Wanted to add my tube rolling experiences from yesterday ... My build is Crack + Speedball with Alps Blue Velvet pot and Obbligato 70uF Oil Film coupling cap upgrades. Headphones are DT770 250 ohm.
Driver:
Unbranded Chinese 12AU7 - Harsh & cold, worst of the bunch!
EH 12AU7 - Dark & lacking detail
JAN 5963 (came with) - Not bad but also not the best, good middle road tube
RCA Clear Top - Treble bright & lacking bass
Philco 12BH7 - This is the third best tube heard ... ~ equal to Mullard
Brimar (Mullard) 13D5 - Second best, lots of detail, good bass extension, best midrange of all tested
Telefunken 12AU7 - The best of the bunch! Very balanced across freq curve, excellent detail and good bass extension
As for the 6080:
Raytheon 6080WC (came with) - Not bad, again, middle road tube
Mullard 6080 - WOW! The depth and richness of the sound is incredible. It was like a veil was lifted. The bass is much better and deeper/tighter. Detail is incredible! You can hear sticks hitting percussion and fingers on strings.
The verdict for me is Telefunken 12AU7 driver and Mullard 6080 ... enjoy the tube pr0n pic: