Thanks for sharing your experience! As you say, music can stir the soul and I feel the amp helps to do it. Now that you mentioned it, I have to listen to Anouar Brahem again. The three ECM records I own are all great, the standout for me being „The Astounding Eyes of Rita“ – what a gem and great evening listening. I find myself drawn more and more to this kind of music, which conveys a sense of relaxedness, soulfulness, experience. The style is not that important, it can be this, it can be rock music (I adore Yo La Tengo), ambient, classical or other. I guess it´s a good sign this speaks to me and I don´t need cathartic relief as often as I used to. But a well recorded wall of sound is also no problem for the R800i.
This tube rolling sure is a black hole thing. I´m far from having that many tubes and I´m very happy with the tubes I own but I keep my eyes and ears open to what people say sounds nice and every now and then get something new (or new old).
For now I´m really happy with the Teles but some local audioguy came across a box of unused RFT ECC83s, I´m curious how they perform. And there´s still Brimar, Valvo and Mullard to check out. But I´m not in a hurry with that.
I did try the Mullard 12AX7 (CV4024) but I didn´t find it to be very engaging so I´m not following that route for now. (I always have to say „for now“ when it comes to these things, I know myself...)
In the 6SN7 slot I´ve lately been using Sylvania VT-231s and wow, they are really good. They are military GTs (I think) and are supposed to sound a lot like the regular GTs or the well-regarded GTAs. So, yes, I agree, they´re really, really good. Also there´s a variety of Fotons with a squareish getter that extends in a right angle that is supposed to be a tad better than the regular ones. I own these and tried them, they sound nice, but I have to find the time to do another direct comparison. With the prices for NOS these days the Fotons are a high quality bargain and the right angle-getter ones also don´t cost a fortune (I paid about 30€ for a pair).
The Svetlana 5U4Cs with black paltes have become a kind of sensation and I´m also very happy with the ones I own. They just don´t seem to last very long, I read about quite a few giving up after just a few hundred hours. One question: Does yours light up a bit when you start up the amp? I read contradictory things about that: Some say it´s a sign they are on their way out and you should replace it soon while others say it´s part of the show. My current one does does show something like a tiny blue flame for a brief moment, but it´s done this almost from the beginning and it´s running fine. Maybe I´m playing with fire, who knows.
All the best!