Lets talk cables

[tomelex]

Some folks on this forum might want to read measurements of different cables affecting sound. They do, and like anything in audio, especially in the boutique world or the garage con artists, if you screw something up enough you will get results.... document page 39 is where it starts for those who need to learn more about cables. The contrary to the above underlined is if you perfect something enough it is no longer audibly improved....

http://www.biline.ca/audio_critic/mags/The_Audio_Critic_16_r.pdf

 

[Fitzcaraldo215]

Some folks on this forum might want to read measurements of different cables affecting sound. They do, and like anything in audio, especially in the boutique world or the garage con artists, if you screw something up enough you will get results.... document page 39 is where it starts for those who need to learn more about cables. The contrary to the above underlined is if you perfect something enough it is no longer audibly improved....

http://www.biline.ca/audio_critic/mags/The_Audio_Critic_16_r.pdf

Thank you. Since reading that, as I did way back when, I have been a believer in short, hi gauge (low R) speaker cables preferably also with low inductance (L), and, of course, no exotic metals or winding geometry, or flat ribbons, or built-in networks, etc. I cannot measure or model myself, but I think that has kept me out of trouble, and it has saved me a bundle of otherwise wasted money. Not hard to do, as long as the manufacturer provides basic LRC electrical specs. If he doesn't, look elsewhere.

For interconnects, short is also good, but if you must go long, balanced XLR is the way to do it, preferably with low capacitance (C), as in pro mic cable, but not "audiophile" stuff.

Of course, tube gear throws a monkey wrench into all this with its own special loading characteristics and consequently larger response deviations, making cables a clumsy, inflexible choice of effectively tone controls with that gear.

 

[SIY]

Of course, tube gear throws a monkey wrench into all this with its own special loading characteristics and consequently larger response deviations, making cables a clumsy, inflexible choice of effectively tone controls with that gear.

Not "tube gear" but "poorly designed tube gear." Morgan Jones uses the expression "designed, not engineered," and I think that's quite apt. There's solid state gear equally poorly designed, but of course in the audiophile's world, it's "exceptionally revealing of cable differences."

 

[palamudin]

Not "tube gear" but "poorly designed tube gear." Morgan Jones uses the expression "designed, not engineered," and I think that's quite apt. There's solid state gear equally poorly designed, but of course in the audiophile's world, it's "exceptionally revealing of cable differences."

Dont forget the veil lifting.

 

[SIY]

God no, I would never forget the veil-lifting. That's the best part!

 

[Wombat]

Dont forget the veil lifting.

At $5000 I could forget it, however, I like the all-in-one concept.

Caution: If you let the video run-on you may get an unsettling surprise.

 

[Jakob1863]

I'm sure there was a point in there, desperately trying to get out, but finding it would take more effort than I'm willing to put in.

In the meantime, perfectly ordinary wires work perfectly well for transport of low frequency signals from point A to point B. After 30+ years of the exotic wire racket, there is zero controlled listening evidence to the contrary, so it's a pretty safe assumption at this point that no such evidence will be forthcoming.

Cue the next wall of words.

The somewhat surprising fact remains that the same member is able to point to real triboelectic related effects but claims now that "perfectly ordinary wires work perfectly" , so the conclusion is that no "ordinary cable" can have noticeable triboelectric effects?

Also the same member pointed to the fact, that the specification of input capacitance (of MM phono stages) is rare and often wrong, and therefore cables with low capacitance are needed as otherwise the best fit was already exceded by just one meter of cable. but claims now that "perfectly ordinary wires work perfectly" .
So additionally the conclusion is that "ordinary cable" is always sufficiently low in capacitance?

Both conclusions are obviously incorrect, so why posting the "....work perfectly..." line?

Btw, "there is zero controlled listening evidence ot the contrary" isn´t correct either, but that is another issue.

We (at least i) was talking about basic engineering stuff but it seems that the obsession with "fancy" or "audiophoolery" or "overpriced" cables prevents members from sticking to this "ordinary" stuff.

