Head-Fi has at least a couple threads about this amp, go here for the thread Ray Samuels started, and here for other comments. I got my Protector on 3/11 and have been burning it in 24/7 with the Isotek cd, and hopefully will have plenty of time on it for critical listening this coming weekend (HD650s, AKG701s). FYI - unit is wicked small, blown away by the miniaturization of some audio components nowadays.
Finally got my HD650s running on this amp in balanced mode, and I have no intention of going back to single ended.
Had a friend on another forum reterminate with XLRs my Stefan AudioArts HD650 cable; he used a bit of the AudoArts cable to make a Protector->XLR balanced adaptor, too. Got in a few hours of burn in over the past two days and some listening time, too. Balanced output from this amp is clearly superior to my ears. My HD650s never sounded this good. Great pairing between amp and phones, for sure, in balanced mode. More air around and improved positioning of voices / instruments, improved midrange, gobs of detail, tuneful bass, more realistic orchestral instrument sound-presentation-presence, etc. I know it is only a limited amount of time running the amp balanced v. tons of single-ended burn-in time that I did previously, and that more burn of the reterminated Stefan AudioArts cable and custom adaptor as well are to come. However, I cannot help but like very much what I heard over a few hours of work yesterday and today. I note that things also have improved from yesterday's listening session, too. I look forward to some more 24/7 burn-in over the weekend with the Isotek disc, coupled with listening using even better sources. I note the amp has no problem holding its charge, too. I anticipate it will now be most unsatisfying to listen in single-ended mode to my other headphones - darn hobby.
