You are here

Log in or register to post comments
SAS Audio
SAS Audio's picture
Offline
Last seen: 9 months 2 weeks ago
Joined: Jun 6 2007 - 6:56am
Re: A very interesting article in Audio Xpress

Hi Buddha,

Well I could not find any more information on the player, no response from the manufacturer, but I would consider less than 500 ohms output impedance normal. Others I have seen have been less than 100 ohms, but I believe you stated the component has been modified, so it could be higher.

Anyway, 100khz seems more difficult to comprehend than 20khz so I produced some data at 20khz using cirmaker.

Output Impedance (Z)----Capacitance-----DB change

2k ohms-------------------250pf cable--------0.017 db down
1k---------------------------250------------------0.0045 db
500-------------------------250-------------------0.001 db

2k ohms-------------------475pf cable--------0.061 db down
1k---------------------------475-----------------0.016 db
500-------------------------475-----------------0.004 db

One can compare the loss using each cable at 20khz and see the change is quite small. For instance at 1k ohms output Z, the change caused by swapping cables is approximately .0115 db.

Hope this helps Buddha.

Steve

SAS Audio
SAS Audio's picture
Offline
Last seen: 9 months 2 weeks ago
Joined: Jun 6 2007 - 6:56am
Re: A very interesting article in Audio Xpress

Hi Michigan,

How many back and forths (ABs) before

Quote:
it all starts to blend together

Thanks.

jneutron
jneutron's picture
Offline
Last seen: Never ago
Joined: Sep 16 2009 - 12:34pm
Re: A very interesting article in Audio Xpress

The simulation is great.

I fear that it assumes that all the return current is flowing though the shield of the IC.

At low frequency, it may be that most of the return current is via the line cord.

What is needed is to model the IC and PC as well as the I/O impedances and the characteristic impedance of the IC.

That'll provide the break frequencies for the return current..

Remember, a shielded cable does not shield if the current of the inner conductor does not return 100% via the outer shield..

Cheers, John

SAS Audio
SAS Audio's picture
Offline
Last seen: 9 months 2 weeks ago
Joined: Jun 6 2007 - 6:56am
Re: A very interesting article in Audio Xpress


Quote:
The simulation is great.

I fear that it assumes that all the return current is flowing though the shield of the IC.

At low frequency, it may be that most of the return current is via the line cord.

What is needed is to model the IC and PC as well as the I/O impedances and the characteristic impedance of the IC.

That'll provide the break frequencies for the return current..

Remember, a shielded cable does not shield if the current of the inner conductor does not return 100% via the outer shield..

Cheers, John

On a side note, looks like a great example of exposing a flaw when using a simulator.

Yes, I learn a lot from you and thanks for the information John. Your information means things are a real crap shoot depending upon the component construction/design used. Would you explain further for us John?

jneutron
jneutron's picture
Offline
Last seen: Never ago
Joined: Sep 16 2009 - 12:34pm
Re: A very interesting article in Audio Xpress

Lets see.

250 pf for one meter, that is 76 pf per foot. If we assume a DC of 3, the inductance per foot will be:

L = (1034 *3)/76, or 40.8 nH per foot.

Z = sqr(L/C) or sqr(40,800/76)

Z = 23.2 ohms
(is that capacitance correct, this seems awfully low for an IC.

For the signal to return along the shield of the IC, it will encounter an inductance of 120 nH and the resistance of the IC shield plus contact resistances.

To return via the line cord, it has the two line cord resistances and the line cord pair inductances.

Two line cords spaced 24 inches apart has about 700 nH per foot inductance. Six feet would be 4.2 uHenries.

Figure #12awg, 1.2 mohm per foot, 12 feet, 14.4 milliohms, add say 3 milli per contact, 26.5 milliohms in series with 4.2 uHenries.

For the IC shield, use 40.8 nH(edit times 3, or 120 nH) in series with the IC cord, say 20 milliohms per foot, 60 milli's plus contacts, say 20 mils apiece..100 milliohms total.

So outgoing is the IC center wire, return is via two paths. The line cord will dominate lf, the coax will dominate hf.

Modelling possibility???

Cheers, John

ps..sorry, didn't add very well...duh

SAS Audio
SAS Audio's picture
Offline
Last seen: 9 months 2 weeks ago
Joined: Jun 6 2007 - 6:56am
Re: A very interesting article in Audio Xpress

Thanks John. I copied the specs from Purist anniversary ICs. Here is a copy and paste.

Shielding: Polyester Wrap, Braided Silver-Plated Copper with 90%Coverage, & CONTEGO
Dielectric: Teflon

jneutron
jneutron's picture
Offline
Last seen: Never ago
Joined: Sep 16 2009 - 12:34pm
Re: A very interesting article in Audio Xpress

Ah thanks.

+/- 15 % on the capacitance?? That seems like a rather large deviation. It would seem that they are hand braiding the cables, they don't have control over their dielectrics to better than 15%, or they need help with their capacitance meter.

