Metals for prefab and DIY cables

[Will_B]

I’m looking to start making my own cables. Part of this is finding the right cables, prefabricated connectors and metal choice.

As we all know gold plating is the gold standard (owning up to the pun) and there is a general consensus that like-for-like pairings are the most desirable, e.g. gold plated contacts to gold-plated receptacles. The base metal or substrate for gold plating is almost always nickel which is not a good electrical conductor.

If one spends a lot of money on copper and silver cables, is not the weakest link in the electrical chain nickel substrate under the gold plated connectors? Or is the thickness of the nickel substrate negligible so as not to affect the other high quality parts of the cable?

I wonder about gold plating in the same respect. Is it that the plating is so thin, only some microns in thickness, that it will not reduce the overall conductivity of copper and silver cables?

Because if nickel and gold do in fact interfere with the electrical conductivity of the cables then we can all stop spending money on expensive cables.

 

[howard416]

Like, you're worried that the gold plating is going to wear through? Or you're just worried about the (negligible) added resistance?

 

[DVDdoug]

The advantage of gold plating is that it doesn't corrode, not lower resistance. But it's VERY thin plating and I assume it easily wears-off of the contact areas and maybe becomes useless after a few connects & disconnects....

Nickle is probably used for its "springiness" to maintain contact pressure. The resistance/conductivity depends on the cross sectional area and the length (and the material). So a short-fat conductor of less-conductive metal inside a connector doesn't add much resistance. The smallish contact area between mating contacts is probably the "weak link".

In any case, resistance/conductivity isn't much of an issue in audio applications except with speakers where we want low resistance relative to the 4 or 8-Ohm speaker and there's nothing tricky about getting a low-resistance connection.

 

[howard416]

Gold Plating Thickness of Connectors - Advanced Plating Tech Blog

Gold plating thickness of connectors can vary. A common application would be gold plated battery contacts for personal electronic devices.

advancedplatingtech.com

 

[somebodyelse]

we can all stop spending money on expensive cables.

I'd go with that one. In most normal domestic cases there won't be a measurable difference between a throwaway cable bundled with a cheap device and an expensive one made with exotic materials, as has been shown in measurements here and elsewhere. In specific situations particular aspects of the cable construction will make a measurable difference, say the extra rejection of starquad over twisted pair if you're running a mic cable close to a transformer, or the low resistance of a heavy braided shield reducing the noise voltage from leakage currents in single ended interconnects. In those cases you need to know the problem you're addressing to pick the correct construction though - in other situations the extra capacitance of the starquad may make it a worse choice than the twisted pair. I'm not aware of any tests showing a significant audible or measurable difference between different connector plating materials. Some will probably argue silver or rhodium are better than gold though.

 

[Blumlein 88]

Some cables use rhodium plating because it is tougher.

 

[mansr]

Some cables use rhodium plating because it is tougher.

But mainly because it sounds more exotic.

 

[FrantzM]

I smell a ... troll... My apologies if I overeacted,,

 

[Blumlein 88]

But mainly because it sounds more exotic.

Well there is that too. I had a set of speaker cables with Rhodium and while you could crank down hard and not leave a mark, and they always look shiny and new for years, they also seemed a bit slick. They would sometimes slip out easier over time than seems the case with gold plated connectors.

 

[Skeptischism]

the reason for the nickel is gold does not direct plate over copper very well, the copper will often diffuse/migrate into the gold, making it pretty useless for its intended purpose.