Toslink

No worries Yage.

You are correct vis a vis the M5.  If I went with the Wattson I would also need to buy another streamer ( with a Toslink output).

thanks for diligence’

No problem.

Here’s a switcher I found on B&H ($119). Looks like it’s from a company in Oregon that specializes in making gear for the broadcast market.

https://www.bhphotovideo.com/c/product/1351618-REG/inday_da4x_r_spdif_4x1_digital_audio.html/overview

Just something to consider.

Slow Toslink transitions convert system electrical noise (on both ends) to jitter (but Toslink is immune to ambient electrical noise and doesn’t create ground loops).

Fast coax transition produce reflections on characteristic impedance boundaries, that convert to jitter (deform original edge).

I use Toslink with Benchmark DAC3 (good jitter suppression).

There are some many variables - you have to try both in your system and in your room. Same goes for coax cables - the most expensive one, recommended by others can have poor impedance matching in your system, while the cheap one can be perfect. Pay attention to overall sound clarity since jitter converts to added noise.

USB should be the best, since it cannot directly induce jitter (being completely asynchronous), but can inject electrical noise to DAC affecting D/A conversion timing (indirect jitter).

I use a DH Labs Glass Master Toslink between my Technics SL-G700 SACD player and SU-G700M2 integrated as it simply sounds the best. It's the only cable that plays all of my CDs, beautifully. The Lifatec and Unique Products (Amazon) Toslink cables (and a few other generics) had drop outs on a few of my CDs, leading me think there was something wrong with the CDs. Also, two different lengths (3' and 6') of Unique gave completely different presentations, the longer being more robust and fuller sounding.

The same thing happened when I tried out a Coax made by a recording engineer I know, a Zu Audio Mission, a Audio Envy and a couple other generics. The same CDs simply wouldn't  play properly. That, and the RCA outs bested all of them.

The sound quality of the DH Labs is simply head and shoulders above the others. No contest. Not even close. I don't see why Toslink gets such a bad rap.

All the best,
Nonoise

I am limited by my smart tv to only output Toslink.

To my DAC. TV sound suffers.

There was a Digital conversion box suggested. But inputting Toslink and outputting coax will still limit quality to Toslink. Is that not correct?