Wanted to provide some feedback on the HPA in this thread (had left some in one of the other related threads but will add it here as well). I've now had the HPA burned in for about 250 hours (most of it with XLO Ref burn-in or Purist Audio Design burn in tracks; music when I'm listening to it). It goes without saying that I love the HPA!
I'm using with an iMac with playback via iTunes + Amarra in my home office. Revelation Audio Cryo USB cable. HD800's and will receive a pair of MarkL LA7000's any day now and look forward to that pairing as well. The sound is really great with the HD800's, and that's with the stock cable. I was about to send the HD800's back for giving me migranes, but after using the HPA I am now able to listen for a long time without getting a headache (here I thought it was the weight of the headphone and in hindsight it was more likely the fatigue from the sibilance the prior setup was generating, which includes a couple big name DAC's). Big evolution in the HPA over the 250 hours, and really love the sound. Great detail, extension, imaging, musicality, silent background, analog sound, absolutely LOVE female vocals on this unit. My wife wonders now why I've been building (translate - spending so much time/resources) a hifi system in our living room after listening (!!). Have been listening to 16/44 WAV files (ripped with EAC and stored on SSD), but have a bunch of high res files I'm planning to give it a run on (recognizing it will play 16 bit, but lock into 88/96/176/192) - will do this via a Weiss unit (firewire from Mac; SPDIF to HPA). Will post experiences once I've had a chance to do this.
The one thing worth noting also about the HPA is the ability to enjoy great recordings of lesser sonic quality (we all know there's plenty of those out there!!). The HD800's were menacing/merciless on anything but pristinely recorded and mixed music before the HPA for me, and while it retains its strengths and transparency, the combination is so much more forgiving and I'm finding myself really enjoying music I know I otherwise would be having a difficult time with using these headphones (at least with the other equipment I have and others I was trying them on). The HPA kinda turns the HD800's into an all purpose can from what I was guessing earlier was a more targeted use (no flames pls! just one bozo's viewpoint).
Congrats Vinnie on a great product.... you've got me very tempted to upgrade to the full meal deal.... ) love being off the grid! (I have spent a lot of time and money cleaning up the power in our NYC apartment which is an old pre-war, so you can imagine the situation; so much simpler to go SLA and more effective).
