Nickel-plated contacts

[howard416]

I have a bunch of pretty decent balanced TRS to XLR cables. The XLR side has silver-plated contacts so I'm not worried about those (if there's any tarnishing I'm fine to just unplug-replug the connectors once in a while, though I doubt it'll be an issue). However, the TRS side has nickel-plated contacts, and I'd like to know that the nickel doesn't add any distortion, especially when connected to gold-plated TRS jacks.

Thoughts?

 

[somebodyelse]

It shouldn't be a problem unless perhaps if you're in a damp salty environment, but I don't have measurements to back it up. Gold plating is usually done over nickel anyway, so its presence isn't a problem. Gold has extra corrosion resistance, but nickel usually stays corrosion free for years unless you're in a particularly corrosive environment like somewhere humid and close to the beach. Even then it's easy to clean on a TRS, so I wouldn't worry.

 

[kyuu]

It's weird how many topics about the material properties of connectors seem to be popping up lately.

In any case, the answer is always the same: it really just does not matter. The small differences in conductivity are irrelevant when you have such a large cross-sectional area making contact. You're also dealing with very little current in cables for line-level signals. I've also never seen any substantiation that any particular material can somehow distort the signal. Finally, nickel is extremely common and almost always is underneath the gold/silver/whatever plating that is largely just there for looks.

 

[solderdude]

Nickel is a more scratch resistant conductor than gold or silver.
Just like copper, gold and silver the nickel plating has no 'sound character' despite many people claiming this'.

All these materials conduct all audio frequencies (and above and below it) with equal frequency response/resistance and don't add distortion.
Theoretically it would be best to have both contacts (so plug and socket connection materials) to be the same material.
When different materials are pressed against each other with sufficient force (which should always be the case) then different materials don't matter.
When the contact area/surface pressure is poor even the same materials won't help.

In other words there is nothing to worry about when mixing gold plated and nickel plated (or silver plated) connectors.

Nickel plated is much preferred when the connector is regularly removed/inserted (headphone connectors) simply because the material is harder and won't wear as much.
The worst material is the lovely and expensive looking gold plating. Gold is soft and the very thin layer is easily scratched/wearing when inserted now and then.

 

[pma]

Nickel is a better and above all more scratch resistant conductor than gold or silver. Just like copper, gold and silver the nickel plating has no 'sound character' despite many people claiming this'. All these materials conduct all audio frequencies (and above and below it) with equal frequency response/resistance and don't add distortion.

Are you sure?

'Influence of output relay contacts to power amplifier distortion'

Aug 18, 2025

My goal is to show how output relay contacts may worsen THD of a high power amplifier. The amplifier under test is this one:

https://pmacura.cz/DIY_250W_4ohm_amplifier.html

and the output relay under test is Finder 40.31.9.024.0000 type with AgNi contacts. It has maximum contact current of 20A and is rated at 10A ac current with resistive load. The tested parameter was THD vs. output power at 1kHz into 4ohm and 2.2ohm resistive loads. Measuring bandwidth was 45kHz.

1. Load 4 ohm

Distortion is same up to 20W/4ohm. Then we can see and effect of nonlinear contact...

• pma
• Replies: 0
• Forum: Amplifiers, Phono preamp, and Analog Audio Review

• 

 

[kyuu]

Are you sure?

'Influence of output relay contacts to power amplifier distortion'

Aug 18, 2025

My goal is to show how output relay contacts may worsen THD of a high power amplifier. The amplifier under test is this one:

https://pmacura.cz/DIY_250W_4ohm_amplifier.html

and the output relay under test is Finder 40.31.9.024.0000 type with AgNi contacts. It has maximum contact current of 20A and is rated at 10A ac current with resistive load. The tested parameter was THD vs. output power at 1kHz into 4ohm and 2.2ohm resistive loads. Measuring bandwidth was 45kHz.