The resistance numbers came up gobbledygook. What were the resistances?

With all the numbers in hand, it should be easy to model the currents between the IC and the PC, no?

ps..when they say single ended, is that an entirely different cable, are they using only one inner conductor of a dual, or are they tying both inners together?

Cheers, John

SAS Audio
SAS Audio's picture
Offline
Last seen: 9 months 2 weeks ago
Joined: Jun 6 2007 - 6:56am
Re: A very interesting article in Audio Xpress


Quote:
Ah thanks.

+/- 15 % on the capacitance?? That seems like a rather large deviation. It would seem that they are hand braiding the cables, they don't have control over their dielectrics to better than 15%, or they need help with their capacitance meter.

The resistance numbers came up gobbledygook. What were the resistances?

With all the numbers in hand, it should be easy to model the currents between the IC and the PC, no?

ps..when they say single ended, is that an entirely different cable, are they using only one inner conductor of a dual, or are they tying both inners together?

Cheers, John

Your last question, I don't know John.

The capacitance variation of +/-15% would seem to indicate what you stated.

Shielding: Polyester Wrap, Braided Silver-Plated Copper with 90%Coverage, & CONTEGO
Dielectric: Teflon

geoffkait
geoffkait's picture
Offline
Last seen: 2 hours 18 min ago
Joined: Apr 29 2008 - 5:10am
Re: A very interesting article in Audio Xpress

Has anyone mentioned Purist cables are cryogenically treated? Actually cryogenically treated in a controlled magnetic field - CryoMag.

One wonders if that affects the parameters being measured?

Buddha
Buddha's picture
Offline
Last seen: 3 years 1 month ago
Joined: Sep 8 2005 - 10:24am
Re: A very interesting article in Audio Xpress


Quote:
Has anyone mentioned Purist cables are cryogencially treated? Actually cryogenically treated in a controlled magnetic field - Cryomag .

One wonders if that affects the measurements?

Man, if only there were a way to answer that question.

Assuming, of course, that "cryogenically treated in a controlled magnetic field" means anything in particular. Guess it would be interesting to see what the actual treatment protocol is, as well.

(Probably 'proprietary.')

With the loose use of language in this hobby, that could mean anything from holding them in your arms as you walk between a Kenmore and an un-demagmagentized LP all the way industrial style cryogenics and actual magnetic fields.

geoffkait
geoffkait's picture
Offline
Last seen: 2 hours 18 min ago
Joined: Apr 29 2008 - 5:10am
Re: A very interesting article in Audio Xpress

Quote:
------------------------------------------------------------------------
Has anyone mentioned Purist cables are cryogencially treated? Actually cryogenically treated in a controlled magnetic field - Cryomag .
One wonders if that affects the measurements?

------------------------------------------------------------------------
"Man, if only there were a way to answer that question.

Assuming, of course, that "cryogenically treated in a controlled magnetic field" means anything in particular. Guess it would be interesting to see what the actual treatment protocol is, as well.
(Probably 'proprietary.')"

With the loose use of language in this hobby, that could mean anything from holding them in your arms as you walk between a Kenmore and an un-demagmagentized LP all the way industrial style cryogenics and actual magnetic fields.

Courtesy Positive Feedback Online: "The other feature is a treatment called Cryomag

Buddha
Buddha's picture
Offline
Last seen: 3 years 1 month ago
Joined: Sep 8 2005 - 10:24am
Re: A very interesting article in Audio Xpress


Quote:
Quote:
------------------------------------------------------------------------
Has anyone mentioned Purist cables are cryogencially treated? Actually cryogenically treated in a controlled magnetic field - Cryomag .
One wonders if that affects the measurements?

------------------------------------------------------------------------
"Man, if only there were a way to answer that question.

Assuming, of course, that "cryogenically treated in a controlled magnetic field" means anything in particular. Guess it would be interesting to see what the actual treatment protocol is, as well.
(Probably 'proprietary.')"

With the loose use of language in this hobby, that could mean anything from holding them in your arms as you walk between a Kenmore and an un-demagmagentized LP all the way industrial style cryogenics and actual magnetic fields.

Courtesy Positive Feedback Online: "The other feature is a treatment called Cryomag

geoffkait
geoffkait's picture
Offline
Last seen: 2 hours 18 min ago
Joined: Apr 29 2008 - 5:10am
Re: A very interesting article in Audio Xpress

"But, please, don't tell May about how actual cryogenic treatment is well documented and any different from wrapping something in a dish towel and tossing it in the Frigidaire, OK?"

Not sure I agree cryogenics is "well-documented" as there is some dispute over the actual *mechanism* involved - what change(s) to the materials actually improves the sound. Sure, the *process* is well-known, but why it improves the sound for audio items remains a bit of a mystery. For example, why does cryoing a CD or LP improve the sound?

