A T2 is the only amp I've heard truly wake up an O2. I don't have them anymore, though; I might've kept 'em if I'd planned on getting a T2 at that time.
Man, seeing those BugelBoy 6DJ8 in that excellent Kerry build reminds me there's a whole world of input tube rolling to explore.
@Whitigir - any recommendations here? I have a couple of NOS variants floating around, but nothing special. Still running the Japanese 7DJ8 georgep shipped the amp with - no complaints at all about their sound...until I find better!
For EL34, I'm now liking the Holland brown base xf4/xf5 EL34 best so far. Better than the British Mullard xf3, which just give up a little bit too much energy up top. The Hollands are just so well balanced from top to bottom, superbly detailed, neutral, musical, and smooth. But the Russian Mullards are still great for the money and well balanced; really impressive - mostly it's just noticeable that they're a little less smooth versus the Hollands. The other downside of the Hollands, besides price/sourcing, is that those brown-bases clash with the beautiful uniform blackness of the T2!
This amp is still almost life-changing good. The magic simply doesn't wear off.
@georgep