Silver plated OFC, does it increase a cable's capacitance?
Aug 27, 2014 at 1:04 PM Thread Starter

#### SharpEars

I read somewhere that having a silver plated oxygen free copper cable increase's the cable's capacitance due to the silver/copper interface. Is there any truth to this and if so, how strong is the effect in relation to the normal small amount of capacitance found in cable pairs?

Aug 28, 2014 at 8:29 AM
If there is (and I don't feel like looking it up) the difference is less than making the cable a few inches longer.

Aug 28, 2014 at 9:15 AM
This is more of a question of whether the whole notion is BS or not.

To make a capacitor, a dielectric is needed. Where is the dielectric in the silver plated copper arrangement, since the barrier between them is conductive.

Aug 28, 2014 at 5:59 PM
All things being equal, i.e. size, geometry and dielectric materials, a cable made of silver plated copper wire won't have any more capacitance than the same cable made using unplated copper wire.

se

Aug 28, 2014 at 8:20 PM
I'm no plating expert, but I do like to test the experts once in a while.

I would think (and we are talking at an atomic scale here so it would make nil difference in a measured result) that there would be gaps, or open areas between where the physical layer of silver ends and the copper core begins.  In a solid you have atoms that form a rigid structure by aligning their bonds in a very tight array.  I would assume the molecules of silver being heavier, therefore larger, would not fill in the spaces along the top of the copper core as well as another layer of copper would.

In that regard, your insulating material causing a higher capacitance would be whatever fills that void (atmosphere?)

I think I have been at work to long...

Aug 29, 2014 at 12:17 AM
To better understand this, you need to understand two things. First that capacitance is an electric field effect. Second that electric fields do not penetrate the surface of a conductor. So basically capacitance is a surface effect. So it doesn't matter whether or not you have a copper conductor covered by a silver conductor. What matters is the external surface area of the conductors, the space between them, and the permittivity of the dielectric between them.

se

Aug 29, 2014 at 10:46 AM
I have a degree in electronics engineering and work for, let's say "a large semiconductor manufacturer".  I understand the capacitance measurement and how it works.

I was just saying, more as a thought experiment than anything, that in theory there would be, again at the atomic level, microscopic "gaps" between the silver and copper due to them not being the same size molecules.  These "gaps" would provide your external surface area between conductors, and whatever filled these voids would be your insulating material between the two.

Again, I know that this would make so little of a difference that it wouldn't be measured, but in my head, this makes sense.  Then again, a lot of things work in theory that never really pan out in practice...

Aug 29, 2014 at 12:29 PM
I was just saying, more as a thought experiment than anything, that in theory there would be, again at the atomic level, microscopic "gaps" between the silver and copper due to them not being the same size molecules.  These "gaps" would provide your external surface area between conductors, and whatever filled these voids would be your insulating material between the two.

And how exactly do you achieve any voltage potential between those "gaps"? When you're talking about the gaps between copper and silver, you're talking about a single conductor. How do you manage to have capacitance within a single conductor?

se

Aug 29, 2014 at 2:01 PM
Even if considered 2 conductors, there will be 0 resistance between them so I guess it can't even be considered 2 conductors.
I've heard things like there could be a diode type of effect at very high frequencies but it's way beyond what could theoretically affect audio. For me, plating does change the sound but there is no way I could ever prove it in measurements.

Aug 29, 2014 at 2:19 PM
And how exactly do you achieve any voltage potential between those "gaps"? When you're talking about the gaps between copper and silver, you're talking about a single conductor. How do you manage to have capacitance within a single conductor?

se

Silver and copper can't have exactly the same electrical properties, or there would be no reason to use silver other than its appearance.

I got nothin'.

Sep 8, 2014 at 1:40 PM
I read somewhere that having a silver plated oxygen free copper cable increase's the cable's capacitance due to the silver/copper interface. Is there any truth to this and if so, how strong is the effect in relation to the normal small amount of capacitance found in cable pairs?

Your typical DIY twisted pair copper cable is just a few pF per conductor, and some commercially-built enameled copper cables may go up to a few nF.  Then I check my cheap, hardly used SPC cables after reading your post and find that they measure in the tens of uF per conductor, that's a million times more capacitance (1000pF = 1nF, 1000nF = 1uF).  Maybe it is true after all.  I didn't know that.  Still, this is cheap SPC, Maybe custom spc like what Toxic Cables sells might be better?

In any event, I wouldn't worry about capacitance and inductance in a cable, if I were you, unless each of those aspects measures in the hundreds or thousands of uF/mH, then that would mean that the cable is damaged and you would then be getting channel imbalance/coloration to some noticeable degree.