ProtoDAC TDA1387 X8 project

[varunach]

It's might be due to the difference in the volume curves used by MPD  vs CamillaDSP.

I suppose a test would be to set moode volume at 100 (0dB) using both configurations and then see if the actual volume level heard is the same. Obviously set your Amp volume way down before doing this !!

Got it, thanks Tim. I tested this as you suggested and the actual volume in CamillaDSP is lower. I've also found that for whatever reason the audio clarity is better using ALSA polarity conversion so I'm sticking to it (might be my headphone + amp combo)

[Tim Curtis]

Interesting given there is no negative gain in the Pipeline.
Maybe a good question for the CamillaDSP thread in diyAudio.

[varunach]

Interesting given there is no negative gain in the Pipeline.
Maybe a good question for the CamillaDSP thread in diyAudio.

Yeah. FWIW there was a default 'negative 3db' gain applied in the 'Mixer' tab in the Camilla pipeline editor which i reset to '0'db. Still it sounds lower compared to MPD. @Tim Curtis btw I dont see the 'V2-ProtoDAC' option in the Signal Processing drop down setting. I've update Moode and CamillaDSP shows as version 2.0.1. Did we remove that configuration?

[DRONE7]

@varunach

Update the sample configs for V2.
https://www.moodeaudio.org/forum/showthr...0#pid52760

I concur re the volume discrepancy and preference for alsa setting vs CamillaDSP

[Skip Pack]

Are you turning CDSP off entirely, or somehow retaining the dithering in CDSP. In order to do that I think you would need to flip the input connectors at the speakers?

Thanks, Skip

[varunach]

Are you turning CDSP off entirely, or somehow retaining the dithering in CDSP. In order to do that I think you would need to flip the input connectors at the speakers?

Thanks,  Skip

Not sure I understand your question. The polarity inversion can be accomplished via Camilla DSP or via ALSA setting as stated in the guide. As for dithering, while using Camilla DSP you can set it, but in ALSA you can't. Although I didnt see any impact of not setting it. I think the ProtoDAC can handle 24bit to 16bit reduction just fine (if the software doesnt)

[varunach]

@varunach

Update the sample configs for V2.
https://www.moodeaudio.org/forum/showthr...0#pid52760

I concur re the volume discrepancy and preference for alsa setting vs CamillaDSP

Ah got it. Thanks for pointing this out to me.

[Skip Pack]

I edited the V2-ProtoDAC.yml file to turn off the polarity inversion leaving the dithering. That loaded fine, but I immediately noticed that the Alsa polarity inversion was not available until I turn of CDSP completely, leaving switching speaker leads the only possibility with CDSP dither. I'll test and report.

[DRONE7]

@Skip Pack
That's correct re alsa inversion and noted on the settings page ,
"DSP options
Note that the Equalizers, Crossfeed, and Polarity inversion are mutually exclusive. Enabling one will disable the SET and Toggle buttons on the others. "
So speaker lead inversion needed.

Dithering, currently experimenting with Pi>AKM-4137 (has Dithering enable option) >ProtoDac.

[Skip Pack]

The volume increase from turning CDSP off and ALSA polarity inversion on was much greater than I expected. More tests to come.