because if it was too high, your whole amp would probably blow, too low, they would just melt. Probably like a fuse blows. I don't know, that is just what I would pull from it
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#6
the tubes sound like they were biased WAY too hot!
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#7
Quote by cblowrun
Wouldn't it be too low of a resistance? Because if it was too high, your whole amp would probably blow, too low, they would just melt. Probably like a fuse blows. I don't know, that is just what I would pull from it


Well, fuses protect from too much curret going into the amp and frying the thing, but it melted so to much current did go into the amp, but the tubes still melted, I'm still a bit confused.
#8
ethen - I'm going to try to find you some help. I know you don't have a lot of money but you really need to take it to a tech. Putting new power tubes in is probably not going to fix anything. And as you stated, I doubt a fuse caused all of this.

My guess is that one of the Power tubes became unseated in transport or something which either caused an arc or forced 1 tube to do all the work. Power tubes work in pairs etc.

#9
It sounds like a bias problem or a PT problem. It needs to go to a tech, since you'll most likely just blow the next pair of power tubes that goes into it.
#10
don't play so br00t4l next time.
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#11
Quote by 311ZOSOVHJH
ethen - I'm going to try to find you some help. I know you don't have a lot of money but you really need to take it to a tech. Putting new power tubes in is probably not going to fix anything. And as you stated, I doubt a fuse caused all of this.

My guess is that one of the Power tubes became unseated in transport or something which either caused an arc or forced 1 tube to do all the work. Power tubes work in pairs etc.



Thanks alot, I'll see if I can enough money for the tubes, then enough for the tech, might take awhile, but anything i can do myself would be awesome.

But for now, Fender Frontman 15G amp time!!!
#12
Quote by ethan_hanus
Well, fuses protect from too much curret going into the amp and frying the thing, but it melted so to much current did go into the amp, but the tubes still melted, I'm still a bit confused.

I think that if it melted it meant their was too much current for the tubes to hold which means that you probably need some higher resistance tubes. It is worth a shot I think but maybe someone else has a better idea. If the tubes were too high of a resistance not too much would have happened to the actual tube, just the circuitry inside the amp
Make a joyful noise.


Guild M-30

Peavy Audition 110 amp hey, i'm actually proud of this one.
boss ME-50
www.iamterrified.com
#13
Do what Roc8995 suggested. He is a resident tube expert and is a mod for a reason.

Like I suggested in the VK thread - you might be able to find an EE or amp tech on craigslist or a friend in school or something that won't charge an arm and a leg like a chain store would. You will need new power tubes obviously, but I didn't want you to go buy those only to have them fry as well.

Roc -

PS, ethan PT = Power Transformer (not power tubes).
#15
it's just a blown tube man. Re-bias it cooler and put new PT's and a new fuse in it.
I've bought, sold, and traded more gear than I care to admit.
#16
Quote by 311ZOSOVHJH
Do what Roc8995 suggested. He is a resident tube expert and is a mod for a reason.

Like I suggested in the VK thread - you might be able to find an EE or amp tech on craigslist or a friend in school or something that won't charge an arm and a leg like a chain store would. You will need new power tubes obviously, but I didn't want you to go buy those only to have them fry as well.

Roc -

PS, ethan PT = Power Transformer (not power tubes).

I was planning on buying the tubes, and not installing them till I have a tech look at the amp, I'm still fairly new to tube amps, so i didnt know that^, learn something new everyday.
#17
Roc8995 is probably right. If the tubes were glowing red, it's most likely a bias problem. If the plates were dissipating enough heat to melt the filaments then that's pretty bad.
#18
Sounds like you blew the bias circuit all together. It's the one downfall of fixed biased amps...if the bias circuit stops working for any reason, you are screwed. Lets through probably ten times more current that it's supposed to...tubes can't handle it, so they start glowing red (a friend of mine got his all the way to a bright orange, that was neat) very fast. If you've heard of "red plating" because of biasing something too hot, it's like that taken to the next level.

Make sure the tech checks out the output transformer too. If the bias circuit dies, that's the likely piece of iron to die with it (theoretically, the PT should be fuse protected).
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#20
Quote by 311ZOSOVHJH
The amp is non-adjustable fixed though (meaning it doesn't have to be biased when changing tubes)


Doesn't have to be adjustable. There is a series of resistors/a diode/some caps that create the voltage used in fixed bias. If any of those components die, you lose you bias voltage (it becomes zero volts).

The bias voltage is like the "dam" holding back the electrical current. When the dam bursts, current comes flooding through, and your tube is melted.
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#21
Might just be a bad tube. I had the fuse popping in my Pro Jr and it was a bad EL84.
#22
Quote by DLrocket89
Doesn't have to be adjustable. There is a series of resistors/a diode/some caps that create the voltage used in fixed bias. If any of those components die, you lose you bias voltage (it becomes zero volts).

The bias voltage is like the "dam" holding back the electrical current. When the dam bursts, current comes flooding through, and your tube is melted.

#23
possible silly question: Sorry to hijack, but my tubes always glow red and are always really hot :P theyve doing this for over a year since i got em, is this a problem?
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#24
Are the plates glowing, or just the filaments? Red plates are bad news. Heat is normal.
#26
Seriously, PM IbanezPsycho. He's an amp tech, he's owned a Valveking, and he lives in Texas. I'm not saying he can/would fix it himself but he might know of some people that can help for a lot less than say GuitarCenter.

http://profile.ultimate-guitar.com/IbanezPsycho/

#27
Quote by ethan_hanus
so if it is a bias problem, and one of the resistors or caps etc. fryed, is having the amp fixed going to cost alot?


If the bias is bad, it'll be a couple of components, shouldn't be too much. Would take me about an hour or two tops to fix (95% of the time is tied up in disassembly).
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#28
Quote by Roc8995
Are the plates glowing, or just the filaments? Red plates are bad news. Heat is normal.

the plates were red, and it was putting out too much heat, it normaly ran just enough heat to barely feel. I dont know if playing on full gain, with boost on most of the time would do that, I have my settings at bass-9 middle-4 tremble-9.
#29
Quote by ethan_hanus
the plates were red


bias problem...dunno how you could have a tube destroy itself so that happened, without something dramatic going on inside (arcing, etc...).

You tubes MIGHT be OK. probably best to replace them.
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