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Couple more premium CAT-7 cables, for those curious.

208.47.202.254

Posted on July 29, 2015 at 13:52:42
carcass93
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Posts: 7181
Location: NJ
Joined: September 20, 2006
Besides Audioquest and Supra, mentioned in M. Lavorgna's post below, I found couple more "outrageously" priced CAT-7 cables, produced by the companies associated with audio:

Oyaide (Japan)

Inakustic (Germany)


Relevant discussion in Linn forum, with some more cables mentioned (posts by HiViUser):

Linn forum


Anything else out there? Let's share.

 

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RE: Couple more premium CAT-7 cables, for those curious., posted on July 29, 2015 at 14:05:58
Sprezza Tura
Audiophile

Posts: 4585
Location: New York City
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Much appreciated.

These look interesting, but I wonder how US customers can even try these cables. Just too pricey to buy and hope.

Unless can post any sources that allow auditions.

At least the AQ cables are available from Magnolia for 14 days risk free.

 

Added a link to Linn forum discussion - have a look., posted on July 29, 2015 at 14:09:20
carcass93
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As far as audition goes - I believe that falls into SOL category for all of us :-).

 

RE: Couple more premium CAT-7 cables, for those curious., posted on July 29, 2015 at 14:12:27
You can also buy the AQ cables from Amazon which gives you a 30-day trial period.

 

RE: Added a link to Linn forum discussion - have a look., posted on July 29, 2015 at 14:27:50
Sprezza Tura
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Indeed. At least it is good to have the information at our fingertips.

 

RE: Couple more premium CAT-7 cables, for those curious., posted on July 29, 2015 at 14:28:13
Sprezza Tura
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Posts: 4585
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I did not know that. Thanks.

 

I going to wait for Cat 9 ...................nt, posted on July 29, 2015 at 15:26:00
Cut-Throat
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Contributor
  Since:
May 16, 2021
nt



 

RE: Couple more premium CAT-7 cables, for those curious., posted on July 29, 2015 at 18:47:59
Bob_C
Audiophile

Posts: 2667
Location: NY
Joined: July 31, 2000
Hi Michael,

A 30 day trial makes perfect sense.

I would like to say I really appropriate yours and Steve's honest real life reviews. They are always a pleasure to read and make sense.

No broken networks in your house! :)

Regards
Bob

 

RE: Couple more premium CAT-7, posted on July 29, 2015 at 23:35:28
unclestu
Dealer

Posts: 5851
Joined: April 13, 2010
Military uses reflectometers to gauge cable efficiency. It can detect things like a kink or pinch in the layout, and other anomalies which will affect performance. Hook up the machine and it will tell how far from the source the issue lies.

I've seen it in action and a simple overtightening of the wire bundles can create issues ( at least on the 688 class nukes)

I believe it behooves audiophiles to bear in mind that even cat 5 will suffer if zip tied too firmly. The cables must be treated with kid gloves, so to speak, in order to maximize performance.

 

RE: Couple more premium CAT-7, posted on July 30, 2015 at 02:50:39
Ryelands
Audiophile

Posts: 1867
Location: Scotland
Joined: January 9, 2009
Military uses reflectometers

Network installers I used to hire for small commercial projects about 20 years ago using then SOTA Cat5 cabling used a portable reflectometer of some sort on every cable they laid. See link for what seems a good explanation of why there's more to LAN cabling than many seem to grasp. (Thanks to whoever first posted it; someone please tell Lucy the title isn't mine.)

Of course, it doesn't necessarily follow that the issues discussed degrade sound or that, if they do, you have to spend AQ money to address them . . . but my Meicord "audio grade" LAN cable stays put.

 

RE: Couple more premium CAT-7 cables, for those curious., posted on July 30, 2015 at 03:17:50
soundchekk
Audiophile

Posts: 2424
Joined: July 11, 2007
If you start playing around with ethernet cables, you might also start playing around with the power supplies of your router and the routers itself.
Been there done that.

You can also hook up a one-foot cable to a small router which acts as wireless bridge or use an active ethernet-hub right in front of your transport. Don't forget to power that router or hub properly.
Been there done that.

It's gonna be a never ending story. Everything can make a difference as long as we have poorly implemented DAC interfaces out there.


In 2011 I wrote an article about my networking experiences:

network and audio

Most of what's written over there is still valid.

The "unshielded" Meicord cables did a great job in my case.

Good luck.

