Thread: PLEASE HELP!!! HEAD BLEW ON TOUR!!! AMPEG SVT II 1989 TUBE HEAD

I don't know what a power transformer looks like, but this looks like a regular little tube fuse with 10 A 250 V written on it then underneath where it goes is written "10 AMP fast" in pen ink so i think it's a regular fuse, it's just all white. it almost looks like i would expect a blown one to look but the white is so even and consistent throughout the whole fuse that it's hard to think that it's...

Nah, there's a couple places in Dallas. But the turnaround time is really slow. What band are you in?

Maybe somebody popped a resistor in the fuse slot? If so, it's allowing 250V in where the amp wants a max of 125, so that could be trouble.

By the way you made have blow a resistor, that would some time send more voltage to your tubes and make them bright.

Quote: Originally Posted by KUNGfuSHERIFF Maybe somebody popped a resistor in the fuse slot? If so, it's allowing 250V in where the amp wants a max of 125, so that could be trouble. With a diagnosis like this I now understand why Clapton shot the sheriff! Paul

Quote: Originally Posted by KUNGfuSHERIFF Maybe somebody popped a resistor in the fuse slot? If so, it's allowing 250V in where the amp wants a max of 125, so that could be trouble. Potentially problematic, but only if he plugs into a 240 V outlet (like a washing machine outlet).

Quote: Originally Posted by jdaustin thanks for all the help everyone. i had to open up the bottom of the whole head just to get to a fuse. is a 10 amp 250 v fuse but it's powder-coated white so i can't see if it's blown. it is for sure just an svt II and not a pro. i have 6 6550 tubes and 2 little 12au7a tubes and 4 little 12ax7a tubes. I'll go get a fuse now to see if that's it. any other help is appreciated,...

+1 to above post. Bad power in a venue sounds like the culprit & most likely IS just a fuse! Has happened to me on a few occasions over my lifetime of gigging w/ all tube amps. I USUALLY take my Mark Bass LMII along as a back up amp- seeing it's SO SMALL( I use a brief case to carry it & pwr, spkr & a couple of gtr leads!!) & light & sounds great too. NO match for an all tube SVTII tho. I've...

it could possibly be the bias died on the amp which blew the tube(s), which then blew the fuse from shorting. that would explain why 3 tubes lit up brightly before the amp dieing.

Quote: Originally Posted by jdaustin thanks again. can anyone give me an idea on how much money and how involved it would be if it was the power transformer? I am familiar with the tube costs and i assume the fuse wouldn't be enough to break me. thanks again. you've all been a huge help. also, this is still weighing on me. is there a chance i've just "totalled" my head? thanks it wont be the power transformer...