1. Load 4 ohm

Distortion is same up to 20W/4ohm. Then we can see and effect of nonlinear contact...

• pma
• Replies: 0
• Forum: Amplifiers, Phono preamp, and Analog Audio Review

• 

I'm not sure relays (where repeated arcing occurs) are relevant to connections in an audio system. And in any case, the extremely small difference at rather high wattages are nowhere near the realm of audibility. In fact, where the amplifier starts clipping and distortion starts getting into potentially audible territory, the difference between the two materials becomes negligible to non-existent. We're also talking about line-level signals here.

 

[solderdude]

Headphone currents are in the mA range unlike speaker relays.
Power relays (mains, car battery etc.) are an entirely different thing.
The contacts don't slide either, they just land on top of each other.
For relays selecting the right relay(contacts) for the job is important.

Material	Description	Best For	Drawbacks
Silver Nickel (AgNi)	Silver with 10% nickel, good balance of conductivity and durability.	General-purpose relays, resistive loads	Tends to oxidize at higher temperatures.
Silver Cadmium Oxide (AgCdO)	Effective in preventing welding, especially for high inrush currents.	Inductive loads, motors, contactor coils	Phased out due to cadmium content.
Silver Tin Oxide (AgSnO₂)	Great resistance to welding, ideal for high inrush currents.	Circuits with high peak currents	Can wear under DC loads.
Hard Silver Ag	Silver mixed with copper and nickel for increased hardness.	General-purpose relays	Oxidizes at high temperatures.
Silver Tin Indium (AgSnOinO)	Improved version of Silver Tin Oxide, even better for inrush currents.	Power circuits with large current surges	Less common, more expensive.
Tungsten (W)	High resistance to welding and burnout under heavy loads.	High-power applications	Expensive, less conductive than silver.
Gold Plating (10µm Au)	Thin layer of gold for low-power applications.	Low-power relay contacts	Wears off after ~1 million cycles.
Gold Plating / Flash (3µm Au)	Thinner gold layer for corrosion protection during storage.	Low-power relays, infrequent use	Less durable, wears off easily.

I have had to replace quite a few speaker output relays (back in the day at least) so these relays are often problematic after years of usage.
A give-away is that when there is no sound or soft (distorted) sound is heard and the volume is turned up high shortly and then works fine till the next time it is switched on.
For speakers arc voltages (and currents) are right in the 10V-14V and 2A range.

For headphone connectors the contact surface area is small and the contact pressure not very high but because of the small contact surface area the contact could be fine.
The contacts slide across each other rather than what relay or switch contacts do.
Voltages usually do not reach arc voltages and currents rarely exceed a few hundred mA.

I have very often encountered poor contacts with TRS jacks too (they are notorious for that).
It really does not matter if the plugs/sockets were silver-, gold- or nickel-plated.
In such cases rotating them or unplugging and plugging helps.
When that happens cleaning the plug usually helps.
Contacts of plugs easily get smudged.

 

[pma]

In any case, the answer is always the same: it really just does not matter. The small differences in conductivity are irrelevant when you have such a large cross-sectional area making contact. You're

If you really did the tests with power amplifiers, you would know that relay contacts quickly deteriorate with every contact arc discharge. These relays under test were almost new. After some time and several arc breaking, the distortion rises to 0.01 and 0.1% order and finally the contact stops to conduct the current. I have always wondered why people with no experience in the field need to display their opinions. Better to learn.

 

[kyuu]

If you really did the tests with power amplifiers, you would know that relay contacts quickly deteriorate with every contact arc discharge. These relays under test were almost new. After some time and several arc breaking, the distortion rises to 0.01 and 0.1% order and finally the contact stops to conduct the current. I have always wondered why people with no experience in the field need to display their opinions. Better to learn.

I think you should probably actually read my comments before telling me to learn.

