Hi

[marcinmarcin]

Hello,

New here, but have a few tries with moode previously (also with volumio, ropiee, dietpi) 

Now using 830 64bit (installed with pi imager) + allo usbridge signature (with high quality LPS) + upnp renderer + mconnect - this combination seems best for my ears...

In moode direct hw, disabled software volume (null), 16mb cache, upnp renderer enabled.

[Tim Curtis]

I'm curious why you chose 'Null' instead of "Fixed (0dB) for Volume type.

[marcinmarcin]

Null because don't want to have software volume/additional mixer enabled.

Does it make a difference from technical point of view? Is sth disabled in chain when null is chosen?

Im not sure if there is a difference in SQ, but remember from my tests that null at least sounds as good as Fixed (0dB), if not better..

[Tim Curtis]

Null because don't want to have software volume/additional mixer enabled.

Does it make a difference from technical point of view? Is sth disabled in chain when null is chosen?

Im not sure if there is a difference in SQ, but remember from my tests that null at least sounds as good as Fixed (0dB), if not better..

If you are using a downstream volume control for example on a preamp or integrated amp then set moOde Volume type to "Fixed (0dB)". This bypasses MPD software volume control and outputs PCM without any attenuation being applied i.e. "bit-perfect".

Volume type "Null" is only appropriate when an alternate method is used that captures MPD volume events and sets the actual volume. By definition, Null would default to outputting 0dB PCM since the assumption is that some other volume routine would be doing attenuation.

For example if you are using a CamillaDSP configuration that contains a Volume filter, moOde will automatically reconfigure MPD internally to use Volume type = Null and then start the MPD2CDSPVolume proxy which captures MPD volume level changes and sends them to the CamillaDSP 64bit volume controller for output to the audio device.

This is what enables the moOde volume knob to use the nice CamillaDSP 64bit volume controller :-)

[marcinmarcin]

Generally on Volumio realised that volume on Camilla (Fusion) works with better quality. Is it because of 64bits?

I set -8dB in my dac/interface digital volume controller because of digital harshness/distortion, so I should use Fixed to avoid changes in stream.

When I had Chord Qutest, there were available hardware volume, but dac doesnt have any volume regulation. Does it mean some internal headroom? Qutest on hardware volume had no distortion, on 0dB fixed it was noticeable.

[marcinmarcin]

I will also ask if it's possible to change in config value S32_LE for dac Formats?

I play only 16/44,1bit, but usbridge send 32bit to dac (my dac/interface is 2x stereo in real, so traffic is 2x)

[Tim Curtis]

I have no idea what other audio players do. Maybe they use the low quality ALSA "softvol" controller. If CamillaDSP volume wee being used you just could open up the CamillDSP Pipeline editor and see the level meters in action. Best to ask these other projects directly.

Many USB audio devices only accept 32 bit samples and so thats what MPD/ALSA will send by zero-padding the samples. This still maintains "bit-perfectness" because none of the original bits are altered.

[marcinmarcin]

To sum up - enabling Camilla in moOde makes volume goes to null, and use Camilla 64bit volume instead
but when null on 0 without Camilla or 0dB set, is there any difference in chain?
I set to fixed (0dB) as you advised (thought previously that null means disabling digital volume at all).

[Tim Curtis]

There is no difference between Null and Fixed (0dB). PCM samples are output by MPD without volume processing.