In my experience, cryogenics and the home freezer are both effective methods of treatment and both are permanent. Now that I think about it, the home freezer treatment is well-documented, too. Just doesn't sit well with the, uh, "but the temperatures aren't low enough!!" crowd.

"Hey, it's one reason why we wanted to do the trial with their product, eh?"

So how does a cryogenically treated cable sound, eh?

Buddha
Buddha's picture
Offline
Last seen: 3 years 1 month ago
Joined: Sep 8 2005 - 10:24am
Re: A very interesting article in Audio Xpress

No problem.

It's a bit nippy here today so I left the furnace off and cryogenically treated my whole system while I'm at work.

The temperature in my house is well documented and the process of house cooling is well known.

If we could only get more people to listen at room temperatures of 64 degrees or lower! Electricity is actually conducted better at lower temperatures, which is well documented!

Anyway, I really like the Purist Audio products, and they are nice people, as well!

michiganjfrog
michiganjfrog's picture
Offline
Last seen: Never ago
Joined: Jan 9 2007 - 11:36pm
Re: A very interesting article in Audio Xpress


Quote:
Hi Michigan,

How many back and forths (ABs) before

Quote:
it all starts to blend together

Thanks.

I don't think it would help for me to say that, whether trying to speak in general, or for myself. It could be none, could be ten, could be three. Last night, for me, I think it was around 4 where I lost confidence and asked to stop the test, because I realized there was no point in continuing it, if I did not even know what I was supposed to be looking for. That's when I realized I should have done a pre-test to get myself acquainted with the sound of each condition, if I am to have any chance of getting right, beyond pure guesswork. I was a bit under a strain too, to hurry it up, because I was taking too long to make my guesses (I guess well over a minute -- what can I say, the sound was too musical!), and my partner was wanting to get it over with. So I did no better than 6 out of 10 that time.

michiganjfrog
michiganjfrog's picture
Offline
Last seen: Never ago
Joined: Jan 9 2007 - 11:36pm
Re: A very interesting article in Audio Xpress


Quote:
But, please, don't tell May about how actual cryogenic treatment is well documented and any different from wrapping something in a dish towel and tossing it in the Frigidaire, OK?

Have you ever actually put your cables through the proper domestic freezer process as May suggests, to be able to say that? That's a serious question, because while I've put mine through the freezer process to good effect, I have never compared them with the same version cryo'ed to be able to say whether it is any better, in terms of improving the sound. I'm not sure it would be.

One wonders if that affects the measurements?

Man, if only there were a way to answer that question.

I was attempting to have that sort of question answered on a forum some years ago, if you might recall, when I did what I called my "Big Freeze Test". Where I uploaded unidentified files that were sourced from one frozen CD and one not frozen CD. Before I could get to post the results, the forum's wise and friendly moderator stepped in and put the kaibosh on all of that, when he deleted three quarters of the member's test results just before I was about to announce the results. And people were analyzing these files every possible way; bit - checksum comparisons; putting them through waveform analysis software, subjective testing, etc. What I saw at the end was some very positive indications of objective differences in the measurements obtained, between the frozen and unfrozen versions of the files. When, according to the beanieheads, there should not have been any differences whatsoever. And we're just talking about files of objects that have gone through a domestic freezer process!

Long before that occurred, on another forum, I had advocated a tweak to my fellow members that involved putting their mp4 players through the domestic freezer process I defined. Yes, in a "dish towel" just like you described, fancy that! And yes, it is exactly the process that May Belt advocates, the one her husband discovered some 25 years ago. Many wrote to say their sound had improved. But as I recall, at least one found physical differences where the player showed a marked reduction in noise and distortion. Another put up before and after test files himself, and ran the whole thing through waveform analysis, citing differences in the before and after conditions. From this, I would be surprised if it wasn't possible to measure objective differences with the cryogenic technique, one way or another. It certainly isn't difficult to do. Offhand I don't know of any such tests, but I have no reason to believe these measurements have not already been done, with as many companies today that are using cryogenic techniques for their products.

So that's why I ask; what do you know about the differences in sound quality, from home freezing vs cryogenics? I know there are physical and theoretical differences, but that doesn't tell me about the actual result of each process in terms of sound.

May Belt
May Belt's picture
Offline
Last seen: 11 hours 14 min ago
Joined: May 8 2006 - 1:51am
Re: A very interesting article in Audio Xpress

>>> "But, please, don't tell May about how actual cryogenic treatment is well documented and any different from wrapping something in a dish towel and tossing it in the Frigidaire, OK?" <<<

I will repeat, yet again, as I have done endlessly over these last 25 years.

After discovering that he could improve the sound of all the different metals he was experimenting with. when used as conductors. by annealing them (baking them in our gas oven - as described by Martin Colloms in his excellent articles "Cable Controversy" in 1984), Peter found that as soon as he put ANY plastic insulation around the bare metals, the sound deteriorated !! He knew that he could not similarly 'cook' the plastic insulation materials in the gas oven so he decided to try the opposite - to freeze them in our domestic deep freezer. After doing so and allowing the plastic materials to return to room temperature very, very slowly, he found that, this time, applying the plastic insulation to the bare metals had nowhere near the same adverse effect on the sound !! So, after annealing the metals, he tried the same freezing/slow defrost technique with the bare metals with further beneficial results to the sound - from the SAME metals !!!!!