 

[Hiten]

Be gentle newbie query.
what I thought is that when amplifier is turned on (No music) the relay to connect speaker makes contact , but there is no signal. After that one starts to play the music. Would the relay still produce arc with no signal or current ?
regards.
addition : In amplifier power on switch I see capacitor to suppress arc. would that work for relays ?

 

[Multicore]

what I thought is that when amplifier is turned on (No music) the relay to connect speaker makes contact , but there is no signal. After that one starts to play the music. Would the relay still produce arc with no signal or current ?

If the amp is not defective then no signal means it generates no potential difference at its output so it cannot be responsible for an arc. (Zero volts, Ohms law, therefore zero current.) However, something connected to the output terminals could provide a potential difference, unlikely with loudspeakers connected but if you hooked up a Van der Graaf generator then maybe.

 

[Multicore]

Headphone currents are in the mA range unlike speaker relays.
Power relays (mains, car battery etc.) are an entirely different thing.
The contacts don't slide either, they just land on top of each other.
For relays selecting the right relay(contacts) for the job is important.

Material	Description	Best For	Drawbacks
Silver Nickel (AgNi)	Silver with 10% nickel, good balance of conductivity and durability.	General-purpose relays, resistive loads	Tends to oxidize at higher temperatures.
Silver Cadmium Oxide (AgCdO)	Effective in preventing welding, especially for high inrush currents.	Inductive loads, motors, contactor coils	Phased out due to cadmium content.
Silver Tin Oxide (AgSnO₂)	Great resistance to welding, ideal for high inrush currents.	Circuits with high peak currents	Can wear under DC loads.
Hard Silver Ag	Silver mixed with copper and nickel for increased hardness.	General-purpose relays	Oxidizes at high temperatures.
Silver Tin Indium (AgSnOinO)	Improved version of Silver Tin Oxide, even better for inrush currents.	Power circuits with large current surges	Less common, more expensive.
Tungsten (W)	High resistance to welding and burnout under heavy loads.	High-power applications	Expensive, less conductive than silver.
Gold Plating (10µm Au)	Thin layer of gold for low-power applications.	Low-power relay contacts	Wears off after ~1 million cycles.
Gold Plating / Flash (3µm Au)	Thinner gold layer for corrosion protection during storage.	Low-power relays, infrequent use	Less durable, wears off easily.

I have had to replace quite a few speaker output relays (back in the day at least) so these relays are often problematic after years of usage.
A give-away is that when there is no sound or soft (distorted) sound is heard and the volume is turned up high shortly and then works fine till the next time it is switched on.
For speakers arc voltages (and currents) are right in the 10V-14V and 2A range.

For headphone connectors the contact surface area is small and the contact pressure not very high but because of the small contact surface area the contact could be fine.
The contacts slide across each other rather than what relay or switch contacts do.
Voltages usually do not reach arc voltages and currents rarely exceed a few hundred mA.

I have very often encountered poor contacts with TRS jacks too (they are notorious for that).
It really does not matter if the plugs/sockets were silver-, gold- or nickel-plated.
In such cases rotating them or unplugging and plugging helps.
When that happens cleaning the plug usually helps.
Contacts of plugs easily get smudged.

Thank you, @solderdude

Now I want a guitar cable with tungsten connectors. "High resistance to welding and burnout under heavy loads." "High-power applications." That's me!

 

[Hiten]

If the amp is not defective then no signal means it generates no potential difference at its output so it cannot be responsible for an arc. (Zero volts, Ohms law, therefore zero current.)

OK got that..
regds.

 

[Ropeburn]

Thank you, @solderdude

Now I want a guitar cable with tungsten connectors. "High resistance to welding and burnout under heavy loads." "High-power applications." That's me!

But but in a guitar cable you would probably WANT distortion.

