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THE GREAT AC OUTLET SHOOTOUT.

Just to satisfy my own curiosity and because of the very passionate debate by some relating to this issue, I have decided to perform a controlled listening test of AC outlets, basically most of the ones suggested in this tread AC Outlets that I could get a hold of. I’m basically putting my own money where my mouth is.

I have procured the following AC outlets, all are new and unused.

Audio Magic NanoStream, $ 69 and WattGate 5266i AC Plug $10

Porter Port by Albert Porter, $41 and TBD AC Plug $ ?

Furutech FPX-G $95, and Furutech FI-11M-G AC Plug $55

Pass Seymour CR6300 Cryo $44 with Pass Seymour 5366XCCV4 AC Plug $10

Teslaplex SE by Synergistic Research $95 and TBD AC Plug $ ?

Hubbell HBL5362-I Heavy Duty Spec. Grade Grande Duplex $16 and HBL5266C AC plug $10

Levitron 5362-W Industrial Heavy Duty Grande, Straight Blade, Self Grounding Duplex $7 and AC Plug Levitron 5266-C Industrial grade $10

El Cheapo HomeDepot Outlet $0.54 with “regular” Cheap moulded power cord $5

Technical Description of the Test:

To ensure that all the outlets will be equally represented in this test they will be mounted in a test fixture evenly spaced. They will all be fed via a single piece of 12 gauge romex cable directly hardwired to a dedicated 20 amp breaker in our main panel. The wire will be uncut when wired between the different outlets - basically simulating a “single run” dedicated line as only one outlet will be energized at any time.

As you can see if have ordered AC Plugs of the same manufacture and grade as the outlets, I have asked the suppliers of the Audio Grade outlets what AC plug they recommend to get the best performance from the outlet, that way there should be synergy within the - connection point - that is to be evaluated.

The AC plugs will be wired with 3x12 Gauge SJOOW about 12” long these will be hardwired to each their own 3 pole 20Amp relay that will be controlled by a PLC (programable logic controller) this to enable remote controlled switching between the 8 different outlets. The control will be programmed so that the next circuit will energize prior to the past one is de-energized to ensure uninterrupted current flow to the system that will be used for the test. The Complete Audio system will be fed from this one test jig, one outlet at a time. The individual power cords for each piece of equipment will be hard wired into a common terminal strip that is fed from the output of the relays. With this setup the ONLY variable is the AC outlet and its associated AC Plug. The test jig with the outlets will be run in prior to the test for at least 24 hours to insure “break in” for the ones that feel that this is important.

I want to run it as a blind test at first to ensure a completely unbiased result. As each outlet is energized it will be represented by a LED indicating that now outlet “A” for an example is energized, enabling the test panel to identify which outlet they deem the “best sounding”. Many of you have stated that the AC Outlet a Audio System is connected to profoundly changes the sound of the Audio System, so it should be beyond obvious to the test panel which one “sounds” the best. Later on the same test jig can be used for testing AC Cables should the opportunity arise.

We will use a Audio System similar to the system I have listed here on AudioGon for the test, it may change a bit by time of the test based upon what I have available at the time. The total current consumption of the system is in the range of 6 - 8 Amp at idle I estimate at this time but a complete listing of the system used, with actual current draw will be published here on this forum, along with the results of the test for those interested. System

The Test Panel:

On December 2nd. we will host the San Diego Music and Audio Guild here at our facility from 2P to 5P. We host that great group of folks here about every two years or 3 years, usually in December so this coinciding presents a great opportunity to do the AC Outlet test as there will be plenty of Audiophiles available for a unbiased opinion. I ran it by the President of the group this morning and he thought it would be a great thing to do along with of course auditioning our demo system in our factory show room, see and hear our new offerings, discuss audio etc. For more information about our facility you can go to our website and take a peak at the video, there is footage there from our showroom as well. Website

Everyone is welcome to participate in this catered event, there will be food and beverage served. Slider Burgers, Finger Sandwiches, Draft Beer and Soft Drinks etc. If you want to attend just shoot me an email so I can plan ahead with the caterer making sure we will have enough for everyone.

If any of you have any suggestions on on how to conduct the actual test, ie how long do you think each AC outlet should be “on” for, how many times the test should be repeated etc. suggestions are more than welcome. Also, if you have any suggestions to as how the test jig could be technically improved, let me know and I’ll be happy to discuss further.