We have always stated from the very start. We never intended the subject (of freezing) to be a "shooting match at the OK Coral" between using a domestic deep freezer or using the much lower temperatures of cryogenic freezing. We told people of the simpler freezing/slow defrost technique using a domestic deep freezer so that people could try that simple technique, easily, for themselves !!!!!! And, then, in common with so many people who HAVE tried that technique they might gain significant improvements in their sound. Thereby showing that there is much more musical information, already there, available, to be experienced !!

I am not a numbscull, Buddha. I DO know the difference between the temperature of a domestic deep freezer and the temperature of the cryogenic freezing technique !!!!!!!!!!!!!!
Mock all you want, Buddha.

Stephen, could we please adopt, as unacceptable, at least Steve Hoffman's guidelines of
>>> "opinions such as "that's stupid", "that's ignorant", "that's the dumbest thing I've ever heard", or "that's bullsh*t")."

Regards,
May Belt,
P.W.B. Electronics.

geoffkait
geoffkait's picture
Offline
Last seen: 2 hours 18 min ago
Joined: Apr 29 2008 - 5:10am
Re: A very interesting article in Audio Xpress

Cryogenics used to be considered voodoo for audio applications 10 and 15 years ago and is still considered controversial. There is even controversy over the actual "well-documented" process - with many companies claiming their "proprietary" methods, including direct immersion in the liquid nitrogen, superior to the others. Audio companies that employed cryogenics were often reluctant to publicly acknowledge its use - due to the perceived stigma or the (hopefully) technical advantage over companies that did not employ cryogenics. I have been using cryogenics for 15 years (as long as Jim Aud) for a variety of applications, including critical elements of my isolation systems.

So, now we have companies using cryo for such esoterica as tonearms, turntable platters, tonearm wire, electron tubes, metal fasteners, CDs, CD players, amplifiers, DACs, capacitors, chips, internal wiring for components, structural members of racks, aluminum/steel cone feet, etc.

jneutron
jneutron's picture
Offline
Last seen: Never ago
Joined: Sep 16 2009 - 12:34pm
Re: A very interesting article in Audio Xpress

If the cables are coiled too tightly during the cryogenic process, it is possible that the dielectric has cracked. Typically, it will do so on the outer side of the bends where it is in tension. This can easily be spotted by autopsy, or by a hi-pot test.

It is difficult for me to determine if 77
Kelvin is low enough to crack teflon and PVC in that geometry, as most of my experience is at 4.5 Kelvin and 1.88 Kelvin.

The metal will not undergo any transition which will be measurable per se.

If the braid becomes looser around the structure, then it is possible to impact strand jumping of the shield current. This will alter the high frequency performance of the cable such that the current centroids will have a more difficult time centering. High frequency being well above the audio realm of 20 to 20K, but I do not know if it exceeds the 2 uSec localization thresholds.

ps. Trashing the ability of the current to strand jump will only impact the high frequency inductance if the inner conductor is not centered within the braid. For a balanced configuration, the conductors are not centered by design.

Cheers,John

smejias
smejias's picture
Offline
Last seen: 4 years 6 days ago
Joined: Aug 25 2005 - 10:29am
Re: A very interesting article in Audio Xpress


Quote:
Stephen, could we please adopt, as unacceptable, at least Steve Hoffman's guidelines of
>>> "opinions such as "that's stupid", "that's ignorant", "that's the dumbest thing I've ever heard", or "that's bullsh*t")."


First of all, I don't see why such a rule should be necessary. Second, I think "That's bullshit" is in some cases an acceptable response. Of course, I do hope that anyone bold enough to make such a response will also be 1., bold enough to back it up and 2., willing to accept criticism in return.

geoffkait
geoffkait's picture
Offline
Last seen: 2 hours 18 min ago
Joined: Apr 29 2008 - 5:10am
Re: A very interesting article in Audio Xpress

Yes, I've noticed that certain plastics can crack and the surface coloration of some metals can change during -300 cryo. (This is why many customers cryo the wire only, prior to constructing the cable.) Nevertheless, cryo is relatively safe and effective for many audio apps. It should be noted that these potential problems with deep cryo are eliminated by using the home freezer - as I've mentioned, an easy, safe, free and effective alternative.

It might come as some surprise that the methodology for using the home freezer can get rather complex when taken to the extreme for audio applications.

As Newman used to say, when you control the mail you control... information.

jneutron
jneutron's picture
Offline
Last seen: Never ago
Joined: Sep 16 2009 - 12:34pm
Re: A very interesting article in Audio Xpress

Which metals changed color? I have not noticed this.

