Need amp repair advice


Drew77
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Joined: 01/26/05
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Drew77
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Joined: 01/26/05
Posts: 191
11/12/2007 8:22 pm
Hey guys,

so I have a peavey VK 112 and the input (my high gain input) port has come lose. It has gotten to the point where I can't even use it. For a while I just had to jimmy it to make the sound come out right but now (probably becasue of all the jimmy-ing) it has stopped working almost completely, the signal is cut off at like 10% maybe. So I was like "well it can't be that much of a problem I can probably fix it myself". So I started taking my amp apart... I stopped when I realized I really don't know what I am doing and I know with computers and stuff that you need to be careful about grounding everything when you are working on them, and I wasn't positive about this. I mean I know there probably isn't a lot of micro chips and such in there as its a all tube amp but I am not really even sure if once I get it open I am gonna be able to fix it.

So before I got to far I thought I would stop and make sure I wasn't over looking anything.

Is there anything I should be careful not to do? Has anyone else fixed this problem and can shed some light on what it is, I mean I am sure that once I get it open I will be able to figure it out, but it'd be nice to know what I am gonna need to avoid putting my only amp outta commission for longer than necessary.

Anyway once I got to taking it apart I realized that it is going to take a while, so I figured it couldn't hurt to ask.
# 1
da_ardvark
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da_ardvark
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11/12/2007 9:49 pm
Lethal Voltages are in there. If you don't know what you are doing, take it to a shop and have it done.

Even unplugged, there are caps in there that will kill you if you touch the wrong thing.
# 2
Drew77
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Drew77
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11/13/2007 4:11 am
I don't know it's hard to believe that amps are crazy booby trapped death machines. I am not just going to be poking random things, it's unplugged. I need to tighten the input port thats it. I don't have the time or the money to take it to a shop for something this silly.

I just want to make sure that I can't break anything simply by taking the top off. The only thing I don't know about is what the problem actually is, I might not be able to fix it since I don't really know how it is put in there it could be something that requires me to replace the piece completely. If thats the case then yeah I might have to take it to a shop but before I spend a bunch of money (and time which as I've said I honestly won't have any until the end of the semester) I wanna make sure it's not some stupid screw or something that I could just tighten.

anyway, if what you said is true than it would be nice if someone tells me what not to touch in order to not die. I'm not accussing you of lying, I just think that sounds like a bit of an exaggeration or at least a fairly liberal stretch of any real danger. Like I said though I don't really know a ton (I am not completely ignorant about this stuff but I certainly have no experience with amps specifically) so I appreciate the warning. I certainly never would have thought something like that was possible.
# 3
BrokenJera
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Joined: 09/25/07
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BrokenJera
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11/13/2007 5:57 am
im no expert on this but i do know iff you touch the worng thing in there even though you might not get hurt you can completely ruin your amp. i would say take it to a shop and ask or even just take 5 mins to call a shop and get some advice but be sure to ask if they can repair you brand/model of amp as some cant and outsorce the work.
They say the END is near, but I'm Tired of waiting.
# 4
strat-man
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strat-man
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11/13/2007 4:21 pm
Originally Posted by: Drew77I don't know it's hard to believe that amps are crazy booby trapped death machines. I am not just going to be poking random things, it's unplugged. I need to tighten the input port thats it. I don't have the time or the money to take it to a shop for something this silly.

I just want to make sure that I can't break anything simply by taking the top off. The only thing I don't know about is what the problem actually is, I might not be able to fix it since I don't really know how it is put in there it could be something that requires me to replace the piece completely. If thats the case then yeah I might have to take it to a shop but before I spend a bunch of money (and time which as I've said I honestly won't have any until the end of the semester) I wanna make sure it's not some stupid screw or something that I could just tighten.

anyway, if what you said is true than it would be nice if someone tells me what not to touch in order to not die. I'm not accussing you of lying, I just think that sounds like a bit of an exaggeration or at least a fairly liberal stretch of any real danger. Like I said though I don't really know a ton (I am not completely ignorant about this stuff but I certainly have no experience with amps specifically) so I appreciate the warning. I certainly never would have thought something like that was possible.



The capacitors inside a valve amp hold 400 volts! That IS gonna hurt!!! if you don't know how to discharge capacitors correctly and safely then for your own safety don't go working inside your amp!
Strat totin
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I met my maker, i made him cry, and on my shoulder he asked me why, his people won't fly thru the storm, i said, listen here man they don't even know your born.

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# 5
da_ardvark
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da_ardvark
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11/13/2007 9:16 pm
Originally Posted by: Drew77I don't know it's hard to believe that amps are crazy booby trapped death machines. .[/QUOTE]

They are not.....if you know what you are doing.


Originally Posted by: Drew77anyway, if what you said is true than it would be nice if someone tells me what not to touch in order to not die..[/QUOTE]

It is true. It's difficult to explain what to touch and what to avoid so nothing will be said on this point

Originally Posted by: Drew77I'm not accussing you of lying,..



That's good

[QUOTE=Drew77]I just think that sounds like a bit of an exaggeration or at least a fairly liberal stretch of any real danger...



It's neither exaggeration nor liberal stretch. It's simply true.

[QUOTE=Drew77]Like I said though I don't really know a ton (I am not completely ignorant about this stuff but I certainly have no experience with amps specifically) so I appreciate the warning. I certainly never would have thought something
like that was possible..


I'm not saying it's rocket science. But you asked and I stand by my advice. Proceed at you own risk.
# 6
nbrothergtr
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Joined: 11/14/07
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nbrothergtr
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Posts: 9
11/17/2007 11:15 pm
Do all amplifiers have large capacitors?
# 7
da_ardvark
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da_ardvark
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Posts: 407
11/18/2007 10:10 pm
It depends on whether you talking physically big or large capacitance. All amps have filter caps to reduce the ac ripple when converted to DC. But tubes require very high voltages to operate. SS amps typically don't require these larger voltages and therefore are RELATIVELY SAFER. That's not to say they are safe to poke around inside.

Another thing to consider before poking around inside ANY amp if you don't know what you're doing, is the costly damage you can do. On some solid state amps (SS) you can fry parts that aren't even available anymore, rendering the amp useless.

My advice to anyone who is having amp problems and doesn't know what's going on inside..........Take it to someone who does know.
# 8

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