Optical audio keeps briefly cutting out

Situation: Digital audio cutting out for about a quarter second at several seconds to several minutes intervals. There's no problem with an analog connection from the 3.5mm stereo speaker out port to the Sony receiver

Setup: ASUS ROG Strix Z590-E motherboard toslink cable from onboard S/PDIF out to Schiit Modi 3E DAC > DAC RCA out pair to Sony STRDH190 stereo receiver #1 RCA input pair > receiver speaker posts via banana plugs and 14-gauge speaker wire to Emotiva Airmotiv B1+ desktop speaker pair. CPU is i711700. RAM is 16GB of DDR4-3200. OS is Windows 10 Pro 22H2 (build 19045.4123). Audio driver is Realtek USB 6.3.9600.2342 dated 9-15-2022 downloaded from ASUS (latest audio driver for this motherboard).

History: This same setup, except with an ASUS Prime Z390-A motherboard, i79700 CPU and 16 GB of DDR4-2666, has been used for more than a year with no problems. The current motherboard, CPU and RAM were used in a similar S/PDIF setup that exhibited no problems except for USB wake delay that Sound Keeper solved. For some reason, shifting the inside hardware to another case didn't show any need for Sound Keeper.

What I've done: Changed every applicable driver setting combination, tried 2 different toslink cables from the PC to the DAC, tried different inputs on the receiver including the pair that work perfectly with analog inputs and tried a different RCA cable pair from the DAC to the receiver. Uninstalled the Realtek driver, installed the one on the ASUS CD that came with the motherboard (and then updated with the latest ASUS-supplied driver), tried another DAC and tried numerous audio sources. I even tried Sound Keeper. And I'm probably forgetting some things. Nothing has made any difference.

Anything obvious I missed other than a repair install of Windows? That's ready if needed. Or any other ideas? This is driving me nuts! Thanks for your help.

Is it the beginning of sounds that are being "dropped/cut/truncated" or right in the middle of a sound already being played? Like mid song when playing an MP3 or only the beginning of a new audio source, like the beginning of Windows beeps and sounds, or the first bit of a youtube video?

A lot of digital (SPDIF or Coax) audio devices will cut the very first fraction of a second of beginning audio output to avoid a "pop" sound when the audio stream is turned on. It could be your mainboard or your DAC doing it.

If it's mid-sound, I have no clue on that. I had that problem when using USB audio (DACs, Audio Interfaces), but it just "sorted itself" after I moved on past Windows 1809 builds.

SoundKeeper is a little tool that "plays silence" non stop, preventing the digital stream from ever stopping, and therefore restarting triggering the "cut" at the beginning of each new sound. It's good to test for that if nothing else. It is tiny and portable, no install or anything intrusive.

Thanks, Quexos. Unfortunately, it's a matter of constant cutouts. I already fought the battle of a delay at the beginning that was happily solved by SoundKeeper. I'm thinking now this problem may be caused by the DAC and have contacted the maker. Somebody who experienced the same problem I'm having reports that a F/W update solved it. I had tried my second DAC with the same result, but both I have are the same brand/model.

Everything is pointing more toward DAC disagreement with Realtek USB audio. Both DACs work perfectly with all optical outputs I've tried them on except ASUS ROG Strix Z690-E and Z590-E motherboards. Both of those have USB audio. Two older motherboards (ASUS Prime Z390-A) with non-USB Realtek HD audio have no problems. The 2 motherboards with USB audio both output to toslink ports in stereo receivers with no problems.

While this problem isn't gone, I'm sure enough of what the cause is that I'm marking it as solved.