01-13-2024, 05:12 PM (This post was last modified: 01-13-2024, 05:16 PM by Doc77.)
(01-13-2024, 12:13 PM)Tim Curtis Wrote:
(01-13-2024, 10:04 AM)Doc77 Wrote:
(01-11-2024, 09:36 PM)Doc77 Wrote:
(01-11-2024, 09:23 PM)Tim Curtis Wrote: Pubblica uno screenshot della scheda Traccia in Informazioni audio. Verranno visualizzati i tag del file.
Caro Tim, perché se imposto "DSD over PCM" invece di "DSD Native" non sento più alcun suono dai miei altoparlanti?
Si prega di consultare l'allegato.
Molte grazie
Per il DAC Katana è disponibile un'opzione chip per attivare/disattivare il supporto DoP. L'impostazione predefinita è Attiva ma forse a un certo punto è stata disattivata? Le opzioni del chip possono essere modificate in Audio Config.
DoP è per dispositivi audio che utilizzano un chip DAC che supporta sia DoP che DSD nativo ma un'interfaccia che supporta solo PCM. Ad esempio, il DAC Allo Katana utilizza un chip DAC ESS9038 e un'interfaccia I2S. Il chip ESS supporta sia DSD nativo che DoP ma l'interfaccia I2S supporta solo PCM.
Lo stesso chip viene utilizzato nel DAC Allo Revolution, ma questo DAC utilizza l'interfaccia USB che supporta Native DSD, quindi il DAC accetterà sia DoP che Native DSD.
Sorry for the post in Italian, using Chrome's instant translator I didn't realize that I hadn't written in English!!
What changes if an audio track in DSD comes out directly in PCM without first going through the DoP? Do I lose quality?
Maybe for a few euros then it would have been better if I took the Khadas Tone 1 USB... I was undecided but the innomaker cost almost half the money
01-13-2024, 07:32 PM (This post was last modified: 01-13-2024, 07:44 PM by Nutul.)
(01-13-2024, 05:12 PM)Doc77 Wrote:
(01-13-2024, 12:13 PM)Tim Curtis Wrote:
(01-13-2024, 10:04 AM)Doc77 Wrote:
(01-11-2024, 09:36 PM)Doc77 Wrote:
(01-11-2024, 09:23 PM)Tim Curtis Wrote: Pubblica uno screenshot della scheda Traccia in Informazioni audio. Verranno visualizzati i tag del file.
Caro Tim, perché se imposto "DSD over PCM" invece di "DSD Native" non sento più alcun suono dai miei altoparlanti?
Si prega di consultare l'allegato.
Molte grazie
Per il DAC Katana è disponibile un'opzione chip per attivare/disattivare il supporto DoP. L'impostazione predefinita è Attiva ma forse a un certo punto è stata disattivata? Le opzioni del chip possono essere modificate in Audio Config.
DoP è per dispositivi audio che utilizzano un chip DAC che supporta sia DoP che DSD nativo ma un'interfaccia che supporta solo PCM. Ad esempio, il DAC Allo Katana utilizza un chip DAC ESS9038 e un'interfaccia I2S. Il chip ESS supporta sia DSD nativo che DoP ma l'interfaccia I2S supporta solo PCM.
Lo stesso chip viene utilizzato nel DAC Allo Revolution, ma questo DAC utilizza l'interfaccia USB che supporta Native DSD, quindi il DAC accetterà sia DoP che Native DSD.
Sorry for the post in Italian, using Chrome's instant translator I didn't realize that I hadn't written in English!!
What changes if an audio track in DSD comes out directly in PCM without first going through the DoP? Do I lose quality?
Maybe for a few euros then it would have been better if I took the Khadas Tone 1 USB... I was undecided but the innomaker cost almost half the money
Nothing. Or, at least, nothing that you could possibly hear. Unless, of course, you have Hans Beekhuyzen's ears.
If you are interested there are some academic papers that elaborate on why DSD not only has no benefit in regard of sound quality, but can also be source of artifacts. Handle with care - belief-dismounter lecture.
Seriously, no, nothing to worry about sound quality.
(01-13-2024, 10:04 AM)Doc77 Wrote: Caro Tim, perché se imposto "DSD over PCM" invece di "DSD Native" non sento più alcun suono dai miei altoparlanti?
Si prega di consultare l'allegato.
Molte grazie
Per il DAC Katana è disponibile un'opzione chip per attivare/disattivare il supporto DoP. L'impostazione predefinita è Attiva ma forse a un certo punto è stata disattivata? Le opzioni del chip possono essere modificate in Audio Config.
DoP è per dispositivi audio che utilizzano un chip DAC che supporta sia DoP che DSD nativo ma un'interfaccia che supporta solo PCM. Ad esempio, il DAC Allo Katana utilizza un chip DAC ESS9038 e un'interfaccia I2S. Il chip ESS supporta sia DSD nativo che DoP ma l'interfaccia I2S supporta solo PCM.
Lo stesso chip viene utilizzato nel DAC Allo Revolution, ma questo DAC utilizza l'interfaccia USB che supporta Native DSD, quindi il DAC accetterà sia DoP che Native DSD.
Sorry for the post in Italian, using Chrome's instant translator I didn't realize that I hadn't written in English!!
