I’m a new user and don’t understand one thing. When I have chosen for Native DSD streaming method a DSD over PCM1.0 I got DSD Native at my XMOS processor. But when I choose None, convert to PCM, then I really got PCM protocol that caries DSD (DoP). It is confusing, can you confirm what I’ve said?
And I have a lot of noise (DoP) if I choose for Maximum Sample rate a No-Limit at a section For Bridge devices Connected to DAC. I see that the player upsample the music and then there is a noise. When I lower that freq. noise disappears.
Since the DSD format consists in a very high-frequency binary digits encoding, 0 or 1, its sample values can’t be multiplied or divided, unless converted down to PCM and then back to DSD. So native DSD doesn’t allow digital processing such as volume control or EQ.
Now go to settings and turn on Software Volume Control (bottom of the config menu), then try to play some music with None: Convert to PCM and play DSD file. Now try to increase and decrease volume, the player will do it.
Change settings to DSD over PCM and try again to inc/dec volume level, player will not do it because DSD native must stay bit-perfect (without any other changes like changing the volume). You can try it on some other player where you can inc/dec volume level while playing DSD Native and you will get a Noise, just noise.
I watched the bitstream of the communication (after the XMOS processor) on the oscilloscope and it looks like DSD Native.
Most of the postprocessing is done in PCM and converted back to DSD. There are few solutions for processing in native DSD, like Sonoma workstations.
DoP is native DSD stream packaged in PCM words for transport purposes. It‘s a native, bit-perfect DSD. Software volume control doesn’t work in this scenario as it would mess up the transport by messing with the bits and since you’re not operating on real PCM signal you would get garbled output.
If you convert it to PCM, you’re playing PCM. In this scenario you can use software volume control.
Do you mean that DoP is just to transport bits as PCM to XMOS (for example) and then XMOS converts it as Native DSD and forwards it to the DAC?
I would say that DoP protocol is when the processor transfers DSD native as PCM to the DAC. Between USB (Audirvana) and XMOS is USB protocol, not DoP. Am I right?
And between XMOS and DAC is a PCM protocol that carries a DSD bits.
Why would they write about DoP if it is already postprocessed by some processor? See the picture.
Yes, where the DSD stream extraction takes place I’m not sure. Don’t know if the XMOS has this capability or it just implements the USB interface. If it’s not at the XMOS chip than there is a chip behind it that removes the tagging header end extracts the DSD stream. For sure, the DAC chip or the processor that does the D/A conversion is presented with the pure DSD stream.