 

[SIY]

Since the triboelectric issues occur when you don't use perfectly ordinary wire, my point is demonstrated. Ditto low cap cable- you can buy that off the shelf from Digikey, Mouser, and other ordinary sources. No need for anything exotic or expensive or having fairy tales attached to it. These are perfectly ordinary wires.

You're working hard to make an easy issue difficult.

 

[Jakob1863]

Since the triboelectric issues occur when you don't use perfectly ordinary wire, my point is demonstrated.

Sorry, but you only provided you personal experience with one cable - non ordinary because of the silver/teflon combination. The conclusion that "only" non ordinary suffers from this effect is a non sequitur and from the table i posted it can be seen that an ordinary using pvc in no way ensures that no triboelectric issues occur.

Ditto low cap cable- you can buy that off the shelf from Digikey, Mouser, and other ordinary sources. No need for anything exotic or expensive or having fairy tales attached to it. These are perfectly ordinary wires.

As i´ve said you seem to be obsessed with "exotic" or "expensive" or "fairy tales" ......

Chances to find a cable with sufficiently low capacitance are much higher if you explicitely look for them; looking for "ordinary cables" will most likely not help.

You're working hard to make an easy issue difficult.

Although i only briefly mentioned that shielded, twisted pair might often be a better choice than other constructions for phone applications.
Is looking for qn "ordinary" cable really the best way to ensure that a consumer will get a shielded twisted pair (shield only connected at one side) with a capacitance of max. 40 - 60pF / m with no triboelectric issues?

 

[DonH56]

Is there an article showing the degradation of audio performance in cables (and the rest of the system) due to triboelectric effects? Sorry if it was posted earlier and I missed it, this thread is hard to follow.

 

[SIY]

You do understand that "ordinary" is not the same as "universal," right? Something ordinary suited for application A may not be suited for application B, yet is still ordinary. E.g., if I use a 3 meter RCA interconnect for amp to loudspeakers, it won't work well. Or a high capacitance cable where I need low capacitance, ditto. And if I avoid exotic stuff like Teflon-silver, I will not have much to worry about regarding triboelectric noise.

Ordinary. Simple. Common sense.

And apparently anathema.

 

[SIY]

Is there an article showing the degradation of audio performance in cables (and the rest of the system) due to triboelectric effects? Sorry if it was posted earlier and I missed it, this thread is hard to follow.

No, it was me relating a one-off personal experience with a niche application (high impedance, low voltage). Totally avoidable by using more ordinary wire- which is what I did (copper/pvc) and it cured the issue.

 

[DonH56]

OK, thank you sir. I could relate a number of times it has been a problem, along with various other cable issues, none of which are applicable to audio systems so was curious.

The biggest problems with interconnects I have seen (YMMV!) are poor shields, noise coupling in high-noise environments (usually solved by going to shielded XLR or double-shielded RCA cables with the outer shield isolated from the inner and lifted at one end), and ground loops. Microphonics in cables was one of those things raised decades ago and subsequently proven to be readily measurable but negligible in practice. I wish I could find my box of old test results from my days "in the biz" as I did try a few things way back then. Nothing was audible but it was fun do. In addition to the usual "flex the cable whilst listening" experiments I remember suspending (hanging) a loop of cable in a loop and blasting it with pink noise and swept (single-tone) signals. With hi-z source and load you could actually see the effects, but with a low-Z source it essentially went away.

No proof at this point, though you can find plenty in the RF world dealing with uV-fV signals, just memories and rambling from an old fart. - Don

 

[SIY]

Yeah, like I said, a one-off which taught me a lesson ("Never fall for audiophile myths about materials"). My "testing" was no more than brushing it against the table while having the volume turned up.

Well, come to think of it, a two-off. When I was testing some ultra-low-noise mikes from PCB Piezotronics (by low noise, I mean <5dB SPL) that used CCS rather than the usual audio balanced/phantom voltage source, just for fun I tried a PTFE-silver cable. The non-random noise increased a bit, indicating I was picking up vibration. Going back to a standard coax cable dropped the noise.

https://www.pcb.com/Contentstore/Mk...eprints/AudioXpress-Microphone-Evaluation.pdf

See page 4 for the anecdote.

