Non issue for audio. Skin effect depth for 100khz is 200 micro meters. Really oxidized silver is in the 100's of nano meters.
Calculator for skin effect depth
Understanding how silver objects tarnish - Canada.ca
I dont know that skin depth of silver oxide does not affect signal in some way compared to no oxide. Many people have removed oxide and tarnish from wire. part leads and connectors to audible affect.
-RM
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My experience and opinion also.
Hi Scott.
From my investigations I find that wire/cable can be directional, iow causing the system to sound different according to directions.
What is this difference ?.....I did already answered this but I will elaborate, the difference is not in the forefront high level sounds so much as in the low level stuff....ambience, decays, perceived noise floor.
When listening to music (ie not test signals) the difference is in the how this low level information is affected/effected by signal excited/driven excess (current) noise which has different 'character' according to interconnect direction.
With the wav file/source/preamp configured to output 2ch mono, the transient triggered decaying excess noise sounds 'in phase' or 'out of phase' wrt the music according to interconnect direction.
Swapping direction of one interconnect causes low level noise at center to 'broaden' indicating reduction in ch/ch coherency of the signal excited excess noise.
The 'depth' of this low level excess noise increases/broadens also indicating change in ch/ch coherency of the decay/time characteristic of the produced excess noise.
I have a recording of the noise produced by a faulty/leaky/noisy input diff pair transistor....lots of spiking and bursts of varying level erratic noises, this it seems is an unusually useful test signal.
IOW direction swapping both IC's causes the excess noise to sound somewhat like program in correct vs inverted absolute polarity....one direction 'plays nice' with the program content, opposing direction does not.
Reversing one only IC causes sound somewhat like inverted absolute polarity of one channel.
Note that the effect is to do with excess noise, so an 'ideal' signal chain will not reveal/suffer these affects so 'badly' as 'mid-fi' gear.
Now that you know what to listen for you may be able to hear the affects/effects of swapping cable directions around.
Your 'industrial noise' recordings might be a useful signal, I have not tried (it hurts my ears lol).
Dan.
contact r is increased by oxide build up on contacts.
Oxides between conductors in physical contact with each other (connectors) have a voltage needed to break thru the thin insulator/oxide. Only use hermetically sealed contacts where possible. Removable cable connections must be air tight at the contact point.
-RM
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If I remember correctly, silver oxide is a pretty good conductor still, but silver sulfide is not. I'd still want my contacts clean.
I haven't ever seen directionality indicated on expensive air dielectric RF cables for VNA use up to 40GHz...
https://www.fairviewmicrowave.com/rf-products/ruggedized-vna-cables.html
I haven't ever seen directionality indicated on expensive air dielectric RF cables for VNA use up to 40GHz...
https://www.fairviewmicrowave.com/rf-products/ruggedized-vna-cables.html
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Easy to hear also means easy to measure, looking at the difference. How come it never happened? At least I'm not aware of any measurements that isolate the sonic difference with a music signal. Showing minor discontinuities of characteristic impedance at RF freqs and such buys us nothing, show us the real difference with music signals!
Dan, you're saying that a cable always adds a signal-correlated "noise" to the signal and when swapping direction you get a similar but slightly differently flavoured "noise" from this, still strongly signal-correlated, so when used in dual mono the phantom center of the low-level correlated noise falls apart?
If so, this would be relatively easy to measure.
If so, this would be relatively easy to measure.
You're on to it, although I would not say that the cable causes noise so much as causing change in system excess noise according to cable direction, somehow.
Give it a go and see if you can hear anything interesting.
I need to get a few connectors and then I will run some testing and see what I can measure.
Dan.
