The Importance of the Digital Cable

Digital cables can make a  noticeable difference ,the latest                           Wire-world Platinum 8 is a excellent example  excellent detail 
and a verygood balance ,not as cool as the older 7 series,
also is possible buying a dac on upper tier with A Streamer module built in is better in several ways such as the Bricasti -M3
Dac-Streamer  excellent detail and musicality ,Roon ready .Ethernet is noticeably lower noise,then spdif,band,or usb, and by having the streamer in the same chassis in a premium dac 1 less power cord,and cable 
and much better isolation ,all digital signals are totally isolated 
from noise and digital single is not unpacked and converted until 
it arrives to streamer, this too applies from server,or computer 
do to several Linear power supplies,filtering,and pre and post voltage regulation dual AD 1955 Multibit dacs ,and R2R and filters in upper models , and many other 
more complex duties,a true bargain IMO that’s why switched from just a very good dac , and the future of things to Come ,Bricasti has been in professional mastering studios for years directly because of their implementations in correct digital playback .Their upper M1,and Flagship M21 are noticeably better still.

OP. Not only can I not remember the cable brand. I don’t remember the two box CD brand… I never had a great memory and it is not getting better. Brands I spent a lot of time with back then were: Straight Wire, Cardas, Nirvana, Harmonix, DH Labs, and Audioquest. I never had a very positive experience with the last. I use Transparent now.

+1 @kijanki  for mentioning timing, the influence of reflections in the cable and
how distortion affects the shape of the square wave. It's rarely mentioned how important it is to retain the integrity of the square wave from source to destination (DAC).

Yes, electrical noise will be very important contributor affecting not only transmission (creating time jitter), but also polluting everything else. Reflection created jitter in cable plays separate role. Reflections will produce time jitter of the signal hence added noise on analog out.  Two cables that have exactly same shielding may sound quite different because of impedance mismatch (one is a better match to DAC's input impedance).

Hi Kijanki,

Thanks for that really superb answer. Very informative indeed. So you are reinforcing the notion that electrical noise i.e. EMI / RFI are the primary contributors to that very slight but audible change In sinewave i/ conversion clocked signal? So, aside from the clock itself, which as you indicate is never perfect, the cable transferring the digital signal is differentiated in performance primarily by ability to shield from EMI / RFI?

Hi MillerCarbon,

Thanks much for the input. I do believe powercords will be a positive upgrade for me, but I have yet to venture down that road though will in the near future. I am in the same boat as you regarding some of Synergistic Research’s products ( I have the Foundation speaker cables and set of four cable risers - which dramatically change the sound). As you’ve probably experimented with different types, can you state your preference for powercords and cables that are not priced into the stratosphere (I know some of your system is very expensive).

Yes, cable delivers digital information to D/A converter to produce analog (audio) signal. When this information is delivered in exactly same intervals then everything is always the same - perfect reproduction, but the problem is, that exact moment of D/A conversion can be affected by many factors and intervals become uneven (jittery). When this happens extra information is added to original signal. To understand this let’s imagine that you transfer constant 1kHz sinewave, but because of 60Hz noise moment of conversion (D/A clock) moves slightly back and forth in time 60 times a second. Now instead of pure 1kHz sinewave you will hear additional signals (sidebands) at 940Hz and 1060Hz at very small level. There will be many more, spaced by 60Hz, but because of smaller amplitude only first two (940Hz, 1060Hz) count. Amplitude of these sidebands will be proportional to amount of shifting in time (jitter).
These sidebands are extremely small, but still audible because they are not harmonically related to root (in this case 1kHz) signal. With many frequencies (music) there will be a lot of sidebands - practically added noise. This noise is proportional to signal level and without signal you cannot even hear it, but it is responsible for loss of transparency, loss of imaging, harshness etc.

So, now we know what happens, but why it happens? What can affect D/A conversion clock. To start with, this clock itself doesn’t have perfectly square edges and any noise in the system may add to edge (make it jagged) changing slightly moment of threshold crossing. What else? D/A clock has to be synchronized somehow with incoming S/Pdif signal, otherwise samples might get lost. It is done by taking average of S/Pdif signal word rate and using it to clock D/A converter. In spite of using average (no filter is perfect) timing variation in S/Pdif affect D/A clock. Where they come from? Electrical noise is obvious culprit. It adds to edges (making it jugged) changing moment of level recognition (threshold). Shielding, grounding, isolating etc. might help. It might be even worse for Toslink that being not sensitive to noise pickup is affected by system noise at both ends (Toslink transitions are slower).
Another culprit is reflection in the cable that adds to the edge (makes it jagged). This reflection happens when cable’s characteristic impedance is not matched to DAC input or Transport output. Beginning of the transition starts reflection from impedance boundary (usually cable’s end), that comes back and adds to rest of transition modifying its shape.

Characteristic impedance is very difficult to measure, so it is trial and error and expensive coax is not necessarily best match to impedances in your system. Shielding, of course is very important.

Hope it helps.

