Audiophile Grade Wall Receptacle

Clamping strength and the metals and plating used are probably the two biggest factors in how an ac receptacle might possibly affect sound.  I am a proponent of copper, especially since all the wiring in front of the receptacle and probably the power cord after are copper.  Beryllium copper is a copper alloy, of which there several.   Copper alloys can improve on certain properties of raw copper, such as strength, hardness, and machining properties.  However, copper alloys are less conductive than raw copper and beryllium copper is only about 45 percent as conductive as copper (i.e., 45% of IACS).  Tellurium copper is probably the most conductive copper alloy at about 93 percent of IACS.  Beryllium copper is commonly used in spring contacts, hence ac receptacles.  Furutech uses a special nonmagnetic Stainless Steel Conductor Spring System that allows them to use pure copper conductors.

What attributes would an "audio grade circuit breaker" have that would make it different from a regular circuit breaker currently in use in the USA?  Can you post a link to an example?

@boxcarman 

Can anyone actually tell me they heard an improvement with audio receptacles?

Of course, everybody hears it, at least equal to a component change, what's your point? 

@retiredfarmer 

I know, I know, should’a put the doo-dads first.  I will catch on eventually.

The Furutech outlets are nice and Cardas outlets are also supposed to use a copper base  For copper on a budget, might also take a look at this one and this one.

It is interesting how certain things affect the sound we perceive. I struggle with the use of copper alloys having less than half the conductivity of copper as connectors when audiophiles make such a big deal about OCC vs. OFC wire, which has a conductivity difference of only about 1% IACS. The Furutech GTX-D receptacles use pure copper blades, as does the Cardas receptacle, which may explain why those have been so well received in the audio community for so long. Below is from the Furutech literature:

Of course everyone would love to make pure-copper receptacles, but its malleability – lack of stiffness – makes pure copper a poor choice. That’s why you’ll find less conductive metals such as beryllium copper, phosphor bronze, or brass in some receptacles. Furutech’s intense engineering scrutiny has resulted in an industry-first, a technique allowing us to use special Furutech 24k gold- or rhodium-plated α (Alpha) pure copper conductors strengthened and sprung by our innovative nonmagnetic Stainless Steel Conductor Spring System that keeps a firm grip yet won’t damage male connector blades or their plated surfaces. Even the screw-down pressure plates are curved to maximize contact area. The GTX receptacle can be summed up in a word; virtuoso!

@boxcarman and @retiredfarmer

Sorry - sarcasm was intended.  I use higher end receptacles just because. Can I hear a difference, probably not. Some of this stuff I just use in case I might be missing out on something, but I certainly do not sit around doing A/B comparisons or obsessing over the result. My general order of the factors I believe make the most noticeable improvement/difference in the sonic quality of a home audio system goes like this: speakers, electronics, room, supports/isolation/damping, cables, and finally other doo-dads and add-ons. The receptacles fall somewhere between cables and doo-dads - IMO.

@kellyp

Tellurium alloys are junk. Get a conduction chart for copper alloys and you will be shocked.

Huh? - Tellurium copper is by far the most conductive of the copper alloys at 93% of IACS. Here is a chart.

I have some Porter Ports here, as well as some Acme Audio Labs Ag Silver Cryo receptacles and one Furutech GTX-D G receptacle.  I suspect the differences are subtle and I don't really have a clear preference.

As to Rhodium vs. Gold vs. Silver plating, I suspect any potential differences may be due to the level of finish on the plating (polishing?) and maybe also how the current is transferred across the boundary.  Maybe the different platings impart a subtle sonic characteristic as some believe they do when used on speaker cable spades, etc.  These platings were mostly used for corrosion resistance in the early days, like the tin coating you can still find on some wires and connectors.  Other than silver, none of the other common plating materials conduct electricity anywhere near as well as copper, although gold comes closest at 76% IACS. 

Thanks for the video @mjcmt, I find this stuff interesting from a standpoint of how marketing and audiophile lore, i.e., stories told (not around campfires but) around these forums, have shaped opinions and purchases made by "audiophiles" over the years.

I am sitting here with three "audiophile" outlets, or AC receptacles, an older Porter Port, an Acme silver-plated outlet, and the Furutech GTX-D (G). Porter Ports were sold by Albert Porter and consisted of Hubbell outlets that were subjected to a cryogenic process. He originally used the 8300H outlets and later switched to the less expensive 5362W. Acme outlets have expanded to include a variety of styles including a heavy duty model. Common to all Acme outlets are their cryogenic treatment and silver-plated contacts, and a somewhat reasonable price for audiophile stuff.

The purpose of an electrical outlet wrt a home audio system is to provide a connection so that electricity can be conducted from your home wiring to your audio equipment power cord. As with any audio connector, this requires a combination of a strong grip and good conductivity.

The vast majority of these outlets use copper alloy (i.e., brass) contacts to provide the necessary combination of conductivity and strength. The PS Audio Power Port Classic AC Receptacle uses "15 coats of polished nickel over high-purity brass." The relatively lower strength of pure copper simply wouldn’t hold up to repeated plug/unplug cycles. However, the conductivity of brass is only about 27% of the conductivity of the ETP copper wiring in your wall, based on the IASC rating. Yes, there are several types of brass alloys, but even the most conductive is barely above 30% IASC. In addition, the nickel plating used by PS Audio is only about 24% as conductive as copper, vs. the silver plating used by Acme (106%), or even gold at 76% IACS.

One way to look at this situation, which is similar to speaker and IC cables that use less conductive connectors, would be to say the path or area of the connector is much less than that of the intervening copper wiring so the connector should not have as much sonic influence. The audiophile outlook would probably be to say "everything matters", which brings us to the Furutech GTX outlet, which is able to use copper connectors because of a unique spring loading mechanism used to grip the plug blades without requiring repeated strain on the copper contacts themselves.

I found this 2003 article from Stereophile where Art Dudley writes about the PS Audio Power Port Classic AC Receptacle. He concluded:

Is there enough of a performance difference to justify the trouble and expense? All things considered, yes: I heard the Power Port make a small, subtle, yet very real improvement in sonic performance. The difference was consistently audible with a wide variety of products, and I’m hard-pressed to think of another way to improve a hi-fi system for just $50.

So the improvement was "subtle, yet very real." More campfire talk, IMO. I find it hard to believe that Art Dudley could pick out the difference between the PS Audio Power Port and other receptacles that are mostly the same except for the nickel plating (24% of IASC) used in the PS Audio receptacle. I have an easier time believing the Acme receptacle with silver plating and cryo treatment could possibly make a sonic difference as could the Furutech which uses copper base metal for the contacts.

In summary, I agree with @mijostyn, the Hubbell 8300 provides excellent grip of the plug blades, which is one of the two most important jobs of the outlet (grip and conductivity). Only a few receptacles address the conductivity issue such as Furutech (and any others that use copper contacts), or Acme with their silver plating. Making something shiny (i.e., nickel or rhodium) does not make it more conductive. Look at the IASC rating of the metals used in your outlets (and your AC plugs) to assess conductivity. If I were in the market for outlets, I would probably purchase the Hubbell 8300 and be done. If I was willing to pay a little more, I would try Acme’s heavy duty outlet with thick silver plating, and which has been cryogenically treated. If I wanted to spend a lot more, I would use Furutech GTX (G) outlets, which are constructed using copper contacts. However, anything beyond the Hubble 8300 may simply be campfire talk - IMO of course.

Lots of reasons to like Furutech you can read about here. Cost is $225.  I doubt the delta in sound would justify the delta in price between that and the $3,100 Quantum Science outlet in my system.