Mostly a Lavry DA10, though recently also a Rega RP1-TTVJ stage. My B22 is indeed a two-board version (I previously had a four-board, though eventually was told by next owner there were problems with it - can't remember what - and it's been years and different gear). I should clarify my issues - I tend to feel over time all wire-with-gain amps I've had (B22, GS1, CK2III) are bright, and only used successfully over time with dark cans such as the lower Senns. The HD800 was the first to push the Luxman there too, which is another story. Course brightness means different things to different people and often I just mean a perceived imbalanced towards the top. And I'm obviously shifting blame away from phones to the amp, a little unfair. It's just less often and less severe with the P/V than my other amps.