-----------------------------------------------------------------

blog latest >> The Audio Streaming Series - tuning kit pCP

 

RE: Couple more premium CAT-7 cables, for those curious., posted on July 30, 2015 at 05:18:46
Hi Bob,

Thank you. Steve does a great job, imo, dealing with many subjects most people would shy away from. He's taken a lot of heat because of it but he always stays cool ;-)

Cheers,

 

RE: Couple more premium CAT-7, posted on July 30, 2015 at 07:09:02
AbeCollins
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Contributor
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February 2, 2002
You can build your own basic Time Domain Reflectometer (TDR) with a pulse generator, oscilloscope, knowledge of the cable's velocity factor, and some math. Injecting a fast rise time pulse into the transmission line (cable) while measuring the time delay of the return signal can reveal impedance variances (sharp bend or kink for example), open circuits, short circuits, and the distances at which they occur.

The fast rise time pulse generator can be a commercial square wave generator, function generator, or a simple circuit that can be built for a few bucks. Cable manufacturers often provide the signal propagation delay spec (velocity factor) for the cable or it can be derived from other provided specs like dielectric constant, capacitance per meter, inductance per meter.

A commercial TDR can help to automate cable testing and perform the math for the operator.



 

Another application for TDR :-), posted on July 30, 2015 at 08:10:10
Tony Lauck
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Posts: 13629
Location: Vermont
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The first Ethernet controller that DEC sold worked on the fat (RG-8U compatible Triax). The controller included a built in Time Domain Reflectometer that could give an approximate location of a cable fault.

One of the early customers for these devices was Sandia National Laboratory. They put some of their test equipment into a hole in the ground together with a PDP-11 minicomputer that had the Ethernet adapter. The instrumentation was intended to measure the performance of an underground nuke. Here the high speed (10 Mbps in the early 80's) allowed more data to be sent before the computer and related equipment ceased to exist. (This was a source of ongoing computer business for us.)

The people from Sandia liked the TDR capability of the Ethernet controller that was in another PDP-11 safely above ground. After communication with the underground system was gone they ran the TDR and got the length of the remaining coax. This provided a quick and dirty indication of the success of the blast. :-)

Tony Lauck

"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar

 

It all makes sense - except for the mutilated dead horse that is "poorly implemented DAC interfaces"., posted on July 30, 2015 at 08:34:53
carcass93
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Posts: 7181
Location: NJ
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You see, expression "poorly implemented DAC interfaces" only makes sense in the context of "properly implemented DAC interfaces". I'm sure that's no different in German.

So far, there has been no evidence whatsoever that complete independence of SQ from particulars of incoming stream is even possible. And, that's with 2 completely different input streams and protocols - USB and Ethernet.

I have to conclude that root cause is not understood by anyone at the moment, despite proclamations to the contrary. The fact that Uptone USB REGEN improves SQ, but does not eliminate differences between USB cables, is pretty telling.

 

RE: Couple more premium CAT-7 cables, for those curious., posted on July 30, 2015 at 08:45:10
Ugly
Audiophile

Posts: 2912
Location: Des Moines, WA
Joined: August 22, 2006
I looked at part of the discussion on the Linn forum.

This is not a comment about whether (or not) the EMI from unshielded twisted pairs is worth worrying about.

Something I hadn't considered, didn't even realize affordable gear exists, converting to fiber will likely eliminate most all traces of harmful EMI from the transmission media to even lower levels than STP. It's rejection of typical EMI problems ought to be pretty stellar as well.

 

RE: Couple more premium CAT-7 cables, for those curious., posted on July 30, 2015 at 09:02:47
Bob_C
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Posts: 2667
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"Something I hadn't considered, didn't even realize affordable gear exists, converting to fiber will likely eliminate most all traces of harmful EMI from the transmission media to even lower levels than STP. It's rejection of typical EMI problems ought to be pretty stellar as well."

If you are interested, there are some good threads on Computer Audiophile about using fiber, and the results people have obtained. It is a good idea IMO, and not that costly.

 

RE: I going to wait for Cat 9 ...................nt, posted on July 30, 2015 at 10:01:56
jec01
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Posts: 1462
Location: Baltimore, Maryland
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Be careful what you wish for.

Happy listening,

Jim

"The passage of my life is measured out in shirts."
- Brian Eno

 

RE: It all makes sense - except for the mutilated dead horse that is "poorly implemented DAC interfaces"., posted on July 30, 2015 at 10:36:14
Tony Lauck
Audiophile

Posts: 13629
Location: Vermont
Joined: November 12, 2007
"So far, there has been no evidence whatsoever that complete independence of SQ from particulars of incoming stream is even possible. And, that's with 2 completely different input streams and protocols - USB and Ethernet."

