ProtoDAC TDA1387 X8 project

[Tim Curtis]

That procedure worked nicely. Slight differences in some of the replies, but all went to completion and it's now running with the CDSP volume control and sounds good. I've had issues over the years getting stuff into the Moode filesystem from my Windows machine, so picking the file up with wget was nice.

Am I correct in assuming that the dithering done in this case makes the difference whenever 24 or 32 bit values are sent to the ProtoDAC? 

Appreciate your help very much.

Skip

Dithering is only applied to 16 bit samples because at that bit depth it can help reduce any noise in the lowest bit thats correlated to the audio signal and possibly audible.

For 24 or 32 bit samples dithering is unnecessary because any noise in the lowest bit would be at -144dB or lower and thats way lower than the noise floor of any audio device and way way way lower than the threshold of human hearing.

ETA: The TDA1387 chips used in the ProtoDAC are 16-bit DAC's and thus they simply truncate > 16 bit samples. An option is to set Camilla resampling or MPD/SoX resampling to specify 16-bit and let these components do the truncation/conversion instead. I've tested this on the few > 16 bit albums in my collection and can't hear any difference so I go for simplicity and just let the DAC chips do it.

Dithering
https://www.soundguys.com/what-is-dither-23700/