Just curious which interface you're using with JRiver? I'm curious if it gives you any issues when using live in and ASIO drivers. I am using a RME which is a great product but when using live it can be problematic. I have read Motu units are great and Lynx Hilo are good as well. Looking to upgrade to different unit and I'm very curious what people find to sound great and most importantly play well with JRiver.
I use an old ECHO Audiofire 12 Firewire card. There are some inexplicable issues with ASIO, such as MC 64-bit not outputting any sound to it. Other 64-bit ASIO apps work. MC 32-bit works, so that's what I use. ECHO is unsupported at this point under Windows 10. When setup for surround sound, it presents two interfaces to Windows - one for channels 1-8 and a second one for channels 9-12 .
But there is no driver selection of available speakers. So unless you have a full 7.1 system, some of the channels are not output at all. For example, Youtube videos in mono play on the center channel which I don't have on my 4.1 setup in my home office. And thus they are completely silent. This affects many other apps, too. Fortunately, JRiver allows mixing and re-routing of channels using the WDM driver, and that "fixes" the ECHO bug for Directsound app. Sort of, since the added driver latency puts the video & audio out of sync. Enough that I have it disabled by default.
I have outputs 1-8 of the Audiofire 12 going to the 7.1 input of an old Yamaha RX-V2500 receiver.
The Audiofire 12 can function standalone as a mixer when PC is off, so that's a very good reason to keep it. The DACs and ADCs are both excellent.
You can also combine multiple Audiofires . I have Audiofire 8 as well. This makes it a cool 20 in/ 20 out interface under ASIO. The combined device requires the PC to be on, unfortunately. The two interfaces won't talk two each other directly over Firewire without the PC - no standalone hardware mixing between the two.
I got the pair of cards used for about $600. Not sure what I'll replace them with when they die, or if Windows 11 breaks them completely.
I have tried various brand new MOTU and Focusrite before I settled on the ECHO, and ran into various other bugs and limitations with them, so they went back. I'll live with the bugs I know for now.
Sorry I can't give you a recommendation on what to buy, but I could tell you what to avoid. Basically the ECHO are excellent hardware with buggy software, as is so often the case.