Ok, Something happened to my GA-30, two of the big tubes wont light up. Only one will, and it lights up really really bright and gets really hot really fast, not like usual. I'm afraid to play it, what's up? I know there's like 4 differnent versions of the GA-30, and I have no idea what mine is, but it's got, from left to right: two big tubes, vertical to eachother, a big black box, a big tube and a little tube vertical to eachother, then two little tubes vertical to eachother. What's the big black box and the names of the tubes anyway? I'm such a smuck at amps.
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Umm......Oops Calling Kent S.!
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Re: Umm......Oops Calling Kent S.!
My hypothosis:
The 2 tubes that aren't glowing are broken (Bean backed this up by saying that they had a kind of powdery look inside). The 1 tube that is working is heating up extra fast because it needs to make up for the work the other 2 tubes aren't doing. No sound came out because it can't do the jobs of the other 2 tubes.
My professional reccomendation:
Change the tubes, be sure to get high quality tubes.
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Re: Umm......Oops Calling Kent S.!
Hey Guy,
Please understand that any complete and accurate determination of the problem can only be had under a tech's *on hands* inspection. That being said ... I got the impression from you that this baby was ... Well, how shall I say it? ... A little old and not cared for ... First thing if the tubes were never replaced since when ever (regarding that post you made of such nature) ... Well ... Man, look it's like this ... it could be a bunch of things ... heater line failure, supply line failure, cathode connection failure (not likely) ... as old as that amp is and since you don't know when the last time tubes were replaced ... it's probably the tubes ... thing is, you really need to have it checked over to make sure that everything else is cool ... meaning NO shorts on Da Board, trannies are good, and the rectifier (as some have a separate split to the power stage) are good.
In short though ... It could be your heater line to the power stage is dead ... if the tubes don't even light up ... well that means they are getting NOTHING from the heater lines. Another thing is that maybe the section of the input tranny that feeds it is dead also (since there is no heater action; some trannies have separate outs for preamp tube heaters , which could account for the fact that you might still have the preamp tube heaters running ).
Sorry Bro, but I don't know how that particular amp is laid out, but the cool thing about the old tube designs is that they are pretty straight forward in troubleshooting (once hands on). You can always try a new set of tubes ... but I would have it checked first. Sorry man if I can't be more help ... It's kind difficult from this distance ...::::To sound reinforcement engineer::::
... What? ... ::::snicker:::: ...Yes, ... Right, ...
Could we please have everything louder than everything else ? ...
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Re: Umm......Oops Calling Kent S.!
That's what pisses me off the most. I did get the amp service. 175 bucks. Replaced all the tubes ('cept for the small ones) and several caps, and what appears to be a transformer. All this was done less than a month ago. As far as I know, tubes dont go out in less than a month. And, on the bottom of one tube, the little plastic thingy's broken off and you can see where the glass was formed to keep the air out and whatever gas they put in there, in.This is the very perfection of a man, to find out his own imperfections. - St. Augustine of Hippo
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Re: Umm......Oops Calling Kent S.!
Tubes can die at anytime. Basically, all products have a higher level of failure either early on or later toward the end of it's life. I've had tubes go out within days of re-tubing. Sometimes it's the tube itself and other times it's something else going on with the amp to blow the tubes.Not a 5150 Kramer, but a 5149 1/2 Shamer
www.bigmouthbetty.com
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Re: Umm......Oops Calling Kent S.!
I had a similar problem with a Fender Bandmaster. Basically, IIRC, the heater circuit (or bias supply?) had cooked itself. My advice would be...don't turn the amp on again, and take it back to the tech that fixed it.
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Re: Umm......Oops Calling Kent S.!
Will do monday. Should I pay for it to be fixed again, or should I ask for him to fix it for free? The guy who fixed it is really nice, and pretty cool, but the local shop owner is a d*ck and will want to charge me, even for just giving me his phone number.This is the very perfection of a man, to find out his own imperfections. - St. Augustine of Hippo
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Re: Umm......Oops Calling Kent S.!
I'd be nice about the situation first and say "I just brought it here to be retubed a month ago... will I have to pay for it again?" If they said yes, I'd unleash the raging, pissed off Italian that lurks deep within my soul.
That was almost 200 bucks of your hard earned cash man, I'd give them all holy hell if they try and make you pay again. Unless it was your fault (like you threw a brick at it or left a bag of empty cheetos over the tubes), I'd be really persistent about not shelling over the cash again.7 FREE TRACKS OF ROCK - driftrocks.bandcamp.com
PARTY - pulsepartyband.com
In mother Russia, pedal overdrives you.
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Re: Umm......Oops Calling Kent S.!
Originally posted by joelapI'd be nice about the situation first and say "I just brought it here to be retubed a month ago... will I have to pay for it again?" If they said yes, I'd unleash the raging, pissed off Italian that lurks deep within my soul.
That was almost 200 bucks of your hard earned cash man, I'd give them all holy hell if they try and make you pay again. Unless it was your fault (like you threw a brick at it or left a bag of empty cheetos over the tubes), I'd be really persistent about not shelling over the cash again.
Expensive,, but better for the customer ... plus it teaches the techs to be more careful.::::To sound reinforcement engineer::::
... What? ... ::::snicker:::: ...Yes, ... Right, ...
Could we please have everything louder than everything else ? ...
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