Ropieee and USB Passthru?

Sorry if this has been answered before or if its technically stupid…

I’m happy with RoPieee in general since I’ve been mainly using it via Roon. But there are occasions where I want to listen to Apple Music HiRes Lossless through my DAC (Oppo 205). Since Ropieee owns the USB connection to my DAC via the RP4, is there any software solution to share the single USB connection? (a passthru connection) I’d rather not have to unplug the RP4 every time I want to stream from the Mac mini sitting next to it.

How about HDMI from the Mac Mini to Oppo 205? But, I don’t know if that can do high def Apple Music.

I use Apple Music on iPad Mini 6 with a FiiO KA1 DAC and 3.5mm cable to Meridian Prime as pre-amp with RCA to Denon AVR-2805 Pure Direct and Pioneer HPM-60 speakers.

No I don’t think any device or software allows that. You could just use a usb hub and switch it but these can sometimes cause some issues with playback but a cheap option to try. Make sure it’s a powered one though.

Not knowing more about your system (what is your core? what is the topology of the connections? etc.).
It may be easiest to just ditch the RPi and use the mac mini as your endpoint feeding the Oppo (you mention it is right next to the Oppo or RPi)? So in essence the only real “software solution” that I can think of is a fully functional OS (Linux, Windows, Mac) that you can select the system output and player software you want.

The system in question is:

Roon Core: QNAP TVS-h1688x (QuTS Hero 5.1.3)
DAC: Oppo 205
RoPieee endpoint: Raspberry 4 (latest software)
USB connection between the RP4 and the Oppo 205
Mac mini 2014 (hacked to run macOS Sonoma 14.1.1)
Pre/Pro: Marantz 7703 serving a 7.1.4 home theater
Mac mini is connected to the 7703 via HDMI.

Macs of course have Airplay 2 but can’t do any better than 16/44.1 in most situations.

I hadn’t thought much about the HDMI input on the 205…I hadn’t tried to use it in years. I guess in theory that could be a source. If memory serves me correctly, there used to be problems with it and HDCP protected sources. But this isn’t one. Hmmmmm. Let me break out a cable, and see what happens. Of course there is a real problem that Apple Music might not recognize an HDMI output as something like a DAC (although there are a few other examples out there). But it can’t hurt to try.

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OK, I’ve discovered a few things…

First, I hooked up the Mac straight to the USB port on the Oppo 205 just to make sure that the default hires audio option works. And it did, although I did have to adjust the Audio MIDI program to indicate that the USB interface could take audio over 16/44.1. There isn’t a bit perfect option for this since Apple Music relies on CoreAudio to resample anything to what Audio Midi says, but this is still better than nothing.

But here is what surprised me. When I connected the Mac mini to the HDMI input of the Oppo 205, first, I got video and so that worked. The Mac also recognized the 205 as an audio source and I made sure that Audio Midi was set for 24/192 on the input. But when I played a track that I knew was hires audio, instead I got Dolby Atmos. I had set Apple Music to play every format to the output and the program correctly recognized that the 205 could understand Dolby Atmos. I turned Atmos off in Apple Music and it then sent a 24/96 stream as I expected.

Then I asked Roon to get into the mix and it asked it to recognize the HDMI output and the USB output, which it did correctly. HDMI input on the 205 cannot understand DSD so everything sent to that input will be converted to PCM. This isn’t so bad since I had intended for DSD stuff to be sent to the USB output anyway. But because of limitations with CoreAudio, DSD is limited to DoP which means that the 205 can handle DSD levels that DoP cannot send. That’s not horrible…all of my DSD recordings aren’t anymore than DSD128 anyway. Also, the HDMI input can handle the handful of multitrack ripped SACD and DVD-Audio recordings I have which is nice for a 5.1 presentation.

The one thing that is missing here is HQPlayer compatibility, which I typically use with RoPieee. I don’t normally play HQPlayer modified content in this room…I usually do that in the dedicated 2-channel room. But I might keep the Raspberry Pi around just for the two channel stuff and use of the USB interface, with the Mac handling the Apple Music/multichannel stuff. Haven’t decided yet.

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