trinityamps.com

My two EL84s blew and they didn't just blow, when I tried to take them out, the glass came out of the socket and flaky white residue that had gathered in the top of the tubes came out of the glass tubes.

So, I'm wondering, since both tubes blew, is there possibly a problem with this part of the circuit?

I was using GTs. Will be replacing likely with JJs.

Any thoughts are welcomed and appreciated.

(and apologies if this post is in the wrong place)

Sounds like the vacuum seal was broken. I would think it was mechanical that broke the tubes i.e.. got knocked hit. Is there any burnt componets in the circuit.

just in case I would redo the power up sequence before installing new tubes

Thanks for the reply.

The circuit looks fine. No obvious signs of trauma. I used my light bulb limiter and tested the power up. No problems. The new tubes seem to be fine (amp is working normally again) but I remain concerned about potential voltage problems. Surges from the mains can be ruled out as I use surge protection and power conditioners for my amplifiers and effects chain(s).

What is the pate voltage and cathode voltage on you power tubes?

_________________
Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

I was afraid you would ask that Stephen.

I have it all back together at the moment. If I get ambitious this weekend or next, I will get some numbers and post them here. Thanks for chiming in - will have more soon.

John