Toslink - Lightpipe Cables for DAC1, KSP8 and 002, Recommendations needed?

[leon]

Toslink cables to hook into the KSP8, 002 and DAC1.

Is it time to invest in a high end cable or will a lower end Hosa or Monster Standard give the same results with short 3' lengths? Recommendations?

Thanks Sluts!

[Albert]

You need to read the aftermarket power cable thread!

I use Hosa and it sounds okay to me. I'm assuming you mean 3 foot length, not three inches. They don't cost that much, so perhaps you should just buy one and see how it sounds to you.

[leon]

3' it is, I corrected it. Thanks. That aftermarket power cable trend is great but geared at AC power cables.

I do have Hosa cables but thought maybe it's time to go for a higher quality cable. Before I spend the bucks I'd like to hear from more sluts!

[Frost]

First, you can note that I do believe in high end cables so you can take from this post what you like. However, I have been using sound professionals glass toslink cable for my lightpipe duties for a while now and found it to make a big difference. The top end has a lot more clarity and seems to extend a lot further. Everything just feels better. I find I need less EQ on the top end.

Now if this cost $600 to achieve I would say buy a decent pre or mic or other slutty thing. However, they cost like $50. I cant recommend this $50 expense enough. Simply put, glass transmits light a lot better than plastic.
Frost

[leon]

I don't mind spending $50 pr cable even for a slight audible difference. Any particular ones?

[Frost]

http://www.soundprofessionals.com/cg...plate=homepage

the sound professionals offer the most bang for the buck. I found the wireworld were slightly better tho at 3x the price, and the sonicwave are supposed to be very nice as well ($80). I would buy the sound professionals as the differences to other glass cables were small and the price is right.
Frost

also, the glass cables tend to be a lot more flexible than the plastic variations.

[cdog]

Is this a jitter issue? I can see how glass transmits light better than plastic, but I was under the impression the cable itself can't introduce jitter, it either works or doesn't. Please elucidate me otherwise with pretty graphs and charts showing the jitter, frequency response or some other measurable difference.

[De chromium cob]

Hosa makes a better model lightpipe with metal ends and a heavy duty jacket that seems better built then the monster lightspeed stuff for half the price. Worth checking out....

[edmann]

I think no matter what, you should BNC-WC all litepipe connections

[Frost]

"Is this a jitter issue? I can see how glass transmits light better than plastic, but I was under the impression the cable itself can't introduce jitter"

I dont have any data, the only jitter study I ever did was at college where we looked at transport jitter and how changed both the jitter data and sound...

However, I know that improper impedence or less than perfect impedence can add jitter in a s/pdif line. Cable reflections can also add jitter. I would assume that the lower bandwidth of plastic would add jitter compared to a better polished glass fiber.

As for the BNC, I totally agree but lots of 001 or rme users dont have a wc input.

Frost

[edmann]

here we ago again..... (btw I am learning about this too)

according to digi-master Bob Katz - the jitter problem with litepipe occurs inside the box - at the point where the digital signals are converted to optical - -meaning that litepipe itself is doomed to less-than-accurate functionality. As I recall BK also indicated that the cable itself has no effect on jitter

To a lesser degree (I think...) the same goes for AES, as XLR connectors are not 110 ohms (i.e. wrong impedance)

S/PDIF would appear to hold more promise, as 75 ohm RCA connectors do exist....

BK speaks of the ideal digital transfer system, which is coaxial BNC based, using parts that are impedance matched, etc - this I assume to be a custom-made solution including physically modifying existing hardware

Bob Katz's site:

http://www.digido.com

[leon]

This is getting too intense for my little old setup. From what you say, if I'm doomed anyway, why bother with fancy smancy cables? No way I'm modifying existing equipment.

This is interesting stuff but I'm not sure how much it really matters for my simple setup, 002, KSP8 and DAC-1.

I've recorded about 50 records in the past 10 years with 3 ADAT's and an 02R with standard lightpipe I/O and had no problems, maybe the audio could have been a little better but how much better with high end cables or modifications, what are we talking - 1%, 5% maybe 20%???

If a cable can give me an improvement of say 5-20% difference in sound I would spend any amount of money, if we're talking 1-4% I'd cap the $ at $50 and if we're talking 25-50% I'd modify my equipment and go for broke!

Anyone have any statistics?

[edmann]

I am guessing that the difference is more like in the 20+% region......but again this can be reduced (so they say) by using BNC WC - and perhaps the same goes for ADAT multipin sample-accurate sync - does the 002 have that?

You might be able to learn more from actual users on the KSP8 forum at:

http://www.yahoogroups.com

[Albert]

Originally posted by leon
3' it is, I corrected it. Thanks. That aftermarket power cable trend is great but geared at AC power cables.

Yeah, that was kind of a tongue -in-cheek comment!

As has been mentioned, word clocking your gear together via BNC WC is important. A three foot lightpipe run seems so short that I'm not sure if a glass lightpipe cable would make much difference. I can see how it could potentially make a difference on longer runs though. I haven't used glass lightpipe cables though, so there may be a difference and I just haven't heard it.

