Are all toslink outputs made the same?

Hello everyone, I built a system around my desktop pc, I’m currently using toshlink with an RME ADI DAC 2 since usb brings a bit of noise, ive used the optical out from the motherboard and the soundcard, didn’t notice a difference between both optical outs, is the optical out from a motherboard good enough? Or would a usb to optical offer better sound quality?

I’ve tested if its bit perfect and it is. On another topic, I’ve seen so many people swear by expensive optical cables like QED Reference quartz and Wireworld Supernova, to me logically doesn’t make a lot of sense to be better as long as a cheap cable is bit perfect, but maybe theres a factor I’m not taking into account, anyone that has tried more expensive optical cables?

Is this something you have observed or measured? I’m asking because you are saying you didn’t notice any difference between USB and optical, if I’m getting this correctly.

I agree, it makes zero sense. Bits being the same, the DAC should be capable of eliminating jitter on both USB and optical.

How did you test that optical is bit-perfect? I’m not challenging this, I’m just curious.

Hi Marian, I meant both optical outs, usb noise is quite noticeble if I increase the volume ( played silent track to check noise ).

The RME adi dac has a feature that tests this, you have to play a few files supplied from rme themselves, the dac then lets you know if everything is bit perfect. Tried both optical and usb and all passed.

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Thanks for the clarifications. That’s a cool feature, I didn’t know about it. Regarding USB noise, what volume control did you use? Since USB is bit perfect, if there is noise, it would suggest the DAC is not isolating the USB input enough - which would be a shame at this price.

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To be fair, I can only notice the noise ( again only using silent track, not music ) when the volume knob is at a level that I would never listen to, and I would assume theres a lot of interference going on in a desktop especially if its mining bitcoin ahah

Fair point about interference, although, if it’s not large enough to flip bits, it should be filtered out by the DAC. Did you try this with optical also, i.e. playing silence? Also, you haven’t mentioned what volume control you’re using: OS, DAC or external preamp?

flip bits? its not digital noise that I’m talking about. It’s probably a ground loop or something, again I can’t really hear the noise at normal volumes, so it’s not an issue.

Well, there’s no digital noise, just analog noise that might flip bits… But anyway, if it’s not an issue, I’d go for USB, since it offers better integration.

Back when TOSLINK was very popular there was long debate between glass and plastic fiber cables. For the distance you’re connecting it should not mater. For longer distances (and in some cases if the TX is from a laser vs. a diode) it matters. The only way to know is to buy + listen. But, honestly, I would invest in a dedicated streamer and move towards USB. Especially if you want to use DSD with that DAC.

The primary drawback to toslink is it generally has higher jitter than other connection methods. Benefit is it’s completely electrically isolated and coming from a PC that’s a really good thing to have. Other drawback, it’s bandwidth limited so, depending on source, you may not get past 24/96khz rates.

It really depends on the source, but the reason I like USB better is that it can use an “asynchronous” model (which in fact uses isochronous USB transfer), in the sense that the DAC does not need to alter its internal clock’s frequency, but instead control the USB’s transfer rate. That is a more straightforward implementation. With optical (and S/PDIF in general), the DAC can’t control the transfer rate, so it needs to slightly vary its internal clock’s frequency continuously to take up deltas between its clock and the transport’s clock. If done properly and with generous internal buffering, the adjustments should be very small, so at the end of the day, they should sound the same.

Good god, no! After uber expensive Ethernet cables, the next biggest snake oil rip off.

Also, from all I’ve read, TOS is the most guilty with causing jitter.

USB shouldn’t be noisy. Are you feeding the DAC’s USB from your desktop? If so, that’s probably the culprit.

Try a simple streamer like an RPi running Ropieee placed between your desktop and your DAC, i.e. in a networked configuration.

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As stated by fellow members, Toslink forces the sending device’s clock upon the DAC, which could possibly introduce jitter related distortion becoming audible when reaching a certain elevated level.

That said, if you’re not hearing a difference between your mainboard or soundcard optical outputs, they’re probably both good enough in your setup, and you shouldn’t worry any further.

But, you could also use a true USB isolator to leverage all features of your DAC without getting noise introduced into your analog output.

I’m using an Intona USB 2.0 Hi-Speed Isolator, bought through their discounted eBay store, since I’ve had the same issue in my setup.

Before, I always had more or less audible artifacts, heard as random clicks, in the analog output no matter which Raspberry model and OS i tried, no matter if on Ethernet or WiFi.

I paid a bit more attention to the noise and it’s the typical electronic noise when you move your mouse etc. Does the intona help with that? I saw that ifi has the Defender and silencer, but don’t know which one is more appropriate for my problem.

I do have RPI with digione hat etc in my main system and bedroom system, I could try one here but wanted to avoid having more than 1 input, since sometimes I want to listen to music and other stuff at the same time.

I have ADI-2 DAC FS connected to my workstation with an Amazon Cable Matters 10 € USB C-> B cable. Drivers are rme ASIO Madiface drivers. OS is Win11. Mainboard is Asus ROG STRIX B550-I Gaming which has an AUDIO-USB-C compliant USB 2.0 audio interface. I have also tested a JCAT USB XE card against it. I could hear no difference. No Noise at all. ADI-2 DAC FS is not a roon tested device, I never accounted a problem with roon.

nevermind, already solved the noise, just disconnected the USB ground pin, rme dac doesn’t need ground from usb, now its as silent as optical

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Good to hear!
In my setup, even cutting both 5V and GND didn’t help.
And yes, the Intona does completely galvanically isolate data and power lines while transmitting at high speed USB, easily transferring 768kHz PCM/DSD512.