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Help with what's wrong with my 300b amp?

Hi all tube knowledgable Goners!
I've got a Consonance 300b SET integrated amp with the power coming through my Equi=Tech ET1R with the Si option -(super-isolator option)
The breaker on the ET1R kicked off and I then plugged the amp directly into the wall, thinking my problem was the ET1R, but NOooooo.....that was NOT the problem.
When I powered on the amp, all the tubes EXCEPT the power tubes (the 300b's) came on. While observing the lack of response from the 300b's, the center-located transformer? (if that's what's under the center round thing?) made an electrical "cracking & popping" noise and I think I saw some sparks. I immediately flipped the power switch OFF. I see NO reason to repeat the above exercise!
Can anyone tell me, from the description that I've given, the various possibilities of what could be wrong with, and the damage done to this amp? And any suggestions on who and where to get it repaired, and the possible costs?
Your comments and help are appreciated!
Thanks
myraj
s23chang
619 posts
 
If the 300Bs didn't lit up, there is something wrong with the heater current source. Turn on the amp without the 300Bs and driver tube. Measure the voltage accross the heater current ( pin 1 and 4 )
You should get 5V for each tube. If no voltage then the tube would not light up. Check with AC first then DC. I don't know about your amp and I don't have the schematic so I can't tell if it is AC or DC heater.
Sounds like you might have loose connection for the heater.
Hope this helps
herman
2,256 posts
 
s23chang is correct unless they used a current source for the filaments, in which case you won't measure 5V unless the tubes are in circuit.

Even if there is a loose connection, that would not explain why it tripped the breaker.

I sent a copy of this thread to a friend in Memphis who is a tube amp guru and he may be able to help.
biomimetic
252 posts
 
agree with perfectionist; it does sound like a bad capacitor
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