Then again, we only use helium gas to warm up anything until we exceed 77K, then we can use dry nitrogen. Never room air.

Cheers, John

geoffkait
geoffkait's picture
Offline
Last seen: 2 hours 18 min ago
Joined: Apr 29 2008 - 5:10am
Re: A very interesting article in Audio Xpress

"Which metals changed color? I have not noticed this."

Most notably brass, which turns darker and duller, an "antique brass" color. Kinda cool.

jneutron
jneutron's picture
Offline
Last seen: Never ago
Joined: Sep 16 2009 - 12:34pm
Re: A very interesting article in Audio Xpress

I see. Thank you.

Brass is of little use for me, as it does not have a thermal nor electrical conductivity which is useable for me.

Perhaps I will have some brass hardware bolted to the next item taken cold.

Any specific brass type, or will any do?

Cheers, John

geoffkait
geoffkait's picture
Offline
Last seen: 2 hours 18 min ago
Joined: Apr 29 2008 - 5:10am
Re: A very interesting article in Audio Xpress

I have used brass threaded rods for my 6 DOF Nimbus as well as heat tempered steel rods, at various times. The brass rods were the plain vanilla variety available at hardware stores. For critical installations I prefer large diameter rods, 2 feet long and one inch diameter, that are untempered steel.

Scott Wheeler
Scott Wheeler's picture
Offline
Last seen: Never ago
Joined: Sep 3 2005 - 7:47pm
Re: A very interesting article in Audio Xpress

Jeez, 8 pages on this thread. We have arguments about freezing cables and blind testing and not one actual practical suggestion about a real world connector that meets the article's prescibed needs for being an optimal connector. OK lets talk about some real world connectors and field some opinions on their qualites in light of the article JJ is talking about.

http://www.audiomania.com/shop/goods-6126.html
Use of machined solid silver (99.99% pure) for superior conductivity.
Patented design. Unique single point ground for eddy current reduction and enhanced signal integrity.
Extensive use of glass impregnated moulded polymers. Ideal resonance and electrical characteristics.
Unique hollow tube design for best possible signal transmission. Facilitates soldering at the conductor's tip for an even more direct connection.
Standard in black or blue polymer. Black or gold metal housings available by special order.
Currently used by over one hundred cable manufacturers.
Compatible with all RCA sockets.
Designed and manufactured in Brisbane, Queensland, Australia

http://www.audiogear.com/cgi-bin/shopper.cgi?key=NF2CB2&preadd=action

Item #: NF2CB2
Neutrik NF2CB-2 ProFi RCA Plug, Pair (N032)
Description: Neutrik NF2CB/2, This is the PRO-FI RCA plug, with gold contacts, a clutch type strain relief, movable external collar makes and releases the ground contact before the pin. This is probably the best RCA plug in the world today.
Our Price: $13.99

http://www.audiomania.com/shop/goods-6485.html
WBT 0102 Ag KIT (set 4 pcs) rca connector's product information
Contacts utilize passivated pure fine silver. The body is constructed with brass and then platinum plated to give a nice asthetic appeal. The central contact assembly is made of Ultramid and the negative contact uses Dyneon. The barrel is comprised of brass with a shiny black piano lacquer finish. A characteristic impedance of 75 ohms makes this a perfect match for digital audio and video. The maximum size conductor that can be used is 1.5mm

jneutron
jneutron's picture
Offline
Last seen: Never ago
Joined: Sep 16 2009 - 12:34pm
Re: A very interesting article in Audio Xpress

The wbt rca will not have a 75 ohm impedance once it is inserted into a standard rca jack.

All cables are transparent to magnetic fields within the audio realm.

And I do not understand why eddy currents are bad? What has eddie done to anybody?

Cheers, John

j_j
j_j's picture
Offline
Last seen: 2 years 6 months ago
Joined: Mar 13 2009 - 4:22pm
Re: A very interesting article in Audio Xpress


Quote:
The wbt rca will not have a 75 ohm impedance once it is inserted into a standard rca jack.

All cables are transparent to magnetic fields within the audio realm.


Not sure why you bother to mention characteristic impedence, since RCA connectors were never constant impedence of any sort, in practice.

Quote:

And I do not understand why eddy currents are bad? What has eddie done to anybody?

Cheers, John

Eddy currents can create frequency-dependent losses, and can also, in some materials (ferromagnstic ones), cause some nonlinearities.

Scott Wheeler
Scott Wheeler's picture
Offline
Last seen: Never ago
Joined: Sep 3 2005 - 7:47pm
Re: A very interesting article in Audio Xpress

So what do you think of the WBT connectors? Are they better? Are there some serious flaws you see in their design? Are they overkill? They certainly look to be well made at the very least.

jneutron
jneutron's picture
Offline
Last seen: Never ago
Joined: Sep 16 2009 - 12:34pm
Re: A very interesting article in Audio Xpress

I mentioned it because in Scott's post, it was mentioned as a selling point of the wbt connector.

