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Fireworks in an Audio Research VT200

I turned on my amp the other day and as it was cycling through the start up process, I heard a large pop and then an enormous fireball flew out of the top of it. I immediately unplugged the amp. After taking all the tubes out and visually inspecting everything, I concluded that no tubes were blown. I put it all back together and it sounds great and I have had no problems since. The bias is fine.

Has anybody had experience with this sort of thing?
jmcdermott

Showing 1 response by micheal

micheal's avatar
micheal
29 posts
 
Hi
I have repaired several ARC VT 200 amps with this situation.
It typically starts when one of the output tubes shorts and causes an arc in the plate or cathode ciucuit. It burns away some of the conducting trace ( hence the fireball) and sometimes takes out a resistor on the cathode or screen.The related tube should be tossed out and replaced.

I WOULD NOT CONTINUE TO USE THE AMP IN THIS CONDITION.....

Right now it is an easy and inexpensive fix.
Best to keep it that way.
Good luck.

Mike

The 200 banks several tubes onto one adjustment
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