Connector materials - Affect on sound?

[earwaxxer]

I just found this - kind of interesting..
http://store.curiousinventor.com/guides/how_to_solder/kind_of_solder/


"Silver bearing solder: (that is, contains silver, not for roller bearings) Silver is used in one of the leading alloys for lead free solder (An96.5% Ag3.0% Cu.5%) and also as an addition to tin-lead solder, usually in the 2-4% range (when you se 62/36/2 this means Sn64Pb36Ag2).

People claim that it flows better, has a lower melting point, is stronger, and has a higher conductivity. According to Indium's solder wire data sheet, their 2% silver solder has an electrical conductivity that is 11.9% of Cu compared to 11.5% of 63/37 tin-lead solder, a shear strength of 7540psi vs. 6200psi, and a tensile strength of 7000psi vs. 7500psi for 63/37. So, yes, the claims are true, and also mostly insignificant. Silver was initially added to solder to prevent silver platings on component leads from dissolving into the solder ("silver migration") and forming brittle joints. Having silver in the solder reduces migration, so you may want to use it on silver joints. (Note: this logic doesn't entirely make sense to me. If silver getting in the solder caused embrittlement, how does adding more silver prevent this?)

Audiophiles seem to be enamored by 4% silver bearing solder, namely some from WBT, Cardas, and WonderSolder. Are these really better for audio?

The superior claims include things like higher purity, eutectic alloys, higher conductivity, and better flux. I haven't found any controlled studies showing that a group of people can actually hear the difference, so I'm skeptical. Although additional silver does increase conductivity, the increase is small and the joint distance over which that conductivity applies is also extremely small. For what it's worth, here's a forum discussion that discusses a bit about solder in high-end audio and also a FAQ (scroll down)concerning solder on Cardas Audio's site. Another decent discussion.

Bad joints made with any solder can create a high-resistance connection, especially if the underlying components were heavily oxidized initially. My advice: if it makes you feel better, get it, but be wary of sellers that don't provide spec sheets."

[4krow]

Annnnd, were baaack to connnecTIONS!(spoken like at a boxing match).  So, as Grainger once said, make a good mechanical connection before soldering. I totally agree with this idea. It is not always possible, but even then, I like the wire to be touching the connection, and not relying solder to hold it in place. Having said all that, solder is what we got most of the time to make a connection with. Suffice it to say that the joint needs to be clean before you worry about the chemistry of the solder.

[Grainger49]

We are supposed to get a good mechanical connection then solder it to keep it in place.  As much as I used to believe it solder is not electrical glue.

[Downhome Upstate]

Hmmm, but I've seen folks elsewhere take the opposite position, i.e., that the best connection is the best mechanical one (crimping with the kind of force that produces a 'cold weld', without solder.)  Is that just the cable manufacturers bragging on their hydraulic crimp presses?

[KevO]

I have not listened for differences in connector materials. Not sure I could hear any.

I have been building interconnects with Eichmann plugs because they have small conductors.

Hardly makes sense to use 28 ga. wire (VH Audio Spectrum) and then drop the signal onto a huge block of metal.

I've grown to despise locking RCA jacks and stiff, heavy wire. And these sound fine to my ears. YMMV.IMHO, etc.

Kevin

[4krow]

I usta use one of those hydraulic crimpers at work. It work produce 14 metric tons of pressure! Once, it locked upright in the middle of a crimp. I was thinking maybe I could just a couple hundred rolls of tape and hide it, but quality inspectors are so friggin picky. Like they know so much. Point is, you might get the crimper off the half crimped cable, but it will take a saw to get even a half crimped crimp off the cable! Pretty freakin good connection I'd say. With the right connecters and tools, I do believe that it is possible to do just fine.

[Downhome Upstate]

I usta use one of those hydraulic crimpers at work. It work produce 14 metric tons of pressure! Once, it locked upright in the middle of a crimp. I was thinking maybe I could just a couple hundred rolls of tape and hide it, but quality inspectors are so friggin picky. Like they know so much. Point is, you might get the crimper off the half crimped cable, but it will take a saw to get even a half crimped crimp off the cable! Pretty freakin good connection I'd say. With the right connecters and tools, I do believe that it is possible to do just fine.

Watch your fingers!

[Armaegis]

Silver was initially added to solder to prevent silver platings on component leads from dissolving into the solder ("silver migration") and forming brittle joints. Having silver in the solder reduces migration, so you may want to use it on silver joints. (Note: this logic doesn't entirely make sense to me. If silver getting in the solder caused embrittlement, how does adding more silver prevent this?)

While I don't know the specific metallurgical/embrittlement reaction taking place there, atomic diffusion/migration of any sort is usually unwanted. I would imagine for silver plating which is very thin that this could affect the adhesion of the plating to the base metal as well. Any sort of concentration gradient can also lead to unwanted microstructures developing. Having the silver content in the solder in the first place would be enough to minimize diffusion (and my guess is that the unwanted stuff was happening in the 1-3% range anyways, so if the solder is at 4% then there's nothing to worry about... and a quick glance at a silver-lead phase diagram shows the eutectic point at 4.5% Ag, so there's that).

Hmmm, but I've seen folks elsewhere take the opposite position, i.e., that the best connection is the best mechanical one (crimping with the kind of force that produces a 'cold weld', without solder.)  Is that just the cable manufacturers bragging on their hydraulic crimp presses?

Well the best connection really is no connection, so an actual weld would be most ideal. I don't know if a crazy hydraulic press would necessarily be the best method though. I imagine a spot welder would do the trick as well.

[Downhome Upstate]

So, FWIW, based on Eric's tip I picked up "high-quality copper" rhodium plated RCA jacks from hificollective.com for $26.64 a pop (they look well-made), and Cardas CCRR-S silver & rhodium plated copper billet dual binding posts for $52.49 ea. (good price, BTW).  Finishing-off the connector round-up were 3 sets of Neotech DG-203 gold-plated OFC copper RCA plugs from pcx. They discounted them 20% to $40/pr., pretty hard to beat if you don't need plugs able to accept larger wire (using Belden 89207 twinax, which is less than 7 mm o.d.).

[earwaxxer]

Hey Mike - I did get those sockets installed by the way. As far as 'sound', Thats a bit hard to say. What I think I am noticing is a slight lack of 'harshness' and a bit better and bigger staging. They seem to just get out of the way. Not as big of a difference than say a tube roll or a cap change. Well worth it though IMO, although if they cost $200 for the set of 4 I'm not sure they would be worth that much.

[Downhome Upstate]

Eric,

I 'hear' you. I doubt I'll be able to tell the difference by substituting well-made connectors with better materials. What the heck. I thought it probably couldn't hurt while I was inside the Seduction changing coupling and output caps (not to mention replacing one of those tiny little 1 uf 50 v ceramic caps on the tube socket that I snipped by accident while trimming the lead on a resistor. Its still connected, but only by a solder blob). 

[Downhome Upstate]

Well, wrong again. Replaced the stock RCA jacks with the copper/rhodium stuff from hifi collective, and I can hear the difference. Much better contact has got to have something to do with it (one pair of the stock jacks had an intermittent loose center pin connector that was a real pain in the ass). I'm hearing better leading edges, more clarity overall. So I didn't waste the money after all. Go figure.

[4krow]

 Hmm, I thought that I might be the only one who was critical of the loose connection of the original jacks. I found the same thing. And the new connectors have a great center pin grip. That is the one that counts most.