Tube Question

[clmjlg]

So my power tubes in my ampeg svt-cl have gone bad and my amp wont stay on for more than 20 min. So im trying to get a set of tubes and was wondering if anyone had any good suggestions. I know ebay has some but i thought maybe someone would know more here. Im looking to spend in the 250$ range if that helps.

 

[toomanyslurpees]

Last time I retubed my SVT-CL I put in JJ KT-88s on the advise of a tech being that I was looking for a bit cleaner sound than the tubes I had in there (sovtek 6550s) it cost me about $300 when I did it but that was pushing ten years ago, I don't know if that would be more or less today. I've been pleased as punch with the tubes. I don't use this head as much these days, I still love it and would part with it, but I wanted one head I could use for everything and the classic is a bit much for a coffee house.

 

[Caca de Kick]

You sound like you have something else going on other than a tube issue. Either the tube output stays on or it doesn't, power tubes don't just stay on for 20 then quit. Sounds like a heater circut issue. You need to take it to a tech.

Besides, old tubes don't mean anything either. As power tubes age you can adjust the bias to keep them operating at peak performance.

 

[clmjlg]

Well the signal light begins blinking from green to red and everything i can find on that says the power tube is going bad. Also i let them heat up and noticed a considerable difference in the amount one the tubes lit up compared to the others and thats what i was told to look for in a bad tube. But i might get it checked out only problem i have to drive an hour to get it checked out and money is really tight now so there is really no win here.

 

[toomanyslurpees]

I've had my protection circuit kick in twice, once was a blown tube, the other time was at a crappy bar with questionable power (think I was probably on the same circuit as the stage lights) I would guess you're right with a blown power tube. Just don't try to crack that thing open, I'm also on a tube amp building forum and even those guys are scared of that thing, there is high enough voltage in there to kill you.

 

[Caca de Kick]

You can simply swap the tube to a different socket to see if it's the tube or the socket.