USB and Ethernet are both extremely complex packet oriented interconnects requiring protocol processing, i.e. a computer of sorts inside of the DAC. Being packet oriented, both have periodic processing that takes place at audio frequencies, making it easy for noise to couple into critical analog circuitry. It is not at all surprising that they have similar problems. (Ethernet enjoyed a pure image in audiophile circles until recently, just because it wasn't being used for home audio.)

Most DAC designers have not made a serious effort to provide isolation. Doing so requires multiple circuit boards, multiple power supplies and special signal isolating/reclocking circuitry in between. What makes it so difficult is that one has to work at the physical level of signals on PC traces and ground planes, at the device level (transistors), at the logic level, and at the overall system level. Furthermore, because there is no known way to measure what is going on and correlate it to what audiophiles are hearing, the problem can't really be treated as an engineering problem today.

In the case of the Ethernet and USB chips the problem is further complicated by the existence of proprietary complexity inside the chips that is designed to meet "digital" specifications, without regard to the fact that these chips might be close to critical analog components.






Tony Lauck

"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar

 

RE: It all makes sense - except for the mutilated dead horse that is "poorly implemented DAC interfaces"., posted on July 30, 2015 at 12:32:01
Sprezza Tura
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The REGEN was designed on the very premise that all the problems are at the DAC receiver end and that the notion of "galvanic isolation" is marketing.

I don't entirely agree. I think there are just as many problems at the USB source end especially far more with personal computers..

 

It all makes sense - I have, posted on July 30, 2015 at 13:00:46
fmak
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Posts: 13158
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been saying this for years here. It seems that no audio system, analog or digital, is cable and interface independent.

No system is power supply quality independent either.

I note that Gordon is now being quoted by AQ as recognising the effects on SQ of power supply and signal integrity at the usb interface.

The usb guys have been attacking spdif to get their products going. Now they finally have to admit that the usb is as susceptible to interferences as anything else. Likewise LAN.

 

Isolation?, posted on July 30, 2015 at 13:09:51
fmak
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This does not work in the simplistic way that is perceived ie better isolation means better sound quality.

In the case of usb audio transfer, isolation of the I2S signals often rely on chips or components that actually increases jitter. Relocking also rely on chips that are not sufficiently tightly spec'ed to ensure uniform signal integrity ie one output of a flip flop can sound quite different from another.

I have not heard any optical isolator that sounds better either, with the exception of some Audio Research preamplifiers.

 

Optical - Cool!, posted on July 30, 2015 at 13:12:45
Bromo33333
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It is interesting as the limits of twisted pair go away, and as people hook up to optical fiber in their homes, for a hard"wired" connection, why would you want to go electrical if you don't have to?
====
"You are precisely as big as what you love and precisely as small as what you allow to annoy you." ~ R A Wilson

 

RE: Isolation?, posted on July 30, 2015 at 14:08:14
Tony Lauck
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Posts: 13629
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Isolation does not improve sound quality. It removes deterioration in sound quality caused by extraneous noise. If done successfully, sound quality will not change with changing bit perfect digital sources, but that's not enough. The constant sound quality must also be excellent.

As you correctly point out, some of the isolator circuits may remove external noise, but generate their own effects. They have to be reclocked, or more precisely buffered in a flip flop or shift register and some fancy footwork needs to be done with the clock phases. It's possible to design a shift register that will attenuate the variations in signal level and timing by buffering, and were it not for power and ground leakage, this could be made arbitrarily large through adding additional stages to the register. However, once the effect of power and ground come into play the idealized circuit and transistor design meets physical reality. Some of the isolators have ugly RF modulators in them, to generate an AC signal that can be sent through some kind of isolation network. I suspect that a better approach is to eliminate the DC component by using Manchester code. The Manchester encoders and decoders require a minimum of digital logic and can use readily available pulse transformers. Several stages of "isolate and then buffer/reclock" can be repeated if needed. But note that there isn't really any reclocking because all of these stages are synchronous with the main DAC clock.

One thing that's nice about DSD is that there are no clock signals that are running anywhere near the audio band, provided that everything can be kept streaming. (No damn packets or pseudo PCM format kluges.) So in this case, the interconnect is more akin to the SDIF variations. I see no need for a DAC to do anything but accept DSD at one suitably high rate. This further reduces the amount of digital logic that is anywhere near to the critical mixed signal and analog circuitry and all the circuitry can be tuned to one sweet spot.


