Phasure NOS1 vs. Pacific Microsonics Model Two

[barrows]

I just wanted to thank you guys for all the information you are providing on Peter's DAC and XXhighend. Although I am not currently in the market for setting up an entirely new front end, I do find Peter's approach to computer playback both unique and fascinating, and I enjoy learning about this unusual approach to digital file playback.

 

[barrows]

I would like to know a little more about the output stage if you are willing to share some details. In general, what type of circuit is used, how do you handle DC offsets, and what gain devices are used (JFETS, MOSFETS, Bipolars, IC opamps)?

 

I still would love to see you develop a DAC which incorporates your oversampling with Predictive Arc, or to license this oversampling code to third parties to use in their designs. With the power available in contemporary DSP/FPGA chips I suspect that this would be possible. This approach would allow people to use any computer, and send the native sample rate to the DAC. I do not doubt that your approach works very well, but it is a little inflexible when it comes to computer choice and interface to the DAC. A DAC with the oversampling built in would be a much more flexible product, and could still allow for programability for different settings.

 

[barrows]

"Purely subjectively."

 

As this is the only relevant criteria to judge an audio component! And this is one person's opinion, of course I am sure if you go to the Phasure forum you can get the opinion's of others. As for your detailed questions, I would suggest that you send PeterST a PM for detailed answers.

Also remember, by nature this DAC avoids SPDIF and operates asynchronously by nature, this fact alone should result in improvements in performance of the PM Model 2.

 

 

 

[barrows]

Ted:

 

"...However, if I understand your last statement correctly (and I probably don't) I will argue that not all asynchronous signal paths are inherently therefore better than a PM Model 2. Heck, we have asynch USB DACs at the $1k level; they are decent but not state of the art just because of asynch operation."

 

No, of course I did not mean to suggest that asynchronous DACs will always sound better regardless of implementation. My comment contained the presumption that both the PM Model 2 and Peter's Phasure NOS are well designed and implemented DACs. And to address Demian's point of a clock linked PM-2 being asynchronous at the same time, yes I agree, to a point. The PM Model still uses SPDIF, and this requires the attendent SPDIF receiver, which I believe it is correct to say, will still add (some) jitter even in a clock linked scenario. (Not to mention the accumulated jitter caused by the clock linking itself, cable losses/reflections, signal transmitter losses, etc.)-inherently, a system using a single fixed frequency clock, adjacent to the DAC chip(s), without having to send that clock anywhere else is ultimately going to result in the lowest possible jitter-assuming equal implementation.

 

Peter: re DC offsets. I was referring to the analog stage, and offsets at the analog outputs of the DAC. This was a round about way to try and get an idea of the circuit design-to deal with DC offsets there are basically three ways: design a circuit which can be carefully trimmed adjusted to have no/minimal offset, this usually requires a somewhat complex circuit. Use a servo feedback loop to eliminate offsets, or AC couple the circuit using caps. My feeling is that each of these approaches has advantages and disadvantages. My opinion is that the lower the offset the better, below 50 mV is good, but I would rather see DC offset in the single digits. I was just wondering about your approach.

 

 

[barrows]

your comments are either ignorant, or just plain inflammatory, and are best kept to yourself.

Equating the cost to produce high end audio products, with that of general consumer electronics is just ridiculous. High end audio products are produced in the thousands, (or in Peterst's case, perhaps a few hundred units ultimately). Consumer electronics are produced in the hundreds of thousands to the millions.

The high end audio industry is essentially a cottage industry, producing small numbers of products at a very high quality, and the economies of scale are entirely different than those of the consumer electronics industry.

 

[barrows]

Peter's DAC is specifically designed to work with his XX Highend PC software, and there are no PCs with Thunderbolt, I think the idea of Thunderbolt compatability with his DAC is somewhat premature.