Toslink

The history behind that is that TOSLink transmitters would often have measurably high jitter. But if your streamer does not exhibit that or if your DAC's receiver mitigates jitter then that shouldn't be an issue for you. The other benefit of TOSLink versus S/PDIF or USB is that there is no electrical connection between the transmitter and receiver.

Sometimes Toslink may not handle sample rates higher than 96 kHz. If the connection is iffy at a sample rate of 176.4 or 192 kHz, usually what happens is that the output will sporadically mute because synchronization is being lost between the streamer and the DAC.

SPDIF usually handles up to 192 kHz PCM and DSD64 if using the DSD-over-PCM (DoP) protocol while USB can handle up to 384 kHz PCM / DSD128 (DoP) or even 768 kHz PCM / DSD256 (DoP). Some DACs offer native DSD playback over the USB interface, though the streamer must support the feature with that particular DAC.

So it really boils down to what type of sampling rates you want supported and whether high bitrate DSD is important to you.

I think Toslink is still most likely to be an inferior interconnect. It has two extra stages in conversion that are unnecessary. Also, for most companies it is an add on just in case… so stock electrical -> optical and back. It is not so much the transmission media but unnecessary conversions.

SP/DIF has been the oldest and used for decades… then USB… needing completely different receiving processing and optical. AES is a newer, made for high end audio which I thing is just balanced SP/DIF connection.

As far as connections, in general, AES… preferred, SP/DIF , then USB (depending on DAC) then optical.

If the DAC is optical only it is likely an inferior DAC.

I think it very much depends on the DAC. If this is an older DAC, then probably. Older DACs, before USB asynchronous was ubiquitous did not have the jitter and timing stability that they do in the last 10 years or so.

If you are getting an older DAC you’ll find that upsampling really will help the performance.

Kind of for this reason I normally try to steer users away from them. The Wyred4Sound Remedy is a very good solution if your streamer doesn't already do upsampling internally.

@ghdprentice 

AES/EBU was developed before SPDIF for professional use. SPDIF is a 'consumer-oriented' variant of AES.

@yage 

OK, thanks, but in the high end audio world SP/DIF has been the preferred connection for decades and AES is relatively newer.

I have half a dozen digital pieces connected in my audio system, none using toslink connections. Only toslink connections I use is in my TV/video system. Must be a reason...

I use toslink between my Brennan B2 and Denafrips Pontus 12th Anniversary DAC! If you go the toslink route get this cable!

http://www.lifatec.com/toslink2.html

- without prejudice to any of the limitations or warts associated with Toslink , @kingbr has highlighted above, a glass fibre Toslink cable is a clear step-up performing choice.

- if you are still committed or married to using Toslink cables , then think quality build and superior performance opticsl glass fibre options vs cheap build budget plastic choices. The optical glass fibre audio performance uptick is not subtle.

- So think WIREWORLD SuperNova 7 Toslink Optical Audio Cables as the popular best of breed choice (… I agree …) ; with DH LABS and LIFATEC as other quality build choices . I’ve used them all over time, in my “ B” 2.1 audio system, currently upgraded to the WIREWORLD for my TV audio output to the DAC.

note: it’s all HDMI for TV sources ( cable box, BluRay player, Apple TV) to the SONY TV panel, then WIREWORLD Toslink opticsl glass cable out for audio only to an ARCAM DAC, and quality build RCA interconnects from the DAC to to my 2-channel ARCAM integrated amp)

I would strongly recommend upgrading to either a SPDIF/ RCA, or BNC, or USB cable link options over any Toslink for a pure audio system whenever possible. ( I use a CARDAS CLEAR here in my “A” system)

FWIW

What dac would only have 1 option for connections ?  You didnot mention  that  to see it’s build quality .I would say look for something else . All quality dacs I have tried ,or heard had multiple inputs.

The DAC under consideration is the Wattson Madison.  It has a SPDIF input and a Toslink.  I would need the SPDIF for my CD transport.  The Wattson has a built in streamer but I found it sounded better when I ran my Bricasti M5 through its SPDIF. But again, I will need the SPDIF for my CDT.

Note: other DACs under consideration are the Synthesis Roma and the Less Loss Echo's end.  Both of these DACS have better connectivity options.  The Madison's advantages are size and its overall sound is pleasing.  Overall its a toss up.

@mdrone

- with any of your DAC choice options, it’s SPDIF over Toslink as the superior audio performance choice whenever possible …. Full stop.

- Defaulting automatically to the Toslink input in the Wattson Madison DAC would drive me to choose another DAC with better input options .

choose wisely.

The Wattson has an Ethernet input. Why not connect it directly to the network?

Looks like it also supports AirPlay, Tidal Connect and UPnP. You might not need your current streamer with this DAC.

When I switched out an optical cable to SPDIF, I noticed a blacker background, ie the spaces between notes.  Nice improvement.

As I stated, it sounds better with an external 

streamer

The best modern USB, in asynchronous mode, is currently the best consumer link. TOSLINK the worst. It was not always that way so a lot of valid old biases exist.  Can you hear it?  Only your ears can tell.  In a defective system with bad grounding, fiber does break that chain. 

High end fiber cables? Total snake oil IMHO but if you think they are great, then it is your enjoyment ( and money) that counts.  Sharp bends can cause issues so watch the radius. If long runs, like over 10 feet, then glass has less loss than plastic.  The fiber is not the limit, it is the SPDIF interface spec that is limited. We use fiber for 10G Ethernet.  Spend your money on the DAC, Amp, and Speakers. They make far bigger differences. 

I still prefer SPDIF and AES/EBU to USB in general.

A good glass TOSlink cable makes a big difference in my experience.  I've used WW Supernova cables on several occasions with satisfying results.  You just have to try things to see what you like better.

75-Ohm SPDF and USB traditionally considered to be better type of connection for audio, however comparison is kind a not fair due to lack of high quality Toslink cables on the market. In situations where you have to use interconnect longer then 5ft Toslink could be optimal and superior over other. If you have to use Tosliink, the Borosilicate Glass fiber cable is way better than plastic fiber. 

@mdrone

Apologies - I missed that in your reply.

It looks like the Toslink and SPDIF inputs on the Madison are equivalent in terms of technical capability. I don’t see a way for you to connect the Bricasti M5 to the Madison via Toslink though. The webpage only shows USB and AES / coax SPDIF digital outs.

If you’re averse to using Toslink still, there’s the option of putting in a SPDIF switcher so you can choose between the streamer and the CD player.

Otherwise, I suppose your DAC search continues.

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?

@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.