PHONO PREAMP

Stay away from those phono  stage using 12au7s. High end tube gain stage should not use those cheap tubes w/ high output impudence and non-linear gain. High mu tubes may not Sound smooth as directly heated tubes, but at least be able to drive equalizer network w/o too much variance. Also, the real cost no concern phono stage should use inductors in equalizer.

Stay away from those phono  stage using 12au7s. High end tube gain stage should not use those cheap tubes w/ high output impudence and non-linear gain. High mu tubes may not Sound smooth as directly heated tubes, but at least be able to drive equalizer network w/o too much variance. Also, the real cost no concern phono stage should use inductors in equalizer.

I can't agree with this.

First, the 12AU7 is based on the 6SN7 and has similar linearity. Their main problem (which is not an issue with 6SN7s) is microphonics. They are not particularly 'high output impedance'; in fact are often used to drive power tubes.

Inductors say nothing about phono EQ one way or the other. One issue with using inductors in a phono stage is ringing; this calls for careful design to make them work.

@rhodes Have you considered using a balanced phono setup? All cartridges are a balanced source and it sounds like you have an amplifier that has a balanced input. An advantage of balanced operation is the effect of the interconnect cables in the system sound is reduced. 

Thanks for the tube info.

Btw,atmaphere amp sucks: its output impedance is so high that only speaker has reasonable punch driven by those type of otl amps is eletrostatic speaker. Furthermore ,even after extentive mod, atmaphere amps longtail differential driver stage is too weak (guess which tube number is the dtiver tube :)).

The world is your oyster my friend - you have a brilliant choice out there:
for tubes:
1. Tron
2. Thoress
3. Aesthetix
4. Manley Steelhead
that's just four

Solid State:
1. Whest Reference
2. Tom Evans Groove Master
3. Moon Audio (not sure model name - but amazing SN ratio)
4. Pass LAbs
5. Van Den Hul (the grail I think)

you are gonna have to speak to dealers and ask if you can borrow one to plug into your system and listen for about a week or so. You are shelling out a lot of cash so enjoy the journey so to speak. If you have a lot of pre 70's records look for a stage with adjustable EQ.