Need Tubes

I think that the same factory makes both EH and Sovtek tubes. I cant understand why you would put tube dampers on power tubes as these tube types are rarely microphonic. 

I agree with the Tube Depot, great site, good prices, quality products.   They have good, high temperature tube dampers on site, too.   They are low cost and it never hurts to squish microphonics in voltage gain stages, even tiny ones.

Upscale Audio or Viva, I have had nothing but good experiences with both.

audition_audio, the 6H30Pi is not a power tube; it's in the preamp. Microphonics in the gain stage of a preamp should definitely be addressed, as the signal reaches the amplifier, the "ringing" gets amplified as well.

+1 for Tube Depot. They are great guys. I say get some JJ gold pins over the EH and your good to go without spend much money. I have a LS25mki and its a very good pre.