When I re-tubed I went with all JJ's, I got a really good rock tone, powerful bass, creamy mids and smooth highs with no harshness, perfect for Gilmour Wall tone, perfect sorrow with no Muff. What I couldn't get was a passable Fender twang tone for my teles. I then got some Tung-Sols 12AX7's and they were dreadfull, the bottom end just disappeared, had to turn the bass full up and still no thump, JJ's and Tung's don't play nice together. In v1 I now have a JJ ECC803, this is a very high gain factor valve that breaks up in the highs first giving me some raspy grit. v2 Electro Harmonix 12AX7, together they are perfect for my Fender tones with huge amounts of bottom end. v3 is a Electro Harmonix 12AX7 but thats paired up with a JJ ECC82, drops the gain down to put channel 2 into AC/DC mode but now as you turn the gain up you get a creamy sustain without the modern Egnater tone, spandex and the Jem. For v5 Tung-Sol 12AX7. The Phase v6 I'm torn between a JJ 5751 and a Electro Harmonix 12AX7, because the Renegade is so loud you can get away with the 30% drop with the 5751 and still crank out gig volume but the Electro is so easy to drive into break up that the Renegade will sing at a lower volume....I think the Electro is the perfect guitar amp valve. For the power tubes I went with JJ again, the E34L matches the 6L6 in volume perfectly. KT-77 have a tone that's a mix of EL34 and 6L6 but we have the MIX knob to dial that in....but putting quads in really makes no sense....I've been Dr Sheldon Cooper and this has been "Fun with Valves".