Tube amp forethought

SSD ?

nos tubes sound better have a lower noise floor and last longer than modern tubes
i see people get pricey tube gear and leave the chinese/russian mediocre tubes than they preach to swap every year scared of them to fail (ps audio)...
some modern amps like the schiit freya comes from the factory with microphonic tubes and people think it's part of the magic .(it actually is because all tubes are at least a little microphonic but those stock tubes are really crap ,the darkvoice 336 has a hum in one channel and people live with it) 
once you get the amp let it settle for a couple of weeks  with the stock tubes .then try to make a judgment about the sound what is missing or too much .than swap'em all without looking back for nos (made in uk,usa,germany or holland) with the sonics that you would like to add.i like mullard tubes ,ge's are nice as well .enjoy!

Room size, music taste, budget, near field, hearing? 

Room size: 13’x19’x vaulted ceiling
music taste: LarryCarlton jazz, SteelyDan, i will begin dabbling in some classical
near field: speakers will be 8’ from LP
Hearing ??? My hearing roll off at 14Khz

When my original version Freya arrived a couple of years ago with its stock "mystery tubes" (actually NOS Russians) they were very quiet, and displayed no microphonics. Hardly crap. I ordered a set of new version Tung Sols anyway and they sounded fine and very quiet but I wondered if NOS anything else would sound better. I eventually bought bunches of NOS Sylvanias and GEs, and decided the GEs were a little more to my tastes. Note that all of the tubes I mentioned sounded and performed fine, no microphonics or noise, just slight tonal differences as one would expect. The various Russian power tubes I've used in both my previous push pull and current single ended power amps have performed brilliantly, and really lasted...KT88s, 120s, 77s, 6550s, etc., including my current faves 7581As.