Best Tubes on Market today?

If the transformer noise is physically coming from the transformer itself then it is DC offset and can be eliminated easily enough. You can try turning things off until you find the culprit, or just buy a DC offset eliminator. 

Tubes themselves are so highly variable you can pay a fortune and still get crap or you can go cheap and pray they last forever they sound so good. I've rolled more than a few and while yes they do make a difference the difference they do make is tiny in the extreme. If you want better sound skip the tubes, get a better amp.

Regardless which way you go on that one tubes can be noisy but I have yet to hear one hum. Usually its a faint whoosh or more often a crackle that sounds like static but either way comes and goes never just steadily going on and on. So anything like that I would be looking elsewhere, like the DC offset, or hum from a ground loop getting in there somewhere.

RAM Labs.

DC offset? How do I test for it? I get the transformer buzz even when everything is disconnected. Not sure what you mean, please elaborate. 

Better amp than Mastersound ? I was under the impression mastersound is one of the more high end amps out there. It's counterpart PF100 is $50,000 and a slightly larger Evo 845 is 18k. 

I switched pre tubes around from left to right and the louder noise also moved to the other channel. So I assume it's pre tube. How do I get rid of ground loop? 

Also, my questions remains, what are the best 845 tubes right now? 

@millercarbon: DC offset only applies to transistor amps. It is measured in millivolts. Tube amps do not have DC offset. Output transformers do not pass DC voltage. Regarding AC power lines, I doubt they have any DC voltage on them!