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Seems to me that maybe Dan is hearing connector issues rather than wire issues, if anything. Maybe thermocouples, oxide noise source, whatever. I know it seems very hard to imagine a mechanism from an engineering perspective, but I have had some conversation with Dan by PM and so on including sending him some files to differentiate by ear. My impression is that he has extraordinarily good hearing for small aberrations, but whether they are physical in every case might need blind testing for the engineers to be as sure as Dan is. He does seem willing to be tested if only there were someone to set it up and proctor. In the meantime if the more extreme claims are too far out for now we might want to focus on some other claim that might be easier to verify or investigate. Also, it might be helpful if Ed Simon would be willing to say more about his findings with connectors, and if that might account for what Dan describes. Still, I would have to say some of the claims boggle the engineering mind, and for those blind testing would seem the most needful initial investigational effort.
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Sometimes it drives me wildYouTube
Ian always gets them going, I was at the last Minor Threat show in Boston.
Don't forget to do a reality check, the physics and medical diagnostics fields are full of signals orders of magnitude lower than what we are interested in here. None of these effects are observed.
Thermal effects can be observed but as I pointed out to Ed the problem becomes a multi-physics one and clipping components in and out of a sky-wired breadboard does not cut it. Note connectors below.
Attachments
Stabilent 22 for low level signals.
Lowers distortion by contact enhancement without shorting adjacent contacts.
Upper curve is pc board connected after 31 days of free air exposure.
Middle curve is contacts when new.
Bottom curve is exposed contacts treated with Stabilent 22
Lowers distortion by contact enhancement without shorting adjacent contacts.
Upper curve is pc board connected after 31 days of free air exposure.
Middle curve is contacts when new.
Bottom curve is exposed contacts treated with Stabilent 22
Attachments
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Yes, oxides again. and double the numbers for a cable with 2 connectors... plug and jack. Plugging and unplugging just varies the contact R. cleaning them and applying stab 22 to keep oxides from forming is best way .... So maybe not directional cable but 'different' when changed.
Hard gold plating is used to prevent oxidation of the base metal. But keeping pollutants et al from them requires cleaning. And a plug-jack that makes air tight connection at the contact area. Many RCA style do not do this.
THx-RNMarsh
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Yes, I have considered the above, but I think not.
I am aware of Ed Simons paper regarding connector issues and have cleaned/treated all connectors.
I agree that there is question of mechanism from engineering perspective which is however dealing with 'idealised' conductors and dielectrics.......are we actually certain that neither dielectrics or conductors can have directive properties embedded by fabrication methods ??.
There are 'crystal boundaries theories' or 'micro diodes theories' purporting to be the explanation for wire directivity.....I have never seen proofs but I have performed tests that clearly showed directional property in the case of bare copper wire.
What happens during dielectric extrusion around wires....are there 'frozen in' stresses that cause directional dielectric properties ?.
My 'extraordinarily good hearing for small aberrations' is borne of my test signal methodology which allows instantaneous or very nearly instantaneous switching on the fly, and high repetition.....long term memory is not required.
Getting to the bottom of this wire directivity property is good enough for me for now.
Once proven, blind testing would serve to gauge the 'audibility' of such directivity for subsets of systems and subjects.
The PB system I am using is fully floating so no earth paths alternate to cable shields are present.
I welcome Ed's input.
Sure, whilst they go against what we have all been taught that does not make them untrue.
I have subjectively experimented/investigated and confirmed wire and cable directivity too many times to dismiss the subject.
One thing to be aware of here that this 'anomaly' is about direction of energy flow wrt cable direction causing changes in downstream noise production.....this is not the same as signal half wave direction.
Dan.
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I have considered all of the above already and agree contact issues could be an explanation.
However the tight center image is present with both cables in normal or reversed direction, and the center image falls apart when one cable only is reversed and regardless of which one.
I think this precludes contact issues in this case.
Dan.
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...or listened for.
Audio is baseband signal that we are extraordinarily sensitive to, sensors and displays are not quite the same.
Thermal effects are not significant here I think.
Dan.
Conditions on these plots are totally unspecified. For all I know they are forcing enough current through a contact to generate the mV. Also there is no instrument with a flat line THD+noise that extends to 0. The numbers also imply nV or sub-nV harmonics.
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