USB and DoP or i2s with sample rate conversion 176.4?

Hello, I am using an Audio Alchemy DMP-1 running as Roon endpoint connected via i2s. I must admit I hate seeing all the sample rate conversions in the signal path.

I’m doing my best to A/B both methods but any differences are either subtle, or I do NOT have a good ear for these things. Theoretically which approach should be better, who’s actually doing the sample rate conversion, is it the Roon software?

I searched the web but could not find clear answer on whether you can do DoP over i2s. Oddly when I go to the DMP-1 setup page, there is a DSD option of either NONE or DoP of both USB and i2s. But selecting DoP for i2s results in no sound, must set to NONE.

After the DDP-1 it’s XLR to a pair of Audio Alchemy Monoblock amps and on to a pair of Magico S3s. See screenshots.

What DAC are you suing?

Some DACs can do DoP over I2S. I have seen the PS Audio DirectStream do it–it uses an HDMI connector, though, not the same one as what is on the DMP-1, so I can’t test it with our DMP-1 here… :frowning:

As for USB vs I2S, I don’t think I’d hesitate to use either. With a dedicated device like the DMP-1 as the source, both should be extremely clean. Maybe Audio Alchemy has more thoughts on the matter.

Roon’s DSD->PCM conversion should be transparent to the listener, but it’s still an extra conversion. All things equal, I think I’d lean towards the USB connection, assuming there isn’t a way to make DoP over I2S work in their world.

Thank you for the reply Brian, I am using the Alchemy DDP-1 built in DAC. The i2s connector is the mini DIN type.
Both the DMP-1 and DDP-1 are powered using the Alchemy PS-5 power supply.

I will do more A/B testing by ear tonight.

I also tried dCs method for DSD-USB but could not get that working either.

dCS method is only for compability with certain early dCS products which encode DSD differently.