Hello all. I was a participant in the 10 April 2010 USB DAC Shoot-out. Here are my thoughts on each DAC with a ranking of each at the end of the review. The DACs were, in alphabetical order, the Ayre, dB Labs, Onix, PS Audio, and an inexpensive USB DAC whose name I cannot recall. Please note that I was not completely familiar with the cost of the various DACs until after the Shoot-Out was completed.
As background, my personal tastes lean to Vinyl (and Reel to Reel player at work!), and I use a Lite-on DAC 60 with GR-Research Step 1 mods, GR-Research O-3 speakers (and occasionally my Soliloquy 8.1 speakers), and a PC with Xonar HDAV sound card as the SPDIF digital stream output, Dodd Audio pre-amp and either my Belles Hot Rod amp or Chiro C-200 amp.
Danny can provide better specifics, but with the exception of the PS Audio, all DACs were tested using a Mac Mini outputting a digital stream and connected to each DAC with a USB cable. The same power cord and cable was used throughout. However, the PS Audio was tested as a DAC/Transport combo connected with an HDMI cable. The PS Audio DAC was also tested separately using its USB digital interface to provide a more fair comparison to the other DACs.
Ayre: The Ayre had a good top to bottom balance with "the best of the bunch" harmonic undertones. It was very musical with a tendency toward a "laid-back" sound. It had a rather nice balance to its sound reproduction. The female vocal, as provided by Diane Warren was, to me, a bit too forward in the aural presentation. Some upper midrange sounds had a small touch of forwardness and were very slightly "digital" sounding. Instruments were presented a bit more crowded together than the dB Labs. It had a slightly veiled sound which would not have been noticeable if the other DACs had not been present as a comparison. Overall, I found it to be an enjoyable and easy to listen to DAC.
dB Labs: The dB Labs DAC had very crystalline highs, perhaps the best that I have ever heard from 16 bit music. The sustain of the instruments was very good. The sound was clean with a nice wide soundstage. The DAC had a very open sound that was slightly "laid back" and the bass region was nice and taut. Overall the sound had a nice analog character. In the most distinctive difference of all the DACs, using the music of artist Jack Johnson, the DAC excelled in reproduction of the natural-ness of the male vocal. The soundstage depth was slightly shallow compared to the PS Audio DAC/Transport solution using its HDMI connector to connect both the Transport and the DAC.
Onix: The Onix was a better than average DAC, with a slightly strained sound and presented itself as a little fuzzy or veiled sounding. It was smooth except in the upper mid-range which I found to be a bit too aggressive for my tastes. The soundstage was flatter than the Ayre, dB Labs, and PS Audio and I thought that it was a very good value as long as you had speakers that provided a more "dark" presentation. It was definitely worth looking into as a very good value for its price point. Personally, it is not a DAC that I would purchase, but given the right system it might be fine for others.
PS Audio: The PS Audio was tested two ways, one as the company preferred Transport/DAC combination and one using the USB input of the DAC driven by the Mac Mini setup. Firstly, the DAC/Transport combination with HDMI connection had the deepest soundstage of the DACs. It also had a relatively narrow soundstage in that setup which was localized between the two speakers and, oddly enough, did not make the speakers "disappear" in the room. The bass was slightly tubby and bloated, but was not un-enjoyable and I am certain the younger audiophiles used to the bottom heavy songs of today would enjoy its low end presentation more than the other DACs presentation of similar material. The second test of the PS Audio, using only the DAC with the USB instead of HDMI input, presented itself quite differently. The soundstage was less deep, but it became significantly wider with instruments being spaced further apart and less "stuck together." The bass became a bit more loose than it had been and female vocals became less forward sounding. The mid to lower mid-range sounded very good indeed. I preferred the sound of the Ayre and dB Labs highs as compared to the PS Audio in either of its configurations. I definitely preferred the sound of the DAC by itself and not conjoined with the PS Audio transport. I would definitely be interested in hearing the PS Audio DAC being driven by an ASUS Xonar HDAV 1.3 Slim PC Audio card (I do not use Mac computers - "I'm a PC"). The Xonar Slim has HDMI output capabilities and I wonder if there is any difference between the PC sound card and the PS Audio Transport.
USB DAC: I personally did not care for this DAC. I found it to be too aggressive and "digital" sounding for my tastes. If used with computer system speakers and at a rather low volume for recreational listening perhaps it could be useful, but I found the sound too irritating for my ears. I believe that I am the only one who had this opinion of the DAC, so take that as a lone voice in the wilderness.
Conclusions: As ranked in an order of personal preference, I would rank the DACs in the following order: dB Labs, Ayre, PS Audio, Onix, and the USB DAC. I felt that the dB Labs and Ayre were rather close in sound with the edge going to the dB Labs and both were better than the PS Audio by a small but noticeable amount and that the Onix was above the average in its price class (though not in the same class as the first three units) with the USB DAC trailing a good ways behind the others. I found the PS Audio setup to sound better in a Mac Mini computer-fed USB interface configuration rather than the DAC/Transport combination recommended by PS Audio.
