Sample Rate Matching from M2 Mac Mini to DAC

[Dbturbo2]

@Agoldnear

@Agoldnear

With Power of Two enabled the MPS-5 sample rate showed 384k regardless of the sample rate being played.

This is a tell-tale… You should see in the Audirvana playback screen, that a 16/44.1kHz source file being output at 24 or 32bit/352.8kHz…

I retried the Power of Two and got a 16/44,1 file to update the MPS-5 display to 352.8, and the sound was normal speed with no distortion. When I changed the source file to 24/48, 24/96, or 24/192 the sound was normal speed but with audible distortion for each of those 3 sample rates.

I’ve always been under the impression that all Playback Designs platforms converted all PCMxxx to DSD by nature of the DAC design and played DSD natively or via DoP…

Correct, all files are upsampled to double DSD

In any event… When you say that the MPS-5 does not update to sample rate changes, are you also saying that you do not get output (sound)? Or, are you able to listen to music, but the MPS-5 does not display the sample-rate?

In a nutshell, if the displayed MPS-5 sample rate does not match the sample rate output from AS/Audio MIDI then there is no sound output. So to get any file to play with normal sound output, I have to play a file that matches the displayed sample rate. If I choose a file with a sample rate different than what is displayed, I have to either power cycle the MPS-5 or choose a different source input and then cycle back to the USB-X input.

Try updating the Mini to macOS Sonoma 14.3.1

Completed

What does Playback Designs say about the behavior you are experiencing?

I have not yet contacted them, I was trying to rule out issues with either my setup or AS beforehand. And since Roon was operating properly, it seemed possible that the issue might be settings or software related.

Thanks

[Agoldnear]

It seems we are at a point to have @Antoine investigate why this is happening in Audirvana and get some feedback from Playback Designs…

Thanks for your willingness to go through the paces in-order to uncover a solution… not everybody is so willing to do so…

[Dbturbo2]

Appreciate all of your help and time, thank you!

[Antoine]

@Dbturbo2

Stream ID 0x6d 2 channels starting at 1
16 virtual formats:
2 ch Mixable linear PCM Interleaved 32 little endian Signed Float 384kHz
2 ch Mixable linear PCM Interleaved 32 little endian Signed Float 352.8kHz
2 ch Mixable linear PCM Interleaved 32 little endian Signed Float 192kHz
2 ch Mixable linear PCM Interleaved 32 little endian Signed Float 176.4kHz
2 ch Mixable linear PCM Interleaved 32 little endian Signed Float 96kHz
2 ch Mixable linear PCM Interleaved 32 little endian Signed Float 88.2kHz
2 ch Mixable linear PCM Interleaved 32 little endian Signed Float 48kHz
2 ch Mixable linear PCM Interleaved 32 little endian Signed Float 44.1kHz
2 ch Non-mixable linear PCM Interleaved 24 little endian Signed Integer 384kHz
2 ch Non-mixable linear PCM Interleaved 24 little endian Signed Integer 352.8kHz
2 ch Non-mixable linear PCM Interleaved 24 little endian Signed Integer 192kHz
2 ch Non-mixable linear PCM Interleaved 24 little endian Signed Integer 176.4kHz
2 ch Non-mixable linear PCM Interleaved 24 little endian Signed Integer 96kHz
2 ch Non-mixable linear PCM Interleaved 24 little endian Signed Integer 88.2kHz
2 ch Non-mixable linear PCM Interleaved 24 little endian Signed Integer 48kHz
2 ch Non-mixable linear PCM Interleaved 24 little endian Signed Integer 44.1kHz

16 physical formats
2 ch Mixable linear PCM Interleaved 24 little endian Signed Integer 384kHz
2 ch Mixable linear PCM Interleaved 24 little endian Signed Integer 352.8kHz
2 ch Mixable linear PCM Interleaved 24 little endian Signed Integer 192kHz
2 ch Mixable linear PCM Interleaved 24 little endian Signed Integer 176.4kHz
2 ch Mixable linear PCM Interleaved 24 little endian Signed Integer 96kHz
2 ch Mixable linear PCM Interleaved 24 little endian Signed Integer 88.2kHz
2 ch Mixable linear PCM Interleaved 24 little endian Signed Integer 48kHz
2 ch Mixable linear PCM Interleaved 24 little endian Signed Integer 44.1kHz
2 ch Non-mixable linear PCM Interleaved 24 little endian Signed Integer 384kHz
2 ch Non-mixable linear PCM Interleaved 24 little endian Signed Integer 352.8kHz
2 ch Non-mixable linear PCM Interleaved 24 little endian Signed Integer 192kHz
2 ch Non-mixable linear PCM Interleaved 24 little endian Signed Integer 176.4kHz
2 ch Non-mixable linear PCM Interleaved 24 little endian Signed Integer 96kHz
2 ch Non-mixable linear PCM Interleaved 24 little endian Signed Integer 88.2kHz
2 ch Non-mixable linear PCM Interleaved 24 little endian Signed Integer 48kHz
2 ch Non-mixable linear PCM Interleaved 24 little endian Signed Integer 44.1kHz

Hi @Dbturbo2,

If you look at your device formats, it doesn’t state it supports 16 bits, hence why you always see 24 or 32 bits being played to your track.

All that Audirvana does if it changes bit levels (16 to 24, or 24 to 32) is “zero padding.” This just means putting zeroes in the lowest bit registers. It doesn’t affect anything, any more than writing “1.00000000” instead of “1” affects the quantity. And neither does the reverse, such as when a 24-bit device is in the chain - that’s just changing “1.00000000” back to “1” again. No dither involved either way.

[Agoldnear]

… When I changed the source file to 24/48, 24/96, or 24/192 the sound was normal speed but with audible distortion for each of those 3 sample rates.

What is displayed when you play these 24 bit files without up-sampling enabled? Do they play normally without distortion?

[Dbturbo2]

Appreciate the clarification on that, thanks Aintoine.

[Dbturbo2]

@Agoldnear

… When I changed the source file to 24/48, 24/96, or 24/192 the sound was normal speed but with audible distortion for each of those 3 sample rates.

What is displayed when you play these 24 bit files without up-sampling enabled? Do they play normally without distortion?

Yes they play normally without distortion.

[Agoldnear]

It’s possible you were hearing overload clipping distortion as a result of too much gain from the upsampling processing of 24 bit files… You probably will need to lower the output volume of Audirvana by at least -6dB, in this scenario…