It indeed does exhibit a 75 ohm impedance, and it does so by raising the inductance of the shield connection of the shell. This of course, is exactly what the other connectors avoid at all cost by the use of half a pound of copper or silver..

The only way for the connector to remain true 75 ohm, is if it is connected to the wbt female jack.

Um, jj? You need to adjust your humor sensitivity measurement device...it is set too low.

I kinda know what eddy currents are.. but thanks for the explanation anywhoo..

Cheers, John

jneutron
jneutron's picture
Offline
Last seen: Never ago
Joined: Sep 16 2009 - 12:34pm
Re: A very interesting article in Audio Xpress

They appear to be nice. If I were concerned about the overall conductivity of the shield connection, I'm not sure if they would be adequate. The lower the shield to amp conductivity, the lower the ground loop currents become, and that could increase noise and hum intrusion.. Of course, that would always be system dependent and it probably never has reared it's ugly head..

The 75 ohm thingy is not at all important to audio of course, as the length of the discontinuity in impedance is not anywhere near a wavelength. (above 5 orders of magnitude, say a coupla bazillion)..It would be ugly for a signal that had a riselength of a foot. (a nanosecond)

Cheers, John

j_j
j_j's picture
Offline
Last seen: 2 years 6 months ago
Joined: Mar 13 2009 - 4:22pm
Re: A very interesting article in Audio Xpress


Quote:
Um, jj? You need to adjust your humor sensitivity measurement device...it is set too low.

Well, you know, on a board with this population, it's kinda hard to know who is telling a joke intentionally ...

KBK
KBK's picture
Offline
Last seen: Never ago
Joined: Sep 30 2007 - 12:30pm
Re: A very interesting article in Audio Xpress

jn2 stands for 'Johnny Neutron', ver 0.2beta heh heh

He likes to do laps, like, really really fast. Then when he gets to the end, he gives the other guy a big headbutt. this results in a very nasty accident with shit spiralling off everywhere like an action movie carnage scene, where the hero barely makes it. They take photos of the scene and then show them to the crime scene physicists who try and pin the blame on Mr Higgs or whomever they feel is the big terrywrist for this year.

Orb
Orb's picture
Offline
Last seen: Never ago
Joined: May 28 2009 - 12:51am
Re: A very interesting article in Audio Xpress


Quote:

Quote:
I think that camera needs to be replaced, sheesh not only a strange matrix green but look at the quality, unless its a ghost convention (after all arent they meant to be moving specs-blobs of light)

Just kidding, although are you sure that in-room effect does not mess with your mind!!!

Cheers
Orb

You liked those orbs in the photo?

After a few tipples of sherry and a pint of Absinthe for sure

Cheers
Orb

j_j
j_j's picture
Offline
Last seen: 2 years 6 months ago
Joined: Mar 13 2009 - 4:22pm
Re: A very interesting article in Audio Xpress


Quote:
jn2 stands for 'Johnny Neutron', ver 0.2beta heh heh

Oh.
Rocket Scientist.

Gotcha.

Somebody who might actually have used some irridium plated contacts.

jneutron
jneutron's picture
Offline
Last seen: Never ago
Joined: Sep 16 2009 - 12:34pm
Re: A very interesting article in Audio Xpress

Matte gold finish only. No silver, no platinum, no iridium, no latinum....

After all, it ain't rocked science...

Actually, I've used silver plating, that copper paste goop, and indium at times. But the contacts I use are generally not the kind that are slip-insertion other than hypertronics connectors. Usually high grade stainless 1/2 inch bolting hardware, two for every 500 amps. In a pinch for space, we'll use titanium bolts and a 200 microinch finish...

jj...you mentioned gold oxide. Are you sure about that?? Perhaps what was actually being seen was the organic levellers on a shiny gold finish..

Cheers, John

absolutepitch
absolutepitch's picture
Offline
Last seen: 1 year 2 weeks ago
Joined: Jul 9 2006 - 8:58pm
Re: A very interesting article in Audio Xpress


Quote:
The level of distortion Ed found is not going to matter (well, the level of distortion with CLEAN contacts, let's be clear here... dirty contacts are another bird altogether) at high levels. It might intrude into phono or mike levels.

But dirty connectors (I mean properly inserted ones that have aged, not ones with mud poured on them) can be pretty nasty if they sit long enough. RCA connectors especially.

Sorry to jump in so late; been too busy.

No question about contact cleaning is important - absolutely right.

What I heard was a difference between the typical PVC coax cable with RCA terminations and a Teflon(R) dual conductor plus shield construction and RCA terminations.

The effect was less with pre-amp to amp than with the phono cable. The phono cable from the TT to the pre-amp has one end soldered. There is a short 2-3 inch segment in the tonearm that I replaced from PVC to Teflon, both ends soldered. The phono cable made 1/3 of the difference in sound, the shorter tonearm part made 2/3 of the difference. All changes to the sound was in the same direction of improvement. It was surprising to me to find this was so.

