Toslink

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?

@mdrone wrote:

I am looking at a DAC that would require me to connect my streamer via toslink. I have read in the past that Toslink is inferior to SPDIF and USB connections.

Is that still true?

Does it depend on the the Toslink cable used?

With optical I’d say it mostly comes down to the specific input implementation of your DAC, and the context of use. I’m running optical from my music server/HTPC to the excellent ditto input of my DAC with a full 24-bit/192kHz PCM signal, and it comes in handy electrically isolating and preventing the noisy PC environment from entering my DAC - not an issue for you though. Or else I’ve had good results with AES/EBU and BNC connections in particular, in addition to USB via a SOtM streamer and external PSU, high-end sound cards (AES/EBU), the Audiophilleo 2 + battery PSU (BNC) and others with different, prior DAC solutions.

Having read quite a lot on the generally negative assessments (not least theoretically) on optical I/O, I was perhaps surprised to learn of its prowess in my setup - findings that mayn’t be replicated by others in their particular setup contexts, one might add. I was however happy to make my very own discoveries here, and it points to avoiding generalizations and instead making an effort towards forming your very own opinion based on actual experience, as well as trying to see the forest for the trees; what small increments in sonic advance are worth chasing, not least at what cost, and what is best left alone for a more pragmatic choice in the bigger scheme of things. Only you can decide, but I least have the courage to stand by whatever you deem important - irrespective of the opinions of others and any general consensus (formed on whatever basis).

Toslink can be good from a computer (like and old Mac) as it knocks out the computer noise with a physical electrical break . Modern streamers seem pretty quiet to me. All other things being equal they are bandwidth limited.