2. amps-preamps
  3. 1386083471

Broken tube on Art Audio Carissa 825 amp

I have neglected my main audio system for a while - once I figured out that I really couldn't tell the difference between a $600 power cord or speaker cable and the ones that came with the equipment, I somehow lost the urge to keep "improving" it. :-o

I decided it was time to dust off the equipment and get it working again - I do still love to listen to music even if I do apparently have a tin ear - but discovered one of the tubes on my amp has broken. I am thinking my cat was the culprit but I really don't know. The broken tube is a Ei 12BH7 (Yugoslavia.) Do I need to replace it with the exact same brand and model of tube or is there a better one to try? If I replace the tube with something different, is it best to replace the similar tube on the other side with the same thing?

Also, I have been out of the game for a while; please recommend some good places to purchase tubes.

Of perhaps more concern is that some of the glass from the broken tube has fallen down inside of the amp - should I panic? I tried to remove some of the broken bits with a pair of hemostats but only managed to push it down into the guts... DOH! Other than taking the amp apart - which I am most reluctant to do, for obvious reasons, and not even sure if I Can do it- I am not sure how to remove the glass bits. :-(

Holly
oakiris

Showing 1 response by bill_k

bill_k
884 posts
 
Holly,
Regarding the broken 12BH7 tube, first I would try to remove any more of the broken tube bits left in the amp. Have you tried holding the amp upside down and seeing if you can get any more broken pieces to fall out? I know that the amp is heavy but that may be your best shot at removing the remaining pieces short of opening up the case for surgery. If the broken bits are just glass you'll probably be ok, but if there's any metal then you could have a short that could cause extensive damage if you power it up. Do so at your own risk! As far as replacing the tube, I would strongly suggest that you replace that tube in both channels so that they have a matching tube complement. Otherwise the two stereo channels may have a difference in sound quality. You do not need to get the same brand of tube, just 12BH7 tubes or equivalents should do fine. The Tube Store is known to be a reputable supplier, and they currently show three choices of that tube type being available. Best of luck and let us know how it goes!
More to discover