Volume difference when playing DSD vs FLAC

[Tim Curtis]

Your DAC has to support "hardware DSD volume" for example many of the ESS DAC chips provide this feature.

What model SMSL?

[TheOldPresbyope]

Your DAC has to support "hardware DSD volume" for example many of the ESS DAC chips provide this feature.

What model SMSL?

And even DACs containing eligible ESS chips may not offer hardware DSD volume control.

Examples that I own: 

- Khadas Tone1 board - this USB board contains the ESS ES9038Q2M DAC but offers only hardware PCM volume control through its XMOS controller

- Inno-maker HiFi DAC Pro board - this HAT also contains the ESS ES9038Q2M DAC and even uses the allo-katana-dac-audio I2S driver but offers no hardware volume control

Both boards sound great to me but I'd be disappointed if I had an extensive collection of DSD tracks and the belief that my ears were golden (I don't and they aren't).

Regards,
Kent

[Nutul]

If you send the DSD stream natively to the DAC there is no way you can control its volume in moOde.

one of the following must be true in order to have volume control for DSD:

- DSD needs to be converted to PCM in order for volume handling to be possible in the digital domain.
- the DAC converts it internally (and offers you a volume knob...)
- there is volume control in the analog section of the DAC

Or, as you see, you control the volume in the preamp, in full analog domain.

[Tim Curtis]

If you send the DSD stream natively to the DAC there is no way you can control its volume in moOde.

one of the following must be true in order to have volume control for DSD:

- DSD needs to be converted to PCM in order for volume handling to be possible in the digital domain.
- the DAC converts it internally (and offers you a volume knob...)
- there is volume control in the analog section of the DAC

Or, as you see, you control the volume in the preamp, in full analog domain.

DAC's using ESS chips that include hardware volume control for DSD don't need to provide a physical volume knob, they expose an ALSA hardware mixer (via their device driver) to the application software which can then control volume via software commands.

There's an ESS 9038q2m datasheet somewhere online that shows volume control implemented in the OSF (Oversampling Filter) section which basically means that DSD and PCM data are converted to oversampled PCM and then volume control is applied before the data is sent to the ASRC and then to the DAC section for output.