 

[DSJR]

Rega's Roy Gandy was lightly ridiculed by us 'great unwashed' when their early (and current?) amps came along with plain nickel (plated?) RCA sockets. He made a spiel as regards gold plating adding another needless layer to the base nickel plated socket, making out that adding yet another posh looking layer would do nothing except look better. Nothing wrong here at all, but I bet he saved a few pennies per socket-bank in NOT having gold-plated terminals

 

[solderdude]

addition : In amplifier power on switch I see capacitor to suppress arc. would that work for relays ?

Yes it will and is actually done as well..
A capacitor (with or without a small resistor in series) or a Transient Voltage Suppressor or VDR across contacts also helps with relays in reducing arcing.
It won't in the output path of an audio amp as the load would always be connected through a high-pass filter.

Be gentle newbie query.
what I thought is that when amplifier is turned on (No music) the relay to connect speaker makes contact , but there is no signal. After that one starts to play the music. Would the relay still produce arc with no signal or current ?

Yes it will when the relay should be replaced. In this case an amp may not give any sound but will when you shortly turn up the volume loud. The contact then 'burns' a contact and will work fine until the device is switched off and on again. Time to replace the relay. It is a quit common error.

 

[OldHvyMec]

I'd like to know that the nickel doesn't add any distortion, especially when connected to gold-plated TRS jacks.

TSR jacks are not my first choice for any audio connection. They are too small for me, both male and female. I have to use them for the trigger portion of my stereo, and you have to be careful plugging them into some of the cheap female connections. I NEVER had that problem with 1/4", RCA, XLR, (most) banana or stud/nut threaded.

I have vintage McIntosh, Marantz, and Thoren gear that has 50+ year old nickel RCAs, all I do is clean them every couple of years.

I get the old snap, crackle, pop from time to time with RCAs, very seldom with 1/4", solid bananas, or XLRs.

If you want to secure the connection and stop future connection problems, use a contact enhancer. That is what 99% of the aeronautical, automotive, heavy-duty equipment, residential, and commercial electricians use. Especially if aluminum or two unlike metals are used when doing the build. Ex: aluminum main cabling onto a copper/? buss bar. You treat the cable or expect the barnacles somewhere down the line.

I've used contact enhancers for over 50 years. Just don't be sloppy with the application. MORE is not better, a thin coat or as instructed by the manufacturer is what you want.

Distortion? Only if there is a bad contact. SO, enhance the contact. Easy Peasy.

Regards

 

[Dutchy19]

I have a bunch of pretty decent balanced TRS to XLR cables. The XLR side has silver-plated contacts so I'm not worried about those (if there's any tarnishing I'm fine to just unplug-replug the connectors once in a while, though I doubt it'll be an issue). However, the TRS side has nickel-plated contacts, and I'd like to know that the nickel doesn't add any distortion, especially when connected to gold-plated TRS jacks.

Thoughts?

Worked for many years in the military HF (shortwave field). Conditions are far worse than your home area. Everyone buys the cheapest cables for testing, and installed equipment relies on quality coax and connectors but only for the strength — never ever heard of gold plated anything, and this equipment runs for decades without being touched. All of the test equipment (some worth $1M USD plus), uses standard non-gold plated connectors. And a lot of this equipment is used for GHz R&D, far far far above 20 kHz. Connector plating doesn’t matter, really.

 

[NTK]

Worked for many years in the military HF (shortwave field). Conditions are far worse than your home area. Everyone buys the cheapest cables for testing, and installed equipment relies on quality coax and connectors but only for the strength — never ever heard of gold plated anything, and this equipment runs for decades without being touched. All of the test equipment (some worth $1M USD plus), uses standard non-gold plated connectors. And a lot of this equipment is used for GHz R&D, far far far above 20 kHz. Connector plating doesn’t matter, really.

Really? Are you familiar with MIL-PRF-39012 ( Connectors, Coaxial, Radio Frequency, General Specification for (w/Amendment 4) )?

 

[solderdude]

Gold plated mil connector. Also are made with nickel-plated contacts but those are intended for mobile usage where connectors often are plugged in/out.