>rob80b: Thanks for the information - I'll continue reading/searching through head-fi.
Regarding the difference between hi/low gain - well, I am not an experienced listener, most probably half-deaf (due to age and noisy work environment), but I my impressions are same as R.Daneel's:
On high gain, even with voulume turned down to more-or-less match low gain levels HD800 sound more dynamic, agressive, even harsh. Too dynamic, too harsh for my taste. Thats still with non-balanced connections as mentioned earlier.
It does not happen with low gain - even at max volume level, it is much calmer, smoother sound. Perfect match for me.
More like class A amp sound.
Well - maybe that's the case: not sure if BHA-1 goes class A all the way to max, or maybe it switches to A/B above certain levels (high gain)?