Yes, connector cleaning is important, and it seems to me the type of wire/insulation and soldering may also make some difference.

This is because I 'cleaned' the phono connector by inserting a new cable, then listened. Later I changed the tonearm part of the wiring, reasoning that if the phono cable makes a difference, the tonearm wire would also. Note, this included contact cleaning of plugging the cartridge connectors back onto the cartridge.

Unfortuantely, the results are confounded because the wire changed and both ends' connectors were 'cleaned' by removal and re-insertion. If the connector cleaning is a low level effect, and the audible effect is clearly noteciable, then the difference might just be the wire difference dominating, with a lesser role of the connector effect.

Too bad I didn't examine this further. Maybe you or someone else already has. I'd like to read Ed's article too.

j_j
j_j's picture
Offline
Last seen: 2 years 6 months ago
Joined: Mar 13 2009 - 4:22pm
Re: A very interesting article in Audio Xpress


Quote:
jj...you mentioned gold oxide.

Uh, aluminium oxide, etc, but gold? I don't think so...

KBK
KBK's picture
Offline
Last seen: Never ago
Joined: Sep 30 2007 - 12:30pm
Re: A very interesting article in Audio Xpress

That's my fault, the oxidizing gold thing. I never shoulda mentioned it -confuses the issue.

j_j
j_j's picture
Offline
Last seen: 2 years 6 months ago
Joined: Mar 13 2009 - 4:22pm
Re: A very interesting article in Audio Xpress


Quote:
I'd like to read Ed's article too.

November 2009 Audio Xpress.

jneutron
jneutron's picture
Offline
Last seen: Never ago
Joined: Sep 16 2009 - 12:34pm
Re: A very interesting article in Audio Xpress

Ah, I was not correct in attribution of statement. Sorry.

You did mention this: "" It will grow a surface layer, just like most other metals.
Some oxide, maybe some nitride, some Ag NOx ... Not much, but if it managed to obscure the metal-metal contact you can measure it.""

I thought you were saying gold oxide...but I guess you were talking about any oxides...and yes, I can see bright gold having extra stuff on the surface.

Cheers, John

j_j
j_j's picture
Offline
Last seen: 2 years 6 months ago
Joined: Mar 13 2009 - 4:22pm
Re: A very interesting article in Audio Xpress


Quote:
Ah, I was not correct in attribution of statement. Sorry.

You did mention this: "" It will grow a surface layer, just like most other metals.
Some oxide, maybe some nitride, some Ag NOx ... Not much, but if it managed to obscure the metal-metal contact you can measure it.""

I thought you were saying gold oxide...but I guess you were talking about any oxides...and yes, I can see bright gold having extra stuff on the surface.

Cheers, John

Ahh, it will grow some stuff on the surface, but it's not a hard, nonconductive layer, like say aluminium oxide, which makes a pretty bad semiconductor if you're not careful. (by bad I mean both not useful and a semiconductor)

commsysman
commsysman's picture
Offline
Last seen: 3 days 16 hours ago
Joined: Apr 4 2006 - 11:33am
The tale of the Gold-Plated Turd...

I can't believe this; 10 pages of bullshit about NOTHING!!!!! Everyone here is so busy talking about how to tweak a sow's ear, that they have forgotten that it is still a sow's ear! Sure; let's gold-plate that turd and see if it tastes like a truffle!

RCA connectors, and the unbalanced circuitry that goes with them, is such a nightmare and botch from an engineering point of view that I have nothing to do with them; they have NO place whatsoever in anything that pretends to be "high-end" equipment.

When the high-end industry gets its head out of its collective ass and totally abandons unbalanced connections and goes exclusively to balanced connections, all of this bullshit about exotic cables, gold, silver, pootonium and tweaky connections will be past history.

Trying to use unbalanced connections in high-end equipment is like using $20 Pep Boys tires on a Ferrari; it is idiotic!!!

jneutron
jneutron's picture
Offline
Last seen: Never ago
Joined: Sep 16 2009 - 12:34pm
hmmm

It is possible to achieve good results with unbalanced. It does require care, not all engineers can do it, and even fewer laymen.

Unbalanced has it's share of issues as well, it is not the end-all. Ground loops do affect it as well.

Quality of connection is of concern for both.

Cheers, John

KBK
KBK's picture
Offline
Last seen: Never ago
Joined: Sep 30 2007 - 12:30pm
Re: The tale of the Gold-Plated Turd...

Never forget that the idea of balanced connectors is based on the idea of audio signal perfection, and that the two amplifiers that are sending and the two receiving buffer amps are also idealized and somehow perfect ..and that the the cable is somehow a physical and theoretically realized act of utter transmission perfection..and all these things theoretically add up to a signal that is handled to utter perfection.

