I've heard the crack many times. It's certainly better than the Vali IMO. But still, the Vali sounds good with hd600/650. In fact the hd650 is the best match for me. The Vali does not pair well with the he500 and ma900 for me.
kstuart states that he perceives a shift towards more sparkle and clarity after burn in. I'm hearing a bit too much sparkle in the treble pre-burn in. With more sparkle after burn in this would be a real issue for me. The he500 are just too bright and sibilant with the Vali. The ma900 is much too noisy.
I'd be interested in Purrin's impression of the Vali with the he500...sorry if it's already been given.
The hd600/650 is the best match. They are somewhat darker hp's and the sparkle of the Vali seems to be a good balance without become harsh and sibilant.
Thanks a lot! Crack it is then.