Best DAC from $1500 to $2500 (or so) Can anything beat the Eastern Electric Minimax? - Page 13

Quote:

Originally Posted by Currawong 

That is what you are paying for the $3k+ DACs anyhow: A much better digital implementation. It just happens to be in the box and not outside it.

Well no, the DAC has no transport functions and even after taking the SPDIF stream the original transport created and putting it through a hopefully better (without knowing the jitter of before and after its a guess that its helping) reclock, its still on the DAC to accept the stream and use its clock going forward.

Back in the day Monarchy Audio pretty much made its name selling such boxes but when people actually stopped to measure... in many cases it made things worse.

So for me the idea that a feature limited external USB soundcard can improve on the internal PCIe soundcard while being smaller and in most cases limited to USB power is silly.  Measurements or it's snake oil.

Which is not to say it won't make a difference.  It will be, but is it better metrics wise?  Something I need to take a look at... again :D

Not sure what happened there :p

Looking into the new crop, so far with no exception, even the best USB>SPDIF adapters, Audiophileo included, are at best moderately better than what they are plugged into.  Ie if your Apple laptop has 400ps of jitter, the jitter after would be at best in the 390ps range.  Connect to something with a silly 4ns and it'll come down to 3.9ns.  In a lot of cases it gets worse.  I'll keep looking for the exception but so far at best a USB>SPDIF adapter should be considered only if the transport has no SPDIF out to begin with.  The other thing I noticed is the big change from one to another is the case, internally most use the same ICs to get it done.  I haven't found measurements for the M2Tech or Stello options so... back to research.

How about the OffRamp - 5 as the transport?

As luck would have it its the only one Stereophile didn't compare to straight SPDIF but...

The Audio Precision calculated the level of jitter to be just 343 picoseconds peak, over a 50Hz–100kHz bandwidth. For reference, the BNC version of the Halide Bridge's S/PDIF output produced 440ps peak measured over the same bandwidth (footnote 1); the Musical Fidelity V-Link's output measured 395ps peak.

One thing to keep in mind is numbers are only useful when comparing the same site.  Stereophile and the other site that does measurements had wildly different numbers.  I believe the other site used pure tones from a 'perfect' source while Stereophile uses real world sources.

Another data point  Stello U2 not U3...

By contrast, both the Lindemann and Stello converters (with their volume controls set to do nothing) gave significantly lower levels of datastream jitter: 444 picoseconds (0.444ns) and 395ps (0.395ns), respectively, and their eye patterns were open and well defined.

Steve claims that the regulated output of the Off-Ramp 5 is somewhere around 170ps P-P.

I think how the test is done, and what drives it has more to do with the result than anything.  Audiophileo claims 2.6ps which is shall be say likely measured internally and not externally ;)  The one review I found that measured the A2 put it in the same class as the Halide.  Better in one area, worse in another.

Quote:

Originally Posted by Solude 

I think how the test is done, and what drives it has more to do with the result than anything.  Audiophileo claims 2.6ps which is shall be say likely measured internally and not externally ;)  The one review I found that measured the A2 put it in the same class as the Halide.  Better in one area, worse in another.

Yes, there's some way to tap into its output stream which is how they get those measurements. A Simaudio Moon 750D was measured at 75ps from its S/Pdif output. The idea that the Audiophilleo is 20X better than that is silly.

Solude: 

http://www.hi-fiworld.co.uk/index.php/internet-audio/486-usb-to-spdif-convertors.html

Listening tests followed by measurements.

That's the one I referred to.  The key here is using that method the Halide got 60ps combines jitter while Stereophile measured it at 440ps.  So if the Audiophileo got 58ps my guess would be a Stereophile measurement of around 425ps.  The other thing I found is that SPDIF receivers are designed to drop the jitter while they do their thing.  So if you feed receiver X 425ps of jitter the output into the DAC will be closer to 21-42ps.

The one I want to find numbers on is the AudioGD one.  The DSP model does the whole PS Audio NativeX thing of buffering and reclocking the data without changing it before sending it out.  That it has a clock upgrade doesn't give me warm and fuzzies though.  Given what it is, it should only have the option of the best clock.

Fair enough. Some of it may relate to the S/PDIF output, not just jitter. Upgrading the AP1 with better power, first using the Vaunix hub, then the Pure Power definitely made a difference. That correlates with a comments from a couple of engineers along the lines that even if the jitter is low, the quality of the S/PDIF signal output is still important.

Anyhow, it has been interesting pondering the possibilities of high-quality USB input both integrated and separate from a high-end DAC. If I were buying from scratch now I'd take a chance on the NAD.

SPDIF Jitter (clock phase noise)

This really only affects sound of the signal going directly to a DAC. If you're running into a computer, the computer is effectively going to be reclocking everything. Same applies also to CD-recoders, DAT tape decs and similar devices. Even modern DACs have typically a small buffer and reclocking circuitry, so the jitter is not so big problem nowadays that it used to be.

Quote:

Originally Posted by Solude 

That's the one I referred to.  The key here is using that method the Halide got 60ps combines jitter while Stereophile measured it at 440ps.  So if the Audiophileo got 58ps my guess would be a Stereophile measurement of around 425ps.  The other thing I found is that SPDIF receivers are designed to drop the jitter while they do their thing.  So if you feed receiver X 425ps of jitter the output into the DAC will be closer to 21-42ps.

 

The one I want to find numbers on is the AudioGD one.  The DSP model does the whole PS Audio NativeX thing of buffering and reclocking the data without changing it before sending it out.  That it has a clock upgrade doesn't give me warm and fuzzies though.  Given what it is, it should only have the option of the best clock.

Quote:

Originally Posted by complin 

Even modern DACs have typically a small buffer and reclocking circuitry, so the jitter is not so big problem nowadays that it used to be.

Yup :D