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[Sahib]

Dan,

Many thanks for the explanation. I was merely pointing out the conducting values of the silver and copper. However, I again completely agree with you that auido cable issue is greatly hyped and in most cases it turns into emperor's cloths.

Regards,
Cemal

[danlavry]

I've found that certain 110Ω digital audio cables can be microphonic in certain audio applications (load-impedance can surpress this effect to a greater or lesser extent) but generally, copper (and lots of it) is good, becoming of increasing importance where the load impedance is lower. Capacitance is bad, becoming of increasing importance where the source impedance is higher. Inductance is bad, becoming of increasing importance where the load impedance is lower.

I keep coming back to the same point: Optimizing the cable is best done when knowing the application. After talking about cable capacitance NOT being a problem for many audio applications (low impedance driver and high impedance load) I see it being interpreted as “go for low capacitance” or as “use digital audio cables”.

I think people prefer to not be bothered with having to think learn and think about details. It unfortunate, because there is no such thing as “one shoe fits all”, nor is there “one cable fits all”.

Your comment about microphonics is a good example. A cable carrying DC signal can respond electrically to mechanical disturbance (such as tapping or moving). The mechanism is similar to the operation of a condenser mic – parallel pieces of metal (2 wires or a wire and shielded) are in fact a capacitor. A DC charge on a cable between the conductors will generate an ac (signal) voltage when one changes the distance between the conductors, such as when tapping on the cable.

Normally, such microphonics is more offensive when the signal level is low and will be amplified (such as cables for microphone applications). It is wise to avoid DC on cables but in some cases such as condenser mics there is a lot of DC (48V), thus no escape from DC.  So a more “solid” cable may be of benefit for high DC voltage case. Again, one can approach or supplement a solution for DC micophonics by protecting the cables from mechanical motion.  

The other factors affecting the DC voltage microphonics are the parallel combination of source resistance and load resistance. If we have low impedance (resistance) than the ac voltage due to mechanical motion (microphonics) will be lower amplitude. But it is best to have a low source resistance, and a high load resistance. Adding additional load is not very effective, because the discharge path for the audio signal is almost completely determined by the much lower impedance at the source side (often in the 75 Ohms range), unless you are ready to go to very low resistance load (very bad idea in general).

There are other factors impacting DC voltage microphonics, mostly mechanical. Generally speaking you want a cable with a greater distance between the conductors, and the material to be of low dielectric constant. These are the same factors that make for low capacitance cable. Low capacitance tends to yield low “change in capacitance” due to mechanical causes. We want to minimize the change in capacitance. And of course, as always, the longer the cable, the more charge thus the more microphonics…

   
Regards
Dan Lavry

[fishtank]

Sahib wrote on Mon, 13 December 2004 20:29

I completely agree on the amount of hype that is made on cables but in terms of silver vs copper, of course silver is better as it is a better conductor than copper. Hence you do not need to see a proving formula to accept it. However, how much difference does a silver conductor make in audio frequency  and how possible it is to hear that change is another matter. But I can assure you that it would make a difference. Cemal

I was well aware of the fact that silver is a better conductor than copper.  The point I was attempting to make is that I seriously doubt there would be an audible difference between good quality copper cable and the overpriced audiophile silver stuff. Just because one person claims it *seemed* to sound better is not convincing to me. I never stated there would be NO differences in electrical properties (however slight they may be).

There is much more to microphone or line level cable performance than resistance of the conductors, not to mention the fact that a larger diameter copper conductor could have less resistance than a smaller silver one.  I would personally choose low capacitance and good shielding over conductor resistance.

[ssltech]

Absolutely.

In fact nothing is of greater influence than the nature of the boundary between source and destination, and this is the exact boundary at which the cable lives. When "Mega-brand corporation" wants to dempnstrate their "superior" cables they naturally choose source and load impedances which show their products in the best light... and I can't condemn them for that, anyone in their right mind would!

It becomes a problem when people over-simplify, and take away only a "Mega-brand good, cheap bad" distillation. Couple with this what a wise-old-owl mother of an ex Girlfriend of mine used to say: "People of no discernment cannot afford to buy cheap" and you have a simplistic reduction that some brands cannot be good, others cannot be bad.

Here's a couple of links to some of Steve Lampen's stuff, in case it helps anyone else to think for themselves!

http://www.rwonline.com/reference-room/wired-4-sound/rwf-lam pen-08.15.01.shtml

http://www.rwonline.com/reference-room/wired-4-sound/rwf-lam pen2.shtml

http://www.hpaonline.com/files/public/CoaxHistoryVideo.pdf

Keith Andrews

[Sahib]

fishtank wrote on Tue, 14 December 2004 19:01

Sahib wrote on Mon, 13 December 2004 20:29 I completely agree on the amount of hype that is made on cables but in terms of silver vs copper, of course silver is better as it is a better conductor than copper. Hence you do not need to see a proving formula to accept it. However, how much difference does a silver conductor make in audio frequency  and how possible it is to hear that change is another matter. But I can assure you that it would make a difference. Cemal I was well aware of the fact that silver is a better conductor than copper.  The point I was attempting to make is that I seriously doubt there would be an audible difference between good quality copper cable and the overpriced audiophile silver stuff. Just because one person claims it *seemed* to sound better is not convincing to me. I never stated there would be NO differences in electrical properties (however slight they may be). There is much more to microphone or line level cable performance than resistance of the conductors, not to mention the fact that a larger diameter copper conductor could have less resistance than a smaller silver one.  I would personally choose low capacitance and good shielding over conductor resistance.

