@schmidtmike76 I have also been interested (academically at this point) in how the BDP-1, BDP-1 USB, BDP-pi, BDP-2, and BDP-3 would compare sonically in Roon Ready mode with everything disabled. Some devices have wifi capability, but shouldn't be used for the comparison. For this test, all devices should be connected via ethernet. Additionally, no USB devices should be connected to the device. The internal devices should also be removed. Same digital cables/connector of same length should be used. Three of the devices have AES, while the BDP-1 USB has USB only and the pi only has coax. That's another thing to consider.
If one wanted to compare MPD against Roon for SQ, the only fair way would be to have them both working over wired ethernet (NAS required for MPD). No usage of USB devices for MPD. Everything should be disabled and nothing plugged into the BDP's USB port.
Both MPD and Roon are bit perfect as long as you don't engage in any DSP. If there are any differences sonically between these two mode, they can arise from 2 possible ways. USB vs ethernet connections. If you are using USB devices such as flash drives or portable hard drives for MPD, it is possible they can be adding noise and modulating the performance of the sound card portion of the BDP. Chris Rice has alluded to this in the past, as has the developer of Auralic products. For example, Chris has previously mentioned the "billions of transistors" in SSDs injecting noise. Even James in the past has said that he finds slight differences in SQ between portable spinning hard drives vs. small thumb drives.
This is why I think eliminating USB devices altogether is the best option and also serves as a good control. When both MPD and Roon runs from ethernet, the data is coming from the same path and no additional devices could be influencing the SQ. If there is any difference in SQ in this minimal hardware configuration, the only logical argument would be that the differences in CPU processing has an electrical impact on the performance of the digital output of the BDP. As opposed to the USB vs. ethernet differences which are external, this difference in Roon vs. MPD would arise from internal mechanisms.
Hope that makes sense.
(I know Bryston's always been reserved in their opinions concerning SQ, but it would be lovely to hear from anyone at Bryston based on either objective data or simply their subjective impressions as to how to get the best SQ out of the BDP. If they think all these mode offer identical SQ, I'd be glad in hearing that as well. ANYTHING besides "whichever one sounds the best to you" lol. There's only so much a customer can do on their own end when it comes to testing. C'mon Bryston, I'll take anything