I am studying on binding posts and I found a common point for high quality (or expansive). They are either made by pure copper or silver. I know that pure copper and silver are good electrical conductor.
If I have binding posts made in pure copper and brass with the same design, is the pure copper one must be a better binding posts?
If I have binding posts made in pure copper and brass with the same design, is the pure copper one must be a better binding posts?
Copper will eventually oxidize, which isn't desirable for making reliable electrical connections. The difference in conductivity between most metals and alloys is surely negligible, given the thickness of the parts and the very short distances involved. I'd prefer a heavy gold plating throughout, though some premium binding posts use rhodium, which may be more durable.
Usually, sound wise, yes.
While good quality (high copper content) brass sounds really good, pure copper sounds fuller, more focused with a blacker background.
Not a night and day difference but noticeable.
Best ones are those with low metal content made by Wbt and Furutech, IMHO.
As Damon Hill noted, avoid the ones without plating, when oxidized they will sound harsh.
I am actually seeking a way to self make a better binding post, at least better than those made by brass. I have tried to contact some of the Chinese factories, they said that they don't know anything about the relationship between materials choices and performance. They usually pick brass as the materials since they are easy to be machined.
When I tried to search for different brands, e.g. wbt, furutech, eichmann tech, they usually use metal plated pure copper as their signal conductor.
Therefore, I have a question, are the metals with high conductivity the better binding posts (in terms of signals transmission)?
I agreed with you that copper itself will oxidize at the end. What if I make a post with pure copper and then plated with gold or nikel. Would it perform better than rhodium in term of signal transmission performance?
However, when the binding posts are metal plated, the signal can be affected due to skin effects. The high frequency signal transmitted at the surface while the low frequency signal transmitted at the core region. The resistance encountered by these two signals should be different. would this causes any significant phase different between high and low frequency signals?
At the kind of currents you are sending to a speaker in normal operation, the material choice isn't particularly important.
You need posts that are able to properly secure the incoming cable and/or any terminating hardware. The pressure needs to be repeatable after multiple insertions, the post should tolerate over-tightening as well as a small amount of under-tensioning without stripping the thread or losing grip on the cable/termination.
Copper is usually too soft to machine, and even if you manage that, the thread is more delicate and you have to be a little careful. WBT uses high-copper alloy, not pure copper. Far as I know the only people manufacturing out of pure copper are Cardas, and the posts are designed to cut into spades and bare wire so that even after oxidisation the mating contact is 'fresh' copper.
The key to a good binding post is mechanical, not electrical. Even the cheapest binding posts will have similar electrical properties to the most expensive ones, but in use the latter stand out because of the ability to apply correct torque, the ease of insertion and removal, and the fact that will last a thousand insertions before wearing out.
Far as materials go, brass has a sufficient amount of copper in it to ensure good conductivity. If you do use copper, you may have to add a small amount of other metals to harden it so it can take some abuse. Plating is not needed if you design the post correctly, and if you do plate it choose the plating material depending on application. Silver for lots of insertions and removals, gold for domestic use to prevent against corrosion, and rhodium for the best of both worlds.
You need posts that are able to properly secure the incoming cable and/or any terminating hardware. The pressure needs to be repeatable after multiple insertions, the post should tolerate over-tightening as well as a small amount of under-tensioning without stripping the thread or losing grip on the cable/termination.
Copper is usually too soft to machine, and even if you manage that, the thread is more delicate and you have to be a little careful. WBT uses high-copper alloy, not pure copper. Far as I know the only people manufacturing out of pure copper are Cardas, and the posts are designed to cut into spades and bare wire so that even after oxidisation the mating contact is 'fresh' copper.
The key to a good binding post is mechanical, not electrical. Even the cheapest binding posts will have similar electrical properties to the most expensive ones, but in use the latter stand out because of the ability to apply correct torque, the ease of insertion and removal, and the fact that will last a thousand insertions before wearing out.
Far as materials go, brass has a sufficient amount of copper in it to ensure good conductivity. If you do use copper, you may have to add a small amount of other metals to harden it so it can take some abuse. Plating is not needed if you design the post correctly, and if you do plate it choose the plating material depending on application. Silver for lots of insertions and removals, gold for domestic use to prevent against corrosion, and rhodium for the best of both worlds.
Exactly. Hard and chemically inert metal that can be torqued down ensures a good, reliable connection.
If good contact strenght is also present, IMHO yes.
Marketing infos about low mass advantage are about micro-arcing and Eddy-current reduction.
Good engineered low mass connectors (see the extract from WBT datasheet I've attached) have a firm and sure connection for bananas, spades and plain wire.
Also very well considered are Mundorf ones:
An externally hosted image should be here but it was not working when we last tested it.
(Pic from Mundorf website)
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Brass plated steel seems to approximate that description, which means that the brass over steel 5 way binding posts sold oh-so-cheaply on eBay would seem to have some merit:
10pcs Terminal Binding Post Power Amplifier Dual 2 Way Banana Plug Jack NI5L | eBay
Pure copper is a stinker. Bad to machine, galls, seizes- just a lousy choice. Much better is an alloy like this- C14500 Tellurium Copper Alloy | C145 Tellurium Copper Rod and Bar
Then get it plated if you like, remembering that gold is really only good if it's thick enough not to wear through ($$) and at it's best when mating to some other gold plated lug.
Then get it plated if you like, remembering that gold is really only good if it's thick enough not to wear through ($$) and at it's best when mating to some other gold plated lug.
Is brass plating steel possible?
The seller somewhat dubiously claims that these posts are solid copper.
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What do you mean by applying the correct torque?
Do the best secure connection require large (or ideally, infinitely large)torque?
Are my following conclusion correct?
To make a good binding post,
1. The most important point is to ensure a good connection first. The post can be made by hard and inert metal such that no oxidation occurs and the wire can be screwed tightly.
2. Second important point is to ensure low mass content in order to reduce eddy-current.
3. The conductivity of the materials is the least important.
Am I correct?
I actually have a copper T2 in hand. Do you also mean that the thread will be deformed easily?
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I also don't know why Chinese vendors usually claim non-copper posts as copper either.
I have searched many vendors via alibaba and taobao in China. I can't find any vendors are providing post made other than brass.
Hard to torque down plastic. I use brass posts from Tiffany, which can be tightened with a wrench.
Not really, no. Unrelated, and eddy currents are irrelevant.
Mmmh. I think you should first decide what you want.
A good connector is simply a gold plated high copper brass alloy one which can accept bare wire, bananas and spades with a tight connection (IMHO the torque you can apply with hands is usually enough).
Low mass and better metals only enter game if you want an excellent and high-end connector.
Tellurium copper is an excellent choice if you want to make a machined connector, otherwise a low mass one (similar to WBT I've attached earlier) could be made easily made with pure copper.
Pure copper will be slightly better than tellurium copper, soundwise.
So, IMHO, the path should be:
- choose a target (good/highend)
- choose a design type (low/high mass)
- choose a material according target and design type
- Alway use plating (gold or rodhium)
Only a good one? Use high copper content brass.
Do you want an excellent (and overkill) low mass connector? Use pure copper and plastic.
Ponoma (a Fluke subsidiary) makes very good quality tellurium copper binding posts (Mouser 565-3770-0 and 565-3770-2) with very reasonable price.
(pic from Mouser website)
At this price, I would not use nothing less.
Maybe there's a different reason but WBTs I've linked to my ears sounds better than high mass copper ones from CMC USA, which sounds better than CMC brass ones, which sounds better than generic chinese brass ones.
Yes, I know, I'm fooling myself... 😉
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