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Tube Question

I have an amp that has Russian Tubes. This amp purchased in the 90's has always had a hum to it which when playing music isn't heard. I'm thinking of buying 1 6SL7 and 1 6550EH tube to swap out and see if I can find if one of the tubes is the problem. The 6SL7 is Sovtek and the 6550EH is electro-harmonix. Should I replace with a similar tube from another company or continue with the same company? Is this approach to finding the problem sensible or a waste of time?
128x128jcbach
lewm
6,770 posts
 
I've said all I can say. Good luck.
atmasphere's avatar
atmasphere
7,068 posts
 
6SL7s made in Russian often have leakage problems (this is a test on a tube tester) which can introduce hum. We've had such troubles with Russian-made 6SN7s (which are similar but less gain) that we've had to recommend on our website to simply not use them.

OTOH I've yet to see a Russian power tube do that. So yes, you can use other tubes and I recommend it. I would make sure though that the new 6SL7 you use is tested for no leakage on a good tester.
jcbach's avatar
jcbach OP
41 posts
 
@analogluvr  I contacted Andy at your suggestion a few days back through his website and shared what I have for tubes as well as the issues. Still waiting for a response. Not sure if he's on vacation or just not interested :)
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