Well, many of you might have seen the gold plating on connectors like HDMI cable even on you 3.5 mm jack of earphones. Usually you will find the gold plating in expensive items and the manufacturer companies also specifies this on the box of the item or some time the shopkeeper also tells you about that. Some of you might have thought why it is done and some of you may have ignored. Well if you don’t know then you are at right place.
Well, for proper connection, the connectors should have good conductivity. Gold has superior conductivity. If we look in metal conductivity table then Silver comes very first and after that Copper and then Gold.
The question might have arisen in your mind that why Silver or Copper are not used, they have more conductivity then Gold. As we all know the Silver is quite expensive then Gold so they are not used. You might have seen Cooper are used for transmission but they are not used for connectors. The reason is here:
Connectors are fully opened and exposed in the environment while in wire we can cover the copper wires with plastic layers. As connectors are opened so they should not react with atmosphere. Connectors are inserted in socket for a thousand times so all you need is, there should not be any wear and tear, the conductivity should be well 100% so that your signal should not get distorted and the bonding will be well and perfect.
Since the connectors are fully opened and exposed so Silver, Copper or Tin may get oxidised with oxygen. They have good chemical reactivity so they may get reacted with air, oxygen, atmospheric moisture which will results in the formation of extra layer on the start of the connectors. This will results in the distortion in signal and will reduce the conductivity. If we talk about Gold, it has low reactivity. Gold normally does not react with Air, Oxygen or moisture present in atmosphere. Even when we consider wear and tear factor, Gold has very low. So Gold is the best metal that is used for plating in connectors.
What you can conclude?
You won’t observe the much difference in sound quality of your earphones in normal plating. But when you use for large instrument you may see the difference in Gold plating and normal connectors. You will never observe any type of distortion or interference between your signal in gold plated. For long term use Gold plating is very superior to use you can go for normal plated connectors also but these won’t give you a perfect output for a long time.