I have an idea of what’s going on… and both apps can still be bitperfect.
Our audio stack is custom for Mac with no portable code – it is built using the Mac OS APIs, just like A+, including Darin’s paper explaining Integer Mode. As for RAAT vs DNLA, there is no debate on sound quality between the two. RAAT and DLNA are equals when it comes to SQ. Here is our problem with it:
https://community.roonlabs.com/t/whats-wrong-with-upnp/2101/3
@dabassgoesboomboom – I’d love for you to repeat your test but with this:
- run A+ and play
- run Roon while A+ is playing and just use the UI, but do not play.
Do you still hear the difference or does A+ sound the same now? Can you have someone else do the actions while you listen?
I’m wondering if your DAC + computer are not shielding RFI properly and your GPU is being driven harder by Roon, and RFI is leaking into your D->A process inside the DAC.
When Roon speaks to Core Audio in exclusive/integer mode, the apps can not be doing anything different here (assuming you are playing the same content w/ no changes like DSP. There must be something environmental, and the biggest thing I can think of is that Roon has a very heavyweight UI compared to A+.
Normally I would argue your device should be protecting you against this, but every device handles RFI differently. This is why we suggest you take the “Core” and “Remote” out of the listening device and use a network device to render audio. Even a USB bridge can isolate RFI generated from a GPU. On my Macbook Pro from a few years ago, I can visibly hear on disconnected speakers the scrolling of Chrome. Unreal.