Thanks for the responses all. Calvin&Hobbes, Thanks for the great links and superbly detailed reply. 
So EMI / RFI comes to the fore again. Just as with streaming, this is a key culprit in sonic degradation.

Thanks GHDprentice, thats a great story on the transport to DAC. its exciting when one discovers how something considered less significant ends up making a profound difference. By the way, if you can remember what brand/kind of cable was it?

Of the two cables I mentioned, the Canare looks to be the better shielded of the two. The Veloce is beautifully constructed and ‘soft’ the way Chris does things (wonderfully), but the Canare is very well constructed too, with significant outer shielding and heavy duty connectors - although I prefer the Black Cat connectors and the general ‘feel’ of the cable. So If outer shielding has been addressed so well on the Canare, then it must be internal? I believe the metal / wire itself must influence the signal transfer integrity.

Hi Yuviarora, the Veloce I believe might use cotton as Chris utilizes Japanese cotton in his cables. You seemed to have delved pretty deeply here, trying different topology types.

Hello Melm, I thought the forum was open to discuss the subject we love. I have ‘googled’ but there is no substitute for talking with the audiophiles here with many years of practical experience. So are you saying that the digital stream/signal from computer to DAC is not a binary signal with packets etc., but rather a square wave, which is then converted to analogue by the DAC?

Jond, thanks, i will check out the Jorma digital cable.

thanks Roxy and Pauly for the response too

How can a power cord make any difference? After all it's only AC. How can 5 feet make any difference? After a thousand miles the last 5 feet is so critical? How can a speaker cable make any difference? As long as the wire is thick enough....  How can an interconnect make any difference? After all it is only a volt or two? How can I ask these questions? After all I'm not an engineer. Why does it matter? After all I'm not going to build anything. Why do I care? After all it doesn't help me choose components. Why don't I just buy whatever sounds the best?   

Good question.  

Probably the most unexpected and profound difference I have ever heard was between a CD transport and DAC about thirty years ago. While I had already given up trying to explain why different wires sounded different, I was absolutely positive a digital connection would not depend on the wire, as analog did. When I swapped anyway just to prove it to myself, my jaw dropped… it sounded as if someone had switched components to much high grade ones.


Any inclination left before this incident to “logic out” what I was going to hear was gone after this. I read sonic reviews and listen. Although in all honesty, I put off upgrading to a high quality component streamer (its just a stream of bits, right?) by this stubborn reluctance to think it should matter with digital. Added a good streamer… jaw dropped again.

You write: "After all, it is transporting a digital binary signal?"

Actually that's incorrect.  Like all wires, it is transporting an analog signal consisting of imperfect square waves.  Imperfect because it doesn't have unlimited bandwidth.  How imperfect?  That will depend on how the cable was manufactured.

Beyond that it's a complicated story.  There's loads of information about this on the 'net.  Start using Google on the subject.

I can't tell you why either but I've found the digital cable to make perhaps the most difference of all cable types. I consider myself very lucky to have stumbled upon a used Jorma Digital cable some years back it's truly fantastic.

I'm totally ignorant as to why they make a difference and am not going to pretend otherwise, but I do know they make a difference as I have heard it with my own ears.

And it's not restricted to Coax and Toslink. I have heard differences in USB cables. 

All Digital signals are still electrical in nature. The metal, construction gauge, shielding, or lack there of makes a difference in sound. Copper foil USB cables are detail monsters, and in my experience heads and shoulders better than anything I have tried so far.
I make all my cables, and have tried every combination possible...Pretty much.

I prefer cotton as the shielding, sounds the most natural to my ears. Foil>Solid>Litz>stranded. 
Stranded has the lowest resolution, and has noise problems. 

Reduction of EMI & RFI.

Some reading on the topic:

Bob Stuart, Meridian Audio "Of course digital bits-are-bits and with due care, each of the three interfaces (USB, Toslink, coaxial) can deliver the same data at approximately the same time. But the audio we hear is analog and real-world devices are subject to a variety of interferences including data-induced jitter, other process-induced jitter, (and) common- and differential-mode electromagnetic noise. In the ideal world, the data are clocked in by and buffered in the DAC (asynchronous mode) and then de-jittered before conversion. In my experience this can never be perfect, just made closer and closer to irrelevance."

Gordon Rankin (introduced the digital audio world to asynchronous USB transfer)when I transfer a file over USB to an external hard drive it doesn’t make transfer errors – the file at the destination is the same as the source – so why should sending digital audio over USB be any different? https://darko.audio/2016/05/gordon-rankin-on-why-usb-audio-quality-varies/

The fact that EMI and RFI can induce digital jitter may be an explanation why some cables (interconnect & power cables) can sound better than other on digital gear if they are able to better reject or even reduce EMI and RFI. Sharing an IEEE journal article on the topic.A simple model of EMI-induced timing jitter in digital circuits, its statistical distribution and its effect on circuit performance, IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY, VOL. 45, NO. 3, AUGUST 2003: https://eprints.whiterose.ac.uk/640/1/robinsonmp2.pdf

I don't know how they make such a difference, but I have had the same experience.