Benchmark Dac1 Versions

Bmdduck - USB is safe bet but USB sound is not necessarily better than Spdif. Your plan with serial number is the best think you can do. Ask them what else changed afterward.

One more thing - If you use it with volume control (like I do) disable third position of the switch behind (for instance metal plate allowing only two positions) so that it would not put full amplitude straight to power amp if you switch by accident (cable press against it etc).

Benchmark claims that there have been no revisions in the USB models. I agree with Kijanki on the neutral sound. If I were to take a step up, it would be the Weiss Dac 2 which is a Minerva without the dressing for 3k. If you go with a Benchmark play close attention to your power and power cable. I disagree with Kijanki about not hearing a difference with USB/toslink/spdif. I have heard differences in USB cables and flat out think that toslink sucks compared to the other two, although I have not tried real glass cables.

One other point for you to accept or discard: my Benchmark DAC1 USB opened up a bit when I tried a Furutech power cord. I'm personally a big believer in Furutech products, so I may be hearing what I want to hear. But for me, the improvement was in the 15-20% range...not dramatic, but not miniscule, either.

4est - I'm surprised that you could hear any difference between toslink and coax. Benchmark has few Hz jitter bandwidth and at the frequencies of interest - kHz has in order of -100dB supression of the jitter. Typical jitter artifacts (sidebands) are at about -80dB (but still very audible since not harmonically related to root frequency). Combine two and you'll get -180dB jitter. I cannot hear any difference between Aiport Express with toslink and DVD player with coax but I will try it again. Sound with toslink is as detailed and clean as it gets. People often compare toslink to coax using two devices where one of them is not "bit transparent" (digital volume control, DSP processing etc). I don't dispute what you're hearing - I'm just surpised.

Different DACs, different sources, different cables and they all sounded "soft" or lacking PRaT...