 

[Jakob1863]

<snip>. Totally avoidable by using more ordinary wire- which is what I did (copper/pvc) and it cured the issue.

And that illustrates imo perfectly my point; "ordinary" = "copper/pvc" = "no triboelectric issue" as easy as incorrect.

You had bad luck with an "not so ordinary" combination of silver/teflon -totally avoidable by better (and/or more careful cable construction/manufacturing when using silver/teflon) and you were lucky with an "ordinary" combination (copper/pvc) but that was just luck but not warranted by the "ordinary" materials mix.
Why? Because in the "triboelectricity list" copper is at the same position as silver and pvc isn´t really that much higher positioned than teflon.
And from the numbers i´ve posted you can conclude that it is as easy to manufacture a cable with triboelectric issues from a copper/pvc material combination as it is from a silver/teflon combination.

So if you want a cable without (or low) triboelectric issues you have to search for a cable with low triboelectricity. Searching for "ordinary" cables made from the "ordinary" materials "copper/pvc" will not ensure that you get a cable with low triboelectricity.

 

[SIY]

No searching needed. Substituting an ordinary cable fixed the problem- twice.

This really isn't that difficult, no matter how hard you try to make it so.

 

[DonH56]

Yeah, like I said, a one-off which taught me a lesson ("Never fall for audiophile myths about materials"). My "testing" was no more than brushing it against the table while having the volume turned up.

Well, come to think of it, a two-off. When I was testing some ultra-low-noise mikes from PCB Piezotronics (by low noise, I mean <5dB SPL) that used CCS rather than the usual audio balanced/phantom voltage source, just for fun I tried a PTFE-silver cable. The non-random noise increased a bit, indicating I was picking up vibration. Going back to a standard coax cable dropped the noise.

https://www.pcb.com/Contentstore/Mk...eprints/AudioXpress-Microphone-Evaluation.pdf

See page 4 for the anecdote.

Got it, thank you. I suspect it was something other than triboelectricity but obviously I was not there and have no measurements to show either way.

From the article: "As an aside, I should mention that I tried a very thin cable using PTFE dielectric with the idea that increased flexibility should result in lower vibration pickup. Unfortunately, this turned out poorly, but I now know a novel way to make a vibration sensor. I don’t know what was to blame, the increased triboelectric potential or the lowered wire-to-shield rigidity of PTFE, but there was no question that the conventional coaxial cable performed better."

Flexible cables are known to be more vibration-sensitive than rigid cables, and "very thin" likely means poorer shielding and higher capacitance (and inductance). I suspect that, or perhaps poorer shielding with the smaller flexible cable, led to the poorer performance. Again my experience with specialty audio cables is dated and limited but in the RF world the best cables for performance are big and rigid. Unfortunately such cables are very unwieldy and limited to fairly specific applications. Solid PTFE can exhibit other issues with extremely low-level signals including higher noise and such but not my area of expertise...

Piezoelectric mics look capacitive IIRC and I suspect are more sensitive to impedance and capacitive modulation than more conventional mics. Again, not my area of expertise, take with block of salt.

 

[SIY]

All true, and I appreciate your insight here.

I should note that despite the company name, the PCB mikes aren't piezo, they are self-polarized condensers. Still, the CCS versions would have a high output impedance, and that's where I ran into the increased noise with the "fancy" cable.

 

[Jakob1863]

No searching needed. Substituting an ordinary cable fixed the problem- twice.

This really isn't that difficult, no matter how hard you try to make it so.

Even twice, well then, that´s unbeatable in science.

Who said it is difficult?
It´s usually just more promising to look/search for the right thing.

 

[Wombat]

Is there an article showing the degradation of audio performance in cables (and the rest of the system) due to triboelectric effects? Sorry if it was posted earlier and I missed it, this thread is hard to follow.

I thought the triboelectric issue in audio was mainly pertinent in low signal transmission through cable into high impedance/gain circuits and the cable was likely subject to mechanical disturbance(moved), as in microphone use. Why it is even discussed for home HiFi systems is beyond me.