Tony Lauck

"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar

 

RE: Optical - Cool!, posted on July 30, 2015 at 14:09:46
Bob_C
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""why would you want to go electrical if you don't have to?""

If you are saying... Why not just use fiber... There are issues with everything you do. With fiber you need to add the converters and good power supplies for them, unless you can put a fiber channel card in the system. And then a fiber switch etc. Have not tried it yet, but eventually probably will.

I have been pretty happy with the improvement that the Ethernet filter, linear PS on NAS, router and switch and CAT 7 provided.

 

RE: It all makes sense - except for the mutilated dead horse that is "poorly implemented DAC interfaces"., posted on July 30, 2015 at 19:18:25
Ugly
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Posts: 2912
Location: Des Moines, WA
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"So far, there has been no evidence whatsoever that complete independence of SQ from particulars of incoming stream is even possible"

Of course not. There never will be unless you are god. Everything in this universe is linked and there is chaos all around. There are only varying degrees of better or worse. The best anyone can hope to do is reduce the effect of the most annoying thing on the list somewhere so far below the next most annoying thing on the list it is no longer significant in comparison, repeat and don't give up until you hit an asymptote.

 

It's worse than that..., posted on July 30, 2015 at 20:25:10
Ivan303
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It's possible to make a number of changes that in and of themselves, make no perceivable change/improvement in SQ, but the sum of those changes may end up improving the sound. =:-0



First they came for the dumb-asses
And I did not speak out
Because I was not a dumb-ass

 

DSD, posted on July 30, 2015 at 23:45:45
fmak
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impulse reponse and lack of a brickwall filter play their parts

 

RE: Isolation?, posted on July 31, 2015 at 02:09:09
soundchekk
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There are many DACs that come with "isolation". It's still not sufficient.
Because there are more than one issue associated to USB.

The isolation is usually run on the I2S. And that's just isolation.
The typically used XMOS chip and its surroundings acts as open door to the noise, data-jitter, clock interferences and modulations, EMI/RFI, reflections/impedance issues, crosstalk, you name it. (That's why Steve Nugents famous words " It's all common mode noise" must be considered nonsense.)

iFi claims 5db noise reduction with the iPurifier. That's not covering the whole subject. They also sell split cables to cover some crosstalk effects. The USB-Regen covers some data/packet-jitter effects by reclocking the stream with a reasonable quality clock on a hub-chip. They also apply filtering and claim that their ground filtering method is very effective. They address ground loop issues this way.
Obviously the bits get properly refreshed with the Regen. Cones become rectangles again.
However. People claim that there are still cable issues (impedance?),
and that e.g. better clocks and power supply improve the Regen even further. I'd expect that we see a Regen2 sooner or later. However.
As an external device, the Regen will never be the perfect solution.



I do also think that pretty non-linear buffer-jitter (buffer - read/write/clear) might cause issues. Obviously that's less with asynchronous USB.
I doubt that it 100% disappears though. What I'm saying here is that
the firmware and drivers shouldn't be neglected.

To me all these issues are basic engineering issues. And should be known to a capable DAC designer. Many of these are addressed to a certain extent of course. I doubt though that these issues are sufficiently addressed. That's at least what the e.g. the Regen shows.

My advise.

Dear Manufacuters (That includes Empirical Audio, Ayre, asf.).

Buy yourself a USB-Regen and check your device performance with or without it. After that you'd know what to do.
Especially these companies that ask several thousand $ for a device
can be expected to implement this or that measure. I mean a Regen in parts might cost $20 max.

You might also get in touch with XMOS to discuss the issues.

Thx



-----------------------------------------------------------------

blog latest >> The Audio Streaming Series - tuning kit pCP

 

RE: Optical - Cool! -Fibre, posted on July 31, 2015 at 07:46:18
fmak
Audiophile

Posts: 13158
Location: Kent
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is electrical. The optical bit is embedded.

 

RE: Isolation?, posted on July 31, 2015 at 10:14:53
Bob_C
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Joined: July 31, 2000
It is such a pleasure to have someone here that knows so much... What we we do without you...

 

ANother, posted on August 1, 2015 at 00:00:25
fmak
Audiophile

Posts: 13158
Location: Kent
Joined: June 1, 2002
who know so little about audio, who spends a lot based on fad, and who makes the loudest noises here.

 

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