I completely agree with you fishtank. I stated in my previous post that this issue is like the emperor's clothes. I am surrounded by audiophiles who pay stupid amount of money to cables. In fact I have witnessed somebody upgrading a speaker cabinet internal connections with silver wire and then turning the volume up and saying how the bass frequencies became deeper with a smile on his face. I am sure it made a difference in conducting the signal butI did not hear a damn difference sonicaly.

[PookyNMR]

My brother, having done some testing, did find a measureable difference with silver conductors.  He found increased high frequency transmition over oxygen free copper.  This was a few years ago so I don't remember his exact measurements.  I don't quite understand how this could be, but those were his results.

Nathan

[bobkatz]

ssltech wrote on Tue, 14 December 2004 13:01

I've found that certain 110? digital audio cables can be microphonic in certain audio applications (load-impedance can surpress this effect to a greater or lesser extent) but generally, copper (and lots of it) is good, becoming of increasing importance

You mean, as an analog interconnect, I'm sure. If the cable is microphonic wouldn't that imply a non-constant impedance as you move the cable around or even tap on it? Then it wouldn't make a very good digital cable, either.

If you mean microphonics when used with microphones, I can thoroughly understand, because these cables are very stiff by their very design and would pass physical shock onto the microphone. Not a good thing.

BK

[RMoore]

ssltech wrote on Tue, 14 December 2004 19:01

Me, I say buy decent cable, use good connectors (Neutrik are innovative and convenient, but Switchcraft are electrically better... trust me!)   Keith Andrews

Curious - Why are Switchcraft better electrically?
FWIW I find the Neutriks are 5 million x more convenient than having to unscrew tiny screws Switchcraft style..
Thanks in advance!
RM

[Bob Olhsson]

The classic Switchcrafts are much more rugged. Silver oxide is a better conductor than gold and in most cases the silver is lots thicker than typical gold flashing.

Everybody finds Neutriks 5 million x more convenient until the first time one fails! My friends ALL went back to Switchcraft after a brief fling with Neutriks.

[RMoore]

Yikes! OK, thanks for the info,
all the best,
Ryan

[PookyNMR]

danlavry wrote on Tue, 14 December 2004 12:00

[There are other factors impacting DC voltage microphonics, mostly mechanical. Generally speaking you want a cable with a greater distance between the conductors, and the material to be of low dielectric constant. These are the same factors that make for low capacitance cable.

Interesting that you mention the dielectric constant.  I read an article from a fellow from Gepco that mentions the importance of keeping this constant low by using some materials and avoiding others.  If I understand correctly what he was saying, the dielectric constant also plays a factor in noise rejection.

Nathan

[danlavry]

PookyNMR wrote on Sat, 18 December 2004 07:32

danlavry wrote on Tue, 14 December 2004 12:00 [There are other factors impacting DC voltage microphonics, mostly mechanical. Generally speaking you want a cable with a greater distance between the conductors, and the material to be of low dielectric constant. These are the same factors that make for low capacitance cable. Interesting that you mention the dielectric constant.  I read an article from a fellow from Gepco that mentions the importance of keeping this constant low by using some materials and avoiding others.  If I understand correctly what he was saying, the dielectric constant also plays a factor in noise rejection. Nathan

As far as I know, the dielectric constant effects only the electric field, therefor the capacitance. It does not impact the magnetic field strength. I do not see how it can impact noise. Where is that article?

Regards
Dan Lavry  

[Spaceman]

Since we're discussing cables here I just wanted to mention some mic testing research that I just completed.  You can find the complete post in the product review section here at the forums. (topic: The question everybody asks but no one answers) Read the entire thing though before you decide me to be shill!

[danlavry]

Spaceman wrote on Mon, 20 December 2004 20:59

Since we're discussing cables here I just wanted to mention some mic testing research that I just completed.  You can find the complete post in the product review section here at the forums. (topic: The question everybody asks but no one answers) Read the entire thing though before you decide me to be shill!

I appreciate the fact that it took time and that you want to share. However in this forum we try and stay technical, away from opinions based on listening, subjective remarks and specific gear recommendations.

Regards
Dan Lavry

[PookyNMR]

danlavry wrote on Mon, 20 December 2004 13:45

As far as I know, the dielectric constant effects only the electric field, therefor the capacitance. It does not impact the magnetic field strength. I do not see how it can impact noise. Where is that article? Regards Dan Lavry

Dan,

Found the article.  It is by Joseph DiBenedetto.  He said:

Along with twisting and shielding, the dielectric is an instrumental factor in the performance of the cable.  The dielectric in the cable is the insulation that coats each conductor, electrically separating the conductors from each other and the shield.  When the signal travels down the copper conductor, it will actually be ?absorbed? through the dielectric and into the shield.  This occurs to a greater effect at higher frequencies.  Typically, you should look for a dielectric with a low k constant. ?For the dielectric, you should choose a solid polyethylene, foam polyethylene or foam polypropylene compound,? Fehl explained.  ?Stay away from PVC-type compounds because the dielectric constant is higher.  The lower the dielectric constant, the lower the high-frequency attenuation.?

Apparently, I got my info mixed up with other info.  The importance of the constant had to do with high frequency attenuation.

Nathan