Toslink vs. S/PDIF for 15' run to DAC (Add a USB -> S/PDIF Topping D10)

[openbaffle3278]

Interested in some opinions here. My Digital audio source is currently my old style tower MacPro, which lives to the side of my main speakers. Currently running a 20' optical cable out of the MacPro to a Cambridge DacMagic Plus, which is between my speakers and close to my amp. Using the balanced outputs of the Cambridge to drive my mains and the RCA outs to power separate sub amps.

Running a 15' USB cable seems impractical/prone to problems, but I wondered if adding a Topping D10 right by my computer and going USB -> S/PDIF and then running a 15' S/PDIF cable would be a better option than the optical route directly out of the Mac.

I use Swinsian to playback lossless files on my computer (all 44.1kHz/16-bit CD rips) and also stream from Spotify.

Eventually, I'd like to upgrade the computer and get something quieter, like a 27" retina iMac. At that point I will have to use the USB -> S/PDIF convertor.

Another (less interesting to me) option is to move the DAC by the computer and run 15' XLR cables and 15' RCA cables out of the DAC and into my stereo sub amps and main amp. But I think that introduced unnecessary complexity, possibility to pick up noise (at least in the RCAs) and adds a fair bit of cable cost.

So I guess questions are:
1. Would running a 15' USB cable directly to the Cambridge be worse than the optical out of the MacPro (Has this been investigated in terms of degradation of the audio stream/introduction of distortion artifacts)?
2. Would getting a Topping D10 to act as a USB -> S/PDIF convertor and then running a 15' S/PDIF cable be the better option?
3. Am I overthinking this and should just be happy with the optical out, and save the Topping D10 cost towards my DAC upgrade?

My plan in the near future is to likely upgrade the Cambridge DacMagic Plus to an RME ADI-2 DAC largely based on the fact that I am looking for something that has remote volume control and due to its exemplary measurements presented on this forum. But certainly the Topping DX7S (since it appears that you can use a remote with this, albeit not included), Benchmark DAC2 HGC and Aune S6 are in the running as alternatives. My two main DAC requirements are:

1. Balanced and unbalanced outs that run simultaneously and can be attenuated from the DAC (no pre required in the system).
2. Remote volume and source selection control.

ETA I found this: http://archimago.blogspot.ca/2013/04/measurements-usb-cables-for-dacs.html, which would seem to indicate no measurable signal degradation with up to a 17' USB cable.

 

[Blumlein 88]

The active USB extenders from monoprice and elsewhere work fine. I've used one at 50 feet. Works no problems even at 192 khz rates. They are very inexpensive. I use one to feed my video system music from a computer that is 33 feet also with no problems.

Look for USB active extension repeater cables.

 

[openbaffle3278]

Thanks. Had an extra 12' printer cable around and also a 4' USB 2.0 extension so now I am running that into the Cambridge. Working quite well. I did see a few of the active repeater cables on Amazon/Monoprice. I might pick one of those up as well, but this is working.

 

[Fitzcaraldo215]

The active USB extenders from monoprice and elsewhere work fine. I've used one at 50 feet. Works no problems even at 192 khz rates. They are very inexpensive. I use one to feed my video system music from a computer that is 33 feet also with no problems.

Look for USB active extension repeater cables.

I have a cheap USB extension cable of about 38 feet or so. I have not used it into my DAC, but I have used it with my USB powered calibration mike. No problems at all.

I also have a 10 meter Corning glass USB, but that is not recommended for use with USB powered peripherals. So, I have not tried that with the mike. But, it works fine with my DAC.

 

[openbaffle3278]

I can't hear the difference between the 20' optical cable and the 12' + 4' extension USB cable.

 

[Fitzcaraldo215]

I can't hear the difference between the 20' optical cable and the 12' + 4' extension USB cable.

Not surprising. As long as you don't do anything crazy, the differences between USB cable hookups, comparing even cheap, generic ones, may be tiny to nonexistent, unlike the mythology expounded by manufacturers and paranoid audiophiles.

However, it is possible that different DACs react differently depending on how well engineered they are. But, it is simple enough to try alternatives if in doubt. As Amir's and others' measurements show, add on devices - Jitterbugs, Regen's, etc. - seem to be another big con job, although true commercial, non-audiophile USB isolators may in rare circumstances be of benefit.

As I said elsewhere, momentarily swayed by the anti-USB propaganda, I tried a 10 meter Corning fiberoptic vs. an inexpensive 5 meter plain USB cable. Any subjective differences I thought I heard were insignificant and quite possibly illusory. I slightly preferred the plain 5 meter, though I could comfortably live with either.

And, it seems that with active USB cables, extending effective useable length beyond 5 meters is no problem and inexpensive. More heroic measures, like USB over Ethernet, are largely unnecessary, except for really very long runs, and they likely are further plays to audiophile paranoia.

And, I see no reason to believe that Spdif or Toslink offer any superiority to USB. In fact, they limit bandwidth, hence sampling rates and channel count, as well as lacking the superior jitter suppression of asynch USB.

 

[Shazb0t]

Not surprising. As long as you don't do anything crazy, the differences between USB cable hookups, comparing even cheap, generic ones, may be tiny to nonexistent, unlike the mythology expounded by manufacturers and paranoid audiophiles.

However, it is possible that different DACs react differently depending on how well engineered they are. But, it is simple enough to try alternatives if in doubt. As Amir's and others' measurements show, add on devices - Jitterbugs, Regen's, etc. - seem to be another big con job, although true commercial, non-audiophile USB isolators may in rare circumstances be of benefit.

As I said elsewhere, momentarily swayed by the anti-USB propaganda, I tried a 10 meter Corning fiberoptic vs. an inexpensive 5 meter plain USB cable. Any subjective differences I thought I heard were insignificant and quite possibly illusory. I slightly preferred the plain 5 meter, though I could comfortably live with either.

And, it seems that with active USB cables, extending effective useable length beyond 5 meters is no problem and inexpensive. More heroic measures, like USB over Ethernet, are largely unnecessary, except for really very long runs, and they likely are further plays to audiophile paranoia.

And, I see no reason to believe that Spdif or Toslink offer any superiority to USB. In fact, they limit bandwidth, hence sampling rates and channel count, as well as lacking the superior jitter suppression of asynch USB.

What do you make of the Schiit Eitr?

 

[Fitzcaraldo215]

What do you make of the Schiit Eitr?

I know nothing about it, other than that Schiit has amply and beyond question displayed totally incompetent engineering. I would not get within a hundred miles of anything they make.

 

[Blumlein 88]

I know nothing about it, other than that Schiit has amply and beyond question displayed totally incompetent engineering. I would not get within a hundred miles of anything they make.

I concur.

At this point unless you have solid measurements proving otherwise, you assume any Schiit product is incompetently engineered.

 

[rebbiputzmaker]

I concur.

At this point unless you have solid measurements proving otherwise, you assume any Schiit product is incompetently engineered.

Yes you are 100% correct... they are assumed absolutely incompetent by incompetents! The measurements speak for themselves. You can use them to make judgment if you accept them or not, but they do not imply incompetence.