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[Desertpilot]

As a test of DSD to PCM conversion (using SoX), I used DSP & Output Format, Sample Rate, to play DSD (mostly 64 and 256) at either at "no change" or 192Khz (my pre/pro maximum rate).  With "no change" setting everything resamples to 96Khz using SoX.  With 192Khz selected for all, all files are changed to 192Khz using SoX.

What do forum users recommended?  Is 96Khz a good sample rate (no upsampling) for DSD files?

Thanks Marcus.

[dtc]

DSD to PCM conversion is done at 1/8th the sample rate of the original DSD. So, DSD64 (2.822 MHz) converts to 352 Khz, DSD128 to 705 KHz, etc. It takes less CPU to convert by integer multiples, so I would suggest trying conversions to 88.2 or 176.4, assuming your hardware supports those sample rates.  You probably will not hear the difference between the two or between them and 192, but go with what you like best.

[Desertpilot]

Thanks for your insight!

I think I answered my own question.  I watched "The truth about Nyquist and why 192 kHz does make sense" and "MQA part 1; Why 24 bit 192 kHz audio?" by Hans Beekhuyzen on YouTube.  He argues that 192 kHz is a good choice, in my words, to reduce DAC processing and reduce filtering artifacts.  I will try out all the possibilities.

What a wonderful time to be an audiophile.

Marcus

[dtc]

That video describes exactly why DVD-Audio and SACD were developed. The reconstruction filters are not perfect and cause artifacts in the audio range. Moving the filter to higher frequencies moves the artifacts out of the audio range.  What the video does not address is whether 88, 96, 176 or 192 is the "best" sampling frequency to use.  As I said above, I would try 88 and 176 since it uses less  CPU to convert to them for the DSD to PCM conversion.  And, if you want to upsample 44.1 KHz, again an integer multiple is probably better.  Most PCM DACs upsample to even higher frequencies, so in some sense the exact sample rate you send to the DAC is not relevant, as long as you have not introduced artifacts.

If you want to get further into the details, SACD players also have a low pass filter to filter out the noise you get when converting DSD data. The Sony SACD standard was a 50 KHz filter with a slope of 48 dB/octave.  By default, MC uses a 24 Khz filter with a 48 db/octave slope. That is a very conservative filter and can run into some of the same ringing issues as described in the video. There are also options for 30 KHz and 50 KHz filters, but with slopes of 24 dB/octave. Unfortunately, those slopes are not steep enough to filter out all the noise. Personally, I turn off the DSD conversion filters and use DSP studio to apply a filter like the Sony specification.  The DSD filters can be found in Tools - Options - Audio - Advanced - Configure Input Plug-Ins.

Here are some samples of the low pass filters.

https://yabb.jriver.com/interact/index.php/topic,97740.msg675589.html#msg675589

[Desertpilot]

DTC.  This is awesome information.  Thank you very much.  I am recently retired and have a lot of time to "perfect" my audiophile hobby.  Maybe too much time (hahaha).  I will test what you said.  I do want to restate:  NAS to PC is quick and reliable.  PC (via HDMI) is also reliable.  I am getting great sound from my speakers.  But, as all of you, I am trying to make sure the audio signal from NAS through PC (JRiver) to pre/pro is as "perfect" as I can make it.

Thanks again, Marcus