Issues when recording optical s/pdif output from windows and macOS laptops

[artburda]

I noticed that the Sony PCM-D100 records digital input via toslink from my asus n56vz as well as my macbook pro (late 2013) only in 16 bit but always with the correct sampling rate, just not in 24 bit when the source file is in 24 bit. I read on a RME forum that the issue is caused by the outputting devices not sending the right channel status data, so that the Sony interprets it as 16 bit. In the case of the RME user it was a Sony PCM-D50, but I think it‘s the same issue.
https://forum.rme-audio.de/viewtopic.php?id=6243

The fireface user wrote the following and the RME supporter agreed:
„The 24 bit output of FF400 has a constant value of 00 (for all the bytes 4-13 and 14-23), whereas my other sources put varying values in byte 4:
- computer sound card (24 bits): 08 Sony sees it as 24 bits
- newer DVD player (16 bits): 02 Sony sees it as 16 bits
- older CD player (16bits): 00 Sony sees it as 16 bits
So, here is my interpretation of the results (total guess, I'm no expert):
08 : 24 bits
(04 : 20 bits ?)
02 : 16 bits
The default value of 00 is being treated by Sony conservatively as 16 bits rather than 24.“

I tried installing all possible realtek and microsoft drivers with no success. Is there anything I can do to make the soundcard send the right channel status data?

 

[Pluto]

Is there anything I can do

Probably not; the channel status bits are probably a function of the system hardware and, therefore, difficult to change. Combine a possible problem in this area with the digital input of an old-ish recorder and you have the proverbial unstoppable force up against an immovable object. You will probably need to think in terms of an imaginative workaround. It would also help to ascertain, somehow, which of the pair is actually at fault. It could be either, or both

Maybe a USB → SPDIF converter would achieve the result you require if the status bits it outputs are more to the recorder's liking but, whatever you do, don't spend money without testing the kit first because I can tell you from bitter experience that interfacing old digital recorders, especially those that purport to have supported SCMS nonsense*, is a total pain in the ass!

* I do not know whether that applies here

 

[artburda]

Unfortunately, it does apply. I did some tests with CD‘s and digital files on a USB stick. The copy protection for example in my Pioneer BDP-160 is ridiculous. When connected to a coax to toslink converter, I can copy CDs, but not one single digital file from a USB stick, not even a self generated test tone or audio recording. However, I can make ISO copies of SACDs when connecting to my pc with a network cable I can also copy anything from my pc or mac, but it only works in 16 bit.

The only real use case I have, is to set the digital output in listening mode to the Motu virtual loopback, so that I can make a safety copy to the sony in parallel to the recording in my DAW. Unfortunately, it‘s only possible in 16 bit. Which means -96dB noise floor, which would be the same as making a line in recording with the Sony.