As Always, Good Listening

Peter
128x128pbnaudio
pbnaudio's avatar
pbnaudio OP
1,613 posts
 
Hello Jim

You bring up some valid points but what we will analyzing is the outlet by it self and all the outlets will have the exact same conditions under which they are to be tested, thus the "best" outlet will surely shine trough.

Vibration - The outlets are to be mounted on a 3/8" piece of acrylic plate - I truly do not believe that this will have any more vibration than the Drywall in your house to which an outlet is normally mounted, actually probably less.

Daisy chaining - There will be none, all the outlets will be connected to a terminal strip with the exact same length of wire. To the other side of that terminal strip a piece of 12 gauge romex will be routed to our main panel where it will be connected to a 20A dedicated breaker. I had originally wanted to feed all the outlets with a uncut piece of wire all the way back to the breaker but their connection points prevent this form happening.

Relay Contacts - Is a valid concern but I have decided to actually hardwire all the components but maybe the Transport to the terminal strip that is fed from the output of the relays bypassing both the AC fuse and the IEC inlets - the elimination of these additional contact points more than makes up for the inclusion of the 20 Amp relay contacts that will switch the outlets in and out. It is in my opinion FAR more important to be able to have a completely seamless switch between the different outlets to properly evaluate if they change the sound or if they don't. The powering down, changing wires, powering up etc. induces many more variables than this test do. Remember only ONE outlet will be engaged at any time but the 2 second overlap between the outlets to ensure that all important seamless evaluation of them.

If this test concludes that the AC outlet have little if any effect on the performance of a system, your post is already the first attempt of discrediting it of which I'm sure there will be a few because you probably will not like the outcome of it - IHMO

Cordially,

Peter
mapman's avatar
mapman
22,317 posts
 
This will be interesting!
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drubin
3,274 posts
 
I applaud this test. There is no way to make it perfect but you are doing an admirable job of it.

On the off chance that there might be some differences (though I don't see how it could be) you should do amplifier output level matching (electrically) between the outlets. If there are differences, you will want to find a way to compensate for them.

I think you should also try the test with several different audio components, e.g., two different source components, two different amps, etc. Or at least with an amp and a source component. (Maybe you already discussed this.) You will need to do output level matching again or at least be careful about making sure that variations in loudness do not become a variable in the listening evaluation.

I think you already have too many outlets in the test for good experimental design. When we test a lot of concepts in online surveys, we use multiple respondent samples and expose each sample to a subset of the concepts. This is because respondents lose interest and ability to discriminate at the number of tests goes up. In your case, testing with multiple components just adds to the complexity. So you need to think about breaking the test into smaller chunks, such as comparing and scoring two or three outlets at a time, then throwing that "winner" in against 1-2 new ones.

There is also the phenomenon of "order bias." If you test the same outlets with different listening panels, change the order in which the outlets are heard.

I have a few additional thoughts, based entirely on my own experiences of comparing things in my system:

First, do not make rapid switches between outlets. Allow a brief pause.

Second, use short musical selections, If you are using digital, you can prep selections that are clipped to desired length.

Third, do not use the same musical selections for the entire test. I realize this may be controversial, but I have found that it's important to add new material while dropping some of the old stuff as you move through a series of comparisons. The discards can re-appear later on. My hypothesis for why this matters is that the experience of hearing a selection for the first time in the context of a test is very different from hearing it for, say, the sixth time, or even the second time. There is something about "newness." Every device under test should get the benefit of something new in the mix in addition to selections you have heard with the preceding device.
brownsfan
1,508 posts
 
Peter, I hate to see you go to all this effort if everyone is going to approach this from a dogmatic rather than an empirical point of view. This experiment should provide a well conceived data point. It won't and can't provide a once for all answer. As I said earlier, a positive result only shows that under some circumstances one can hear a difference. A negative result shows that under the conditions of the test the listeners did not discern a difference with statistical significance.

I wish I had saved the outlets that sounded so bad in my house. I would have bet money that people could have heard a problem with those outlets.

Regardless of the outcome of your test, its unlikely I will be pulling the AM nanoplex's out of my house, and its equally unlikely I'll be spending 1K apiece for the latest and greatest duplex.

At 40-60 bucks each, the bar isn't very high for demonstration of cost effectiveness. I got a easily audible improvement for $40. Its not clear to me why people are making such a big deal out of this.
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