SPDIF out put on Mac Studio

Loren Ryter wrote:

confused in responses. did you find a solution that works and if so what? i am just setting up a mac studio and also want multichannel optical output. (or some kind of digital multichannel audio output at least.) would prefer to retain old receiver with optical input.

The OP didn't say anything about surround sound. I suspect he was looking for optical digital stereo output from his Mac to his stereo receiver.

It sounds like the OP's USB S/PDIF adapter had both coaxial and optical digital ports and a control for choosing which to use. The OP didn't realize that the control was there and needed to be set to the OPTICAL position for there to be audio output on the OPTICAL port.

If you're trying to get surround sound over S/PDIF, that's a completely different problem – and you should start your own thread.

I would not jump to the conclusion that it is impossible. More likely, you have a defective USB-to-S/PDIF sound card … either a particular sample that is defective, or one whose design is defective and does not work properly with the Mac. Or perhaps, a defective optical cable. Another card or cable might fix the problem.

In some other threads here, people mentioned HDMI splitters (which extract audio from a HDMI signal and make that audio available on S/PDIF outputs). I don't know how well those work, but thought I'd mention them.

How do I get digital audio out of my new … - Apple Community

Completely un-encumbered by knowing anything about the actual technical issues involved, I do know this:

When Audio, USB, Inputs, outputs appear in the same query, the answer often can be influenced by 'Audio MIDI Setup' in the Utilities folder. Try it, you have nothing to lose.

Your mention of 'Audio MIDI Setup' brought something to mind:

Maybe the OP needs to check the sampling rate in Audio MIDI Setup and make sure that the sampling rate and bit depth are set to something that is compatible with the receiver.

S/PDIF originally appeared in the context of home stereo equipment such as CD players (stereo, 44.1 KHz, 16-bit) and DAT recorders (stereo, 48 KHz, 16-bit samples). There are reports of some implementations going as high as 192 KHz / 24-bit, but it sounds like the original specification was for 48 KHz maximum – with anything above that, one might be risking interoperability problems.

https://forums.stevehoffman.tv/threads/24-192-over-spdif-already-possible.280538/

I don't know what to say.

My USB sound card works for me, even though it just has an analog output (in use), an analog input (not in use), and a switch to choose between them.

I don't have any reason to think that a USB sound card could not generate S/PDIF output. I did see that S/PDIF is one-way: there is no communication back from the receiver, to the audio source, to keep things in sync. So jitter is a possibility, though one would hope that an external sound card would pump out fresh samples on the S/PDIF side at a constant rate even if sound data did not always arrive on the USB side at a perfectly steady rate.

confused in responses. did you find a solution that works and if so what? i am just setting up a mac studio and also want multichannel optical output. (or some kind of digital multichannel audio output at least.) would prefer to retain old receiver with optical input.

Probably not it … but you might want to double-check that the cable from the S/PDIF output on the USB-C sound card is plugged into a S/PDIF input on the receiver.

I have powered speakers, connected to a USB sound card, connected to a downstream USB port on a USB-C monitor. They work fine. (No S/PDIF involved anywhere, though.)

Glad to hear that it's working.