The truth is that all of these aspects are not perfect and thus create distortion, specifically in the transient domain, and with the extra circuity involved there cannot help but be a false detail and transient emphasis as this is where the bulk of distortions will occur. So we get the theoretical increase in S/N of 6db, and we get the false accentuation of cues. And we somehow, most times, confuse the accentuated cues with the noise floor quality increase. If you consciously listen for it (these given distortions) while understanding this point, then it can finally sink in that balanced can have it's weakness too. Complete, absolute, total, utter mechanistic and physical mirrored symmetry in the circuitry layout is one of the big things that needs be done in a balanced active signal handling scheme in order for it to perform as best it can. No detail can be escaped. This is rarely done. You have to do transient domain analysis and matching of the pathways and components and match them --together, at each individual step and then as a whole. Then balanced can show it's best. Then you just have the problem of twice as much stuff for the signal to pas through as a remainder to color the sonics - before you can reach for the carrot of 6db increase in S/N.

Transformer interfaces help tremendously with the handling of signal (with respects of -ve and +ve signal matching) at either end but good transformers cost real coin and some don't like the sound it produces.

Unbalanced, on the other hand, has not these three 'should be damned obvious' issues. It has it's own issues but it certainly does not suffer from those.

So no, unbalanced cabling is not trash and balanced is not god's gift. Both have their weaknesses and both have their strengths.

Some of gear that is perceived to be the best sounding in the world is built with either given signal handling interface type.

The last time I heard of anyone doing this (balanced) correctly to the level required, was John Curl's Blowtorch Preamp. IIRC, only 20 examples were made.

commsysman
commsysman's picture
Offline
Last seen: 3 days 16 hours ago
Joined: Apr 4 2006 - 11:33am
Re: hmmm

It IS possible to achieve good results some of the time with unbalanced connections; it is probable that most of the time, you will get something less than excellent results. This has been my personal experience.

One gets excellent results EVERY SINGLE TIME with balanced circuitry and cables, with no tweaking, no exotic cables, and no exceptions. Over 30 years, that has been my unvarying experience.

That is why every connection in a recording studio is balanced; professional audio engineers cannot and will not sit around trying to figure out which damn cable sounds best on every single one of their 30 or 40 connections; they know that balanced cables invariably give them perfect results unless there is a GROSSLY bad connection somewhere; a rare event.

It is stupid, in my opinion, to screw around with something that is inherently flawed in its concept and design to try desperately to get it working...when you can use something that is essentially flawless in its concept and design instead.

I think that the flailing about in the previous 10 pages proves my point as well as anything possibly can. Everyone is trying so hard to make unbalanced better, because they KNOW it is seriously flawed and variable in its results.

There IS no debate about how to make balanced cables better; the ordinary inexpensive balanced cable works perfectly every single time...duhhhhh. Wake up!

jneutron
jneutron's picture
Offline
Last seen: Never ago
Joined: Sep 16 2009 - 12:34pm
Re: hmmm

Balanced does not guarantee excellence. Balanced is a methodology for the selective removal of common mode error signals. Many professionals still have to devote resources to eliminating ground loop problems.

Google pin 1 problems.
Google DI boxes.
Google the IEEE-std for measurement of ground loop susceptibility, testing, and characterization.

Concur that most pro's do not worry about 6 nines cables and such. But they do very well concern themselves with the surface integrity of and metallurgy of contacts used in the studio and on the road. Gas tight connections are typically not, contact surfaces are old, most surfaces oxidize.

As for the choice between balanced and unbalanced for the home consumer, most do not have that luxury.

Cheers, John

commsysman
commsysman's picture
Offline
Last seen: 3 days 16 hours ago
Joined: Apr 4 2006 - 11:33am
Re: hmmm

Balanced DOES guarantee excellence insofar as its actual design function is concerned; obviously there can be no guarantee of excellence in a complete system because of perfect connections between equipment.

What you say about ground loops is true; it is also totally irrelevant to the discussion at hand.

Ground loops have nothing to do with balanced audio connections; they occur when equipment is not connected properly to common AC line grounds, or some internal chassis/circuit ground connection becomes defective.

jneutron
jneutron's picture
Offline
Last seen: Never ago
Joined: Sep 16 2009 - 12:34pm
Re: hmmm

Actually, most do not know why balanced is flawed.

Why not explain to them why this is so?

As for balanced cables, there should be a debate on them as well. Twisted pair cables in a sheath have only an integrated common centroid, and neither conductor has a common centroid with the shield at any frequency below a meg. This of course, causes aging issues for any balanced cable, as an older cable inhibits strand jumping, further compromising the low frequency centroid positioning.

Cheers, John

ps..would it be possible to tone the attitude a bit? Thank you.

jneutron
jneutron's picture
Offline
Last seen: Never ago
Joined: Sep 16 2009 - 12:34pm
Re: hmmm

As I said, look up pin 1. Look up DI boxes.

Ask questions if you do not understand. Glib and incorrect comments do not help.

Cheers, John

Pages

  • X
    Enter your Stereophile.com username.
    Enter the password that accompanies your username.
    Loading