Anyone tried the Benchmark

I have the HD-650's and had the Benchmark DAC. I also used the DAC-1 with my Krell KAV-400xi/Dynaudio Contour S3.4 speaker setup. FYI, Head-Fi.org has a ton of info about the headphone pairing with this DAC and others.

What I can tell you about my experience is that I didn't care for the sound. To me, it was harsh, analytical, forward and cold. My opinion applies both to the speaker setup and the DAC-1 directly driving the HD-650s. Sources I used were Sonos ZP-90, Apple Airport Express and my MacBook Pro digital out - admittedly not the greatest "transports" but I always used lossless files. I went to an Electrocompaniet EMC-1UP CD Player and wow, what a difference - warmer, definitely, but a much more realistic and enjoyable experience. I sold that and went to the ECD-1 DAC, which is basically the digital section of the EMC-1UP, and it still sounds great, but lacks the smallest bit of extra magic as compared the single-box CD player - probably attributable to jitter from the Sonos, cabling, god-knows-what - but it's still much better to my ears and in my system than the DAC1 ever was.

You can always try out the Benchmark. The upside is that it has decent resale value and you won't lose much, especially if you buy used to begin with. If you like it, that's great because they are not super expensive.

I've had a few headphones in the same category as the HD650's, such as the Sony MDR-CD3000 and SA5000, the AKG K701 and some Beyerdynamics. The 650's remain my favorite so far, just make sure you burn them in for a LONG time as they did not sound that great out-of-the-box. In fact, I almost returned them in the beginning. I don't want to try the HD800's because I'd probably have to pick up a pair if I do, so I'm content in my ignorant bliss.