Alright, as I sadly(? I think my wallet is sadder than I am) part ways with my Vali 2 for my coming Lyr 2, here are my findings as far as tubes are concerned. The following were all $20 or so tubes that I tried, things definately accessible for most people here. I just tried a whole bunch of different easy to find stuff. I will break down my thoughts!
Here is a list of what I tried, in no particular order:
1. Phillips PCC88 (this thing has factory code DJER, but I can't make out any other symbols)
2. 6N1P-EV (Voshkod? Has gold grid, silver shield, two wire getter-1990)
3. Amperex 6CG7 Orange Globe USA (1979 or 73, can't tell)
4.Tung Sol 6CG7 USA
5. Sylvania 6CG7 triple grey plate, silver shield
6. JJ E88CC Gold Pin
My setup was Tidal (master quality when avalible) ---> Topping D10 USB DAC (sabre chip I beleive) ---> Vali 2 ---> HE 400I
On to impressions:
1. Phillips PCC88: At first, I really wasn’t sure what people had liked this tube for. It felt like there was a filter or tin can over the upper mids/treble - it was pulled back but still trying to be detailed. There was still a bit of sharpness to the treble despite this. Then I played some of a band called Tinariwen, a Tuareg group that performs Malian music. They have some amazing guitar distortion sounds and awesome electric bass and WOW-the bass on this thing is so warm and fuzzy. Guitar distortion just sounds so wonderful, and the electric bass notes roll off like honey. This bass performance carries across the board. Still feels like it can’t decide what it wants to be – is it dry and a tad sharp in the upper range, or a nice warm bassy analog sound? The soundstage is just eh-it is there, not bad, not good. Treble is meh in terms of detail and a bit sharp.
2. Amperex “Globe” 6CG7 USA: This is an interesting one. The best sound stage between the PCC88 and JJ E88CC (Teslaish thing) by far, also the most exciting of the 6CG7 family. Great air to the sound, lots of separation and much more depth. Not incredibly warm though. The PCC88 is grungy and growly in the low notes, this exposes the grunge. The only warmth is evident a bit in the bass. People say this thing is kind of “neutral” and I would agree, exception of the highs, which might be a tad forward and bright.
3. JJ E88CC Gold Pin: Not a lot to hate here. The soundstage is eh -- better than the Phillips (slightly) but worse than the Amperex Globe. I think there is more “air” in it than the Phillips, but it is less warm. Maybe it is just my mind playing tricks on me, but it FEELS newer. I agree with what some others have said – it has a house sound to it. Excited maybe. Not the most relaxing sound, but not really too fatiguing. It lacks the strange “s” sound sibilance peak the Phillips and Amperex seem to have. The treble sounds bigger than especially the Phillips. Less overall detail in the high range though than the Vhosh. Sound stage never really wowed me.
4. Tung Sol 6CG7: I really didn’t think this one stood out in any way. I swear, I put it in and went “ehh, back to the 6N1P”. There was nothing about it that stood out against the Amperex, and it lacked the fun house sound of the Phillips or JJ. I threw it back in for a second time today and found it a bit better. Probably the easiest to listen to of the 6CG7s, being less boringly neutral in the highs than the Sylvania, but less sharp than the Amperex. If I feel like it, I might revisit this one later and let it burn in for a while, but for now, this is all the info you get. As an aside, a thing I liked more about it than the Sylvania was the soundstage. I don’t love how left/right the Sylvania is sometimes.
5. Voshkod 6N1P-EV (1990-04): When I first put this tube in, I was coming from the Amperex, which I liked at the time. It immediately blew me away. It has some of the warmth of the Phillips, but an amazing kind of “flow” to it. Sounds resonate in a really pleasing way. The top end is incredibly detailed and fun to listen to, while the mid isn’t too forward but rich in detail. The bass is tight but powerful. Soundstage is wonderful for this class of tube (6922,E88CC etc.) considering the price and the tube isn’t microphonic at all. It sounds warm and playful and runs warm (glows the most) too! I really love this thing. For the price, you can’t freaking go wrong. I got mine NOS tested from VivaTubes for $5 plus shipping. What the…
6. Sylvania 6CG7 Triple Gray Plate, Silver Shield: This tube was the most expensive, and at first comes off as being neutral as with all the 6CG7s, but I don’t think it is now. It seems natural, but dare I say a dull? Good warm bass, but just flat and flabby. Some people (including Schiit themselves) found that the 6CG7 sounded flat on the Lyr, and I think that might be the case on the Vali as well. The soundstage and the bass is probably the only really redeeming category for any of the 6CG7s honestly – they are all pretty good in that respect. But why this thing when the 6N1P-EV exists for less money? I don’t know.
Bottom line -- best of my tests? Those 6N1P-EVs. Apparently there are even better ones out there than the ones I have. An amazing value. I don't doubt that there are other great options, but that one is a good one when wallet is concerned. It won't make crap sound good though, so be careful. Siblant recordings will sound siblant. Bassless recordings won't have bass.
and sharing your experiences with 12Au7 bottles in the Vali. Salute! 
. But it's bakelite or plastic if that matters.