Luxman preamp into Mark Levinson amp?

@squirrely , I got mine from Vivatubes, reliable seller with 90 day warranty, they’re selling those now for $49.44 each. Just get a trio or quintet of matched sets, they got both options. If there’s noise, you’ll hear it from your speakers (like loud hiss or humming, etc), microphonics sound like if you put a giant mosquito against the microphone, just imagine that noise is amplified and comes from your speakers. Extremely annoying.

Those double triodes tubes, in this case 12xx7 type, have two sections, and it’s surely preferable to have them matched.
 

@squirrely go to thetubestore (Canadian dealer) and take a look at their Gold Lion 12ax7 tubes. They make long plate and short plate version. You’ll see those two blackish things inside of the bottle in one version are long, and the other version is short. Compare them visually, and you’ll see the difference. Same goes to the NOS stuff, at least as far as I know, and I don’t know everything ;-) 

Thank you Hasmarto. I'll check it out.