Having recently dismantled and reinstalled our system I noticed that the silver plated 4mm speaker plugs in particular were badly tarnished. This seemed however mainly to be on the exposed metal areas rather than the parts actually in contact with the sockets. I was wondering what people use or recommend to safely remove this tarnishing, without leaving behind any deposits which might affect sound quality. Any suggestions?
I don’t use any plated plugs just single metal then polish with Brasso until it stops going black then wipe with clean white cotton “ shows residue stopping “ that’s it
In the case of my 4mm banana plugs that can tarnish in the open I put O rings on the exposed parts like below.
Before and after. 
3 Likes
Abrasion via reinserting many times or 100% IPA
Tarnished silver is not a problem, as you noted the contact areas are still untarnished, just a simple unplug and plug back in again is all you need. Basic soapy water will remove the tarnish.
I have silver DIN plugs, I pretreated the plug pins (only) with DeOxit and they have never tarnished.
However wherever possible I would ALWAYS avoid dissimilar metals, silver banana pins in brass or gold or nickel plated sockets, in normal room humidity and alkaline from one of the metal’s is liable to set up an electrolysis reaction that you will not fix.
1 Like
Silvo. Sorts it in 30 seconds.
1 Like
I wonder if silver Deltrons might be pretreated as they haven’t tarnished either.
I have a box of large and small bucket Deltrons in nickel, silver, and gold to match to whatever the terminal is. Some brass ones from another brand too but rarely used.
1 Like
Yes and I was aware of this. However my Chord speaker cables came ready made with the Chord 4mm plugs which are silver plated. I believe Super Lumina speaker cables also have silver plated 4mm plugs. How many speakers or amps are fitted with silver plated sockets? Very few I’ll wager. Gold yes, but I’ve never seen silver. Which begs the question why fit silver plated plugs to cables that will almost certainly be plugged into gold or maybe nickel plated sockets?
1 Like
The tarnish is a protective layer.
Leave it alone.
Charge more for them.
Manufacturers sockets are usually nickel or gold plate.
Chord ohmic plugs are not on my radar.
Silver is softer than gold or nickel.
Silver plug will score when inserted into a nickel socket, creating a clean contact.
Scoring will occur, but to a lesser extent if socket and plug are the same hardness.
I see a lot off misconceptions when it comes to speaker plugs.
I’m surprised to hear you use Brasso. I’ve used it in the past but not on anything hi-fi related, and I agree it’s excellent at removing tarnishing. Trouble is it contains oils, paraffin oil I think (it certainly smells like paraffin) and my concern using it on plug contacts of any sort would be that an oily film is deposited which can be extremely difficult to remove completely.
Contains isopropyl alcohol 3–5%, ammonia 5–10%, silica powder 15–20% and oxalic acid 0–3%
That’s why I said white cotton afterwards with isopropyl alcohol no marks and no smell.
Sockets and plugs are like mirrors.
I wouldn’t use it on plated metals only solid.
I only do them once a year or when the system gets stripped for a good dusting.
I wouldn’t use Brasso for anything electrical, the residue film is always a problem and it’s abrasive.
I Simichrome for the brass at home. It works on various metals (brass, chrome, silver, etc.) and leaves a clean, bright finish without residue.
Alternative is make paste with lemon juice & baking powder, if well buffed (polished) it leaves no residue.
Seems like horses for courses.
Abrasive then clean.
Simichrome is a soft, engineered metal-polishing paste containing aluminum oxide abrasives, kerosene, and white spirit
. 
Also listed are Tall Oil and petroleum distillates.
It’s been decades since I’ve used any but I know it certainly smelt strongly of paraffin back then.
What you don’t mention there @Skeptikal is what the other over 30% of Brasso consists of. It’s Aliphatic Hydrocarbons, of which Parrafin falls into perfectly.
Anyone wanting to actually clean any electrical contact should just simply use 99% Isopropanol Alchohol. It’s what the entire electronics and computer industry has used since year dot and for very good reason. It’s dirt cheap, it works, it evaporates very quickly and it leaves 0% residue. Anything else, including Brasso, costs more and will defo leave residue (even if you wipe it with a cotton cloth).
That’s why I said white cotton afterwards with isopropyl alcohol no marks and no smell.
I only use the brasso for abrasion.
1 Like
But you shouldn’t need “abrasion” The act of pulling the plugs in and out should be doing that on it’s own. You should only need to then clean with IPA. Even then, the IPA may not even be needed, it’s only a belt and braces thing.
Sorry I didn’t make my point very well, I don’t use any cleaner on electrical contacts. it’s not needed. I will apply DeOxit on new items as it does retard any surface tarnish in the future. Apart from that an annual pull and reinsert is all that’s needed. It works to some extent on the pressure contacts such as power sockets, but more especially so on the knife edge designs as we have with DIN and the Deltron side spring.