I've used those more pricey Hosa lightpipe cables with the fancy ends and thicker cabling, but I don't think they are worth it. As a matter of fact, the only lightpipe cable I've ever had break down on me was one of those. Now I just use their thin basic model.

Leon, if your setup sounds good to you now then stick with it. If there is something in the sound that is bothering you, that is leading to you to want more expensive cables, then spend the money. It should be based on whether you are hearing artifacts or audio that you don't like. For me, my Hosa lightpipe cables sound fine (although I am curious about the glass cables now).

[cdog]

Quote from Bob Katz's Mastering Audio:


"...the bit integrity is perfectly acceptible on a plastic Toslink interface as long as the lengths remain under 5 meters...

Glass fiber has much less loss [of bit integrity over distances] than plastic, and can transmit for thousands of feet; it also has superior bandwidth and therefore causes fewer interface jitter problems, jitter as low as any good copper connection."

I'm going to buy some glass Toslink and do some basic tests, although I do not have a device to measure jitter. Will let you all know the results.

[edmann]

as I recall, the integrity of the signal once it is into the pipe is only half the story. The other half - which is elusive to me also at this point - is exactly how much jitter is introduced at the conversion-to-optical stage......that is something that is talked about a lot, and usually the reason sighted for opting AES over litepipe....

[leon]

Originally posted by cdog
Quote from Bob Katz's Mastering Audio:


"...the bit integrity is perfectly acceptible on a plastic Toslink interface as long as the lengths remain under 5 meters...

Glass fiber has much less loss [of bit integrity over distances] than plastic, and can transmit for thousands of feet; it also has superior bandwidth and therefore causes fewer interface jitter problems, jitter as low as any good copper connection."

I'm going to buy some glass Toslink and do some basic tests, although I do not have a device to measure jitter. Will let you all know the results.

I'd be interested in the results. Let us know! I'm probably gonna order the $50 SoundProfessionals cables and go from there.

[cdog]

Interesting jitter related material:

http://www.digido.com/portal/pmodule...der_page_id=52

http://www.nanophon.com/audio/towards.pdf

http://www.nanophon.com/audio/jitter92.pdf

http://www.benchmarkmedia.com/appnotes-d/jittercu.asp

[cdog]

Bob Katz's skinny:

This is ultimately a jitter question, you know. My answer is that the apparent sonic differences between interface technologies such as Toslink, glass, and copper are IRRELEVANT when doing transfers or when passing signal from one processor to another. You can forget about that question with COMPLETE CONFIDENCE----since all of the technologies are capable of passing perfectly good data, within their specified cable lengths. Remember: the clock is not transferred along with the data. Only the data is transferred to the processor's circuits.

The apparent sonic differences between interface technologies come into play in only ONE place.... and that is at the input to the converters (A/D and D/A).

If the D/A is susceptible to jitter on its digital inputs (as most are), then you will hear differences between toslink (plastic fiber), glass fiber, and copper (hard wire). Some D/As reject jitter better than others, and that will determine the extent you can hear these differences. REMEMBER: This is only important to that particular listening session (the D/A only) and not to any other circumstance.

In the case of an A/D, if placed on internal sync, then its jitter (and subsequent distortion) is totally determined by its internal clock ciruits. But if you have to lock an A/D converter with external "AES" sync, the interface technology chosen may affect the stability of the A/D. Locking an A/D with wordclock produces far less jitter because there is no audio on the wordclock line, it is a pure clock. Wordclock is the second-best way to lock an A/D short of using internal sync. In the case of AES/EBU, the audio and clock are on the same line, and the audio (and other data) can cause interference during the critical clock extraction process. The different technologies (toslink, glass, copper) have different bandwidths, and reduced bandwidth (as with plastic fiber) can cause greater interface jitter.

In any case, it is preferable to put the A/D on internal sync for the lowest distortion.

Only by placing the master clock of the entire system within the D/A converter and feeding all devices as slaves to that clock can we eliminate these "ephemeral" differences. That way the D/A is immune to clock-induced problems on its AES or SPDIF inputs.

How can we reconcile this issue of requiring the master clock be inside the DAC, yet the A/D has to be on internal sync for lowest distortion? You can only have one master clock in a system. The answer is to design an INTEGRATED A/D and D/A system where the master clock is on a buss, feeding all the critical internal jitter-sensitive elements with a low-jitter buss-interface.

That's what I've done recently in my system and I can attest that the "ephemeral" sonic differences have disappeared. (sigh of relief). At this time, I believe that integrated A/D/A systems with this technology can currently only be obtained from two vendors, TC Electronics (System 6000) and Prism. A consumer company called "Muse" has also adapted this technology on the consumer side, so there is hope. But it is sad and ironic that the audio industry has been so slow to adopt this technology, when the problem and solution have been known for years.



Hope this helps,

Bob

[leon]

This is some serious stuff here and all I ever wanted was a simple cable upgrade. The things one learns here. Good Links too. Thanks!