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AMPEG SVT HELP

I

iandi.bass

May 20, 2009
30
0
#1
I have a U.S.A. made SVT Classic. I am not very handy with amps or anything of the like. I was just wondering if anyone knows what will happen if I take out one of the tubes? Like if one tube is missing and I turn the amp on and play with it, will it even make a sound? or will it just cease to work?

And if not, is there something I can do to the amp(aside from breaking it) that could give it the appearance that it does not work?
 
#3
what a whacked out question! what possible reason could you have for taking out a tube and trying to play it?

here's a general rule of thumb for you...if it sounds like a really dumb idea, 99 times out of 100 it is.
 
#4
iandi.bass said:
And if not, is there something I can do to the amp(aside from breaking it) that could give it the appearance that it does not work?
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waitasec! i get it now! you're borrowing a CL on a trial basis and trying to pull a tube out and bs the seller into thinking it's broken so he gives you a better deal, aren't you!

geez, whatever happened to honesty? DEVO was right...de-evolution is real, and it's things like this that prove it.
 
#5
JimmyM said:
waitasec! i get it now! you're borrowing a CL on a trial basis and trying to pull a tube out and bs the seller into thinking it's broken so he gives you a better deal, aren't you!

geez, whatever happened to honesty? DEVO was right...de-evolution is real, and it's things like this that prove it.
Click to expand...

Probably something along those lines. Either way, it doesn't smell good to me.

As far as pulling a power tube, that will just alter the interaction of your power tubes and output transformer. You'll have less output but will change the "expected" output impedance of the amplifier thus plugging into the same cabinet will potentially damage the reamining tubes, output transformer, or both.
 
#8
I was asking this because I was told it was possible, when you change tubes, that the amp(light) would be flashing as if broken, but it would actually still work, it would just take a while before setting 'correctly' and I wanted to know if it was true before I cracked it open and started changing things. Thanks for the help and doubts though....
 
#9
iandi.bass, in your initial post you wrote something very important, especially when owning an SVT or any all-tube amp :

iandi.bass said:
I am not very handy with amps
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There's a very simple rule when one is not handy with amps (I am not either) : have maintenance done by a tech. That's somewhat insurance for the health of the amp.
 
#11
I was told its not too difficult to change tubes and etc. But if I need tech support, what sort of places do that? Do I have to ship it to Ampeg or something? Or are there shops that will do it, cause I'm sure shipping will take like 3 years
 
#12
Guys there are more tubes with different functions than just the output tubes (the big ones). Most topologies remove any "small" tube and the amp will no longer function, remove the phase inverter and I can guarantee a dead amp. :rollno:
Don't play in there if you are not prepared to pay in the end. :cool:
 
#13
iandi.bass said:
I was told its not too difficult to change tubes and etc. But if I need tech support, what sort of places do that? Do I have to ship it to Ampeg or something? Or are there shops that will do it, cause I'm sure shipping will take like 3 years
Click to expand...

Don't know where you live and thus don't know how things work there, but where I live, my main local shop works with a tech company, specialised in music electronics (amps, effects, etc.). And anyone can bring them his/her amp for tube changing or anything else.

If it's just changing the tubes, my local tech does it on-the-fly. Cost : price of the tubes + 40 euros (one hour of workmanship).
 
#14
iandi.bass said:
I was asking this because I was told it was possible, when you change tubes, that the amp(light) would be flashing as if broken, but it would actually still work, it would just take a while before setting 'correctly' and I wanted to know if it was true before I cracked it open and started changing things. Thanks for the help and doubts though....
Click to expand...
sorry i questioned your veracity in that case. but let's face it, you worded it in a way that made it seem like something a little shady was going on ;)

anyway, the little tubes can be changed easily by you. the big tubes should usually be changed by a tech so he can bias them when he's done. the bias lights are used mostly for tweaking tubes that have already been professionally biased or to let you know of a potential problem, and there are a different set of bias adjusters inside the amp for the tech to use that are a lot more accurate.

but don't run your amp with an empty tube socket. even if it doesn't blow up, it's not good for it.
 
#16
Bluesbob said:
I used to pull two of the output tubes, along with disconnecting one of the speakers in my Fender Twin. Never caused any harm.
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Because you were completely theoretically correct in what you did.....

But for the OP I'd say don't do it unless you check the schematic. And if you can't read a schematic - don't do it.
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That is also very correct......!

of all the amplifiers to mess around inside of, the very last one that would be suggested is an SVT (or any other big power tube amp, actually)
 

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