I spent some quality time, over two days, with the hd800 + hdvd800 and hdva600 at the tokyo show recently. Truly awesome. Right up there with the Luxmans that I was scurrying back and forth between, trying to A-B. The sennheiser`s source was 16bit modern vocal jazz out of an unseen CD player, in balanced mode with Senn`s new 4xlr cable, which is also very nice - very light xlr. I wasn`t able to A/B the supposedly weak DAC in the hdvd800 with the 600, because of the single source for both amps. The senn guy told me the amplification in the 600 and 800 are identical. I would go for the 600.
Of course, neither are as good as my Andix.
Edited by Dopaminer - 11/9/13 at 9:16pm