What changes if an audio track in DSD comes out directly in PCM without first going through the DoP? Do I lose quality?
Maybe for a few euros then it would have been better if I took the Khadas Tone 1 USB... I was undecided but the innomaker cost almost half the money
Nothing. Or, at least, nothing that you could possibly hear. Unless, of course, you have Hans Beekhuyzen's ears.
If you are interested there are some academic papers that elaborate on why DSD not only has no benefit in regard of sound quality, but can also be source of artifacts. Handle with care - belief-dismounter lecture.
Seriously, no, nothing to worry about sound quality.
Okay! Thank you very much for your reply and for attaching this interesting document!
Objectively, from what I see on my pi4, if I have a DSD source, I always get 32 bit PCM audio at the output, even if the DSD was first encoded in DoP..
Finally, to answer @Tim, the DoP option is correctly enabled in the chip options.
DoP is where DSD format is packed on-the-fly into PCM frames that contain a special "DoP flag" that tells the DAC to unpack the frames and send the bits to the DSD processing section on the chip.
The DoP PCM formats are:
DSD64 -> 24 bit / 176.4 kHz
DSD128 -> 24 bit / 352.8 kHz
If you see 32 bit instead of 24 bit its because the DAC only accepts 32 bit word length. In this case 24 bit is simply zero-padded to 32-bit. The original 24 bits of data are left untouched.
01-13-2024, 10:23 PM (This post was last modified: 01-13-2024, 10:38 PM by Doc77.)
(01-13-2024, 09:49 PM)Tim Curtis Wrote: DoP is where DSD format is packed on-the-fly into PCM frames that contain a special "DoP flag" that tells the DAC to unpack the frames and send the bits to the DSD processing section on the chip.
The DoP PCM formats are:
DSD64 -> 24 bit / 176.4 kHz
DSD128 -> 24 bit / 352.8 kHz
If you see 32 bit instead of 24 bit its because the DAC only accepts 32 bit word length. In this case 24 bit is simply zero-padded to 32-bit. The original 24 bits of data are left untouched.
Exactly as you see in the attached screenshots. The only difference, as we have already said, is that by selecting Dop, I have no sound (i2s only pcm..)
But from DSD 1bit I don't get PCM 176.4 khz, but PCM 352.8 Khz?!?! The .dsf file is the same DSD 1 bit 2.822 Mhz: this is a DSD64 or DSD128 ??
Is this normal?
Just an FYI to be careful when buying DAC's based on the ESS90xx chips. Only a handful of I2S DAC's for example Allo Katana and Audiophonics ES9038 are designed along with their firmware and Linux kernel I2S drivers to provide full access to ESS chip options, hyperstream hardware volume controller and DoP. Same goes for USB DAC's based on ESS90xx especially if they claim to support DSD but do not explicitly specify both Native and DoP.
As always, ask the manufacturer or on Forums like diyAudio that typically discuss such products in detail.
(01-13-2024, 11:50 PM)Doc77 Wrote: If my file is a DSD64, why my pcm audio output is 352.8 khz and not 176.4 khz ??
Those are the frequency slots for DoP. In your case it's not DoP, it's true PCM reconstructed from DSD, and probably is being done to the highest PCM supported frequency.
(01-13-2024, 09:49 PM)Tim Curtis Wrote: DoP is where DSD format is packed on-the-fly into PCM frames that contain a special "DoP flag" that tells the DAC to unpack the frames and send the bits to the DSD processing section on the chip.
The DoP PCM formats are:
DSD64 -> 24 bit / 176.4 kHz
DSD128 -> 24 bit / 352.8 kHz
If you see 32 bit instead of 24 bit its because the DAC only accepts 32 bit word length. In this case 24 bit is simply zero-padded to 32-bit. The original 24 bits of data are left untouched.
Exactly as you see in the attached screenshots. The only difference, as we have already said, is that by selecting Dop, I have no sound (i2s only pcm..)
But from DSD 1bit I don't get PCM 176.4 khz, but PCM 352.8 Khz?!?! The .dsf file is the same DSD 1 bit 2.822 Mhz: this is a DSD64 or DSD128 ??
Is this normal?
Here is the (i) help for MPD DSD support option. I've added more info below each of the options to help explain whats going on.
Native DSD: If the audio device reports that it supports Native DSD then MPD will send the unaltered DSD bitstream to the device otherwose MPD will perform DSD to PCM on-the-fly conversion.
For DSD to PCM on-the-fly conversion, the PCM rate thats sent is determined by MPD and ALSA, is a multiple of 88.2 kHz up to the max rate the audio device supports. For I2S DAC's the max rate is 384 kHz and thus DSD64 is sent at 352.8 kHz, DSD128 and above will be sent at 384 kHz. IIRC for USB DAC's that support higher PCM rates the on-the-fly rates for DSD128 and above will be higher multiples of 88.2 kHz.
DSD over PCM (DoP): There is no way to detect if an audio device supports DoP so only enable this if you are certain that the device support it otherwise the encapsulated DSD bitstream may cause loud or unpredictable distortion.
The DoP spec stipulates:
DSD64 has to be sent as 24 bit / 176.4 kHz
DSD128 has to be sent as 24 bit / 352.8 kHz
