I found this little DAC online and found some good commends in diyaudio.com. I was looking for a 24/192 DAC, but needed something to hold me over until I found the right DAC. My old DAC was hampered by the USB to SPDIF device's 16/44 limit.
Here is the info from hifimediy.com:
"HifiMeDiy Sabre USB DAC. 96khz/24bit - ES9023+TE7022 + USB to optical converter
This small and simple dac uses the ES9023 dac chip from Sabre with SABRE DAC technology. It's is a quite new chip that features outstanding audio quality in a simple implementation. The ES9023 dac chip has a driver built in which outputs 2Vrms line level signal,and are able to drive low impedance loads like headphones, but at 32ohm the output power is reduced to 1Vrms, so connecting to an amp/preamp is recommended if your headphones are low efficiency.
The LT1763 low noise regulator is used.
Output on 3.5mm headphone jack. New batch has a bonus feature: the ouput also acts as a optical output if you plug a optical cable in place of the normal 3.5mm cable. So this device can also act as a USB to optical converter.
This DAC chip does not have any DC voltage at it's output, eliminating the need of a DC coupling capacitor at the output.
With patented HyperstreamTM architecture and Time Domain Jitter Eliminator, the ES9023 delivers jitter-free studio quality audio with 112dB DNR.
With this DAC we combined the Sabre DAC chip with the quality Tenor TE7022 USB receiver. It accepts up to 96khz/24bit input signals from USB, and it will upsample lower input signals to feed the ES9023 dac chip with 96/khz/24bit signal. This makes it possible to get a great dynamic range of 112db. (in case a 16 bit receiver like pcm2706 were used it would have been limited to 96dB.) It responds to changes in system volume control (on MAC with volume hotkeys). No drivers required for Windows, Mac and Linux."
Description: The small black matchbox-sized plastic case has 3.5mm jack with a red light emanating from it with a 3" USB cable. There are no other physical features to the unit. After putting a ferrite collar on the USB cable, I plugged in Win7 recognized it within a moment. I restarted Foobar and it worked. Very simple.
Impressions: While I did not compare it to another DAC, the sound is excellent. Strong bass, nice air and smooth treble. Female vocals are particularly nice. On classical, I noted a hint of congestion on crescendos, but well articulated otherwise. Certainly, not a deal breaker. I was able to pickup small background sounds better than my previous DAC+USB converter. I would say the mids are slightly forward, but not unpleasantly so. I listened to bassy dance music, blues, jazz, classical, and rock. Mostly redbook ALAC/WAV files with some hi-rez FLACs.
Issues: Some have reported noise, and recommended a USB isolator. On my rig, it was quiet at my fairly loud music levels. However, at max volume on my 5 watt Vincent HP amp, I did note some noise on my HE500 with the music paused. With the volume @ 12 o'clock, the noise was not noticeable. Only at max could I hear it. I connected my Koss Portapros directly to the 3.5mm jack and it was dead quiet. Likely, it is the tube stage in my amp. It was fine for me, YMMV.
All in all, it was well worth the $52 (delivered) I paid.