Spent some time tube rolling this weekend, here are some quick impressions:
1. RCA 6SN7 GT (JAN, 1948) drivers --> Tung Sol 7236 powers: Good balance of detail and euphony, balanced across the frequencies, great soundstage but the mids were notably grainy
2. RCA 6SN7 GT (JAN, 1948) drivers --> Tung Sol 5998 powers: Not a good combo., lost frequency balance, detail and smaller stage, bass was very prominent but a bit loose. Too warm.
3. RCA 6SN7 GT (JAN, 1948) drivers --> Philips EL32 powers: Pleasant enough but a bit anemic, flat sounding. The EL32 seemed ill-suited as output tube in this configuration
4. RCA 6SN7 GT (JAN, 1948) drivers --> Stock Elise 6AS7G powers: Not bad really, but no magic either. Stage width was a weak point and midrange grain reappeared (< 7236)
5. Stock Psvane 6SN7 "UK" drivers --> Tung Sol 7236 power: Enjoyable, great detail and stage but bass light."Solid state" quality, missing out on euphony and warmth, left me wanting more
6. Stock Psvane 6SN7 "UK" drivers --> Tung Sol 5998 powers: A bit warmer than with the TS 7236, decent detail but stage collapsed a bit and highs were brittle on certain tracks
7. Philips EL32 drivers --> Tung Sol 5998 powers: I didn't see it coming but this combination is the surprise winner. There is transparency, pace rhythm and timing that just sounds "correct," It has excellent balance across the frequencies, stage is smaller than 7236 but not constricted and there is air around the instruments that adds realism, emotion and presence. I find that I marvel briefly at the technicalities of Elise's musical presentation with this tube set BUT don't dwell on that as toe-tapping soon takes over.
I am both too experienced at the wallet-unfriendliness of this hobby and too new to tube rolling to think this is my endgame, but I am enjoying it very much. One other perk is that this Elise tube combination sounds excellent and fully engaging at low volumes, a characteristic I've come to recognize as amongst the indicators of quality sound.
Special thanks to
@connieflyer for helping me out. The Feliks-Audio head-fi community is very supportive and populated with genuinely nice, generous people.