DualTriode
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Hospital grade cord caps with shielded cord will have all the UL certs that you can use, plus be beyond good enough.
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GR Research B24 AC Cord Review
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AndreaT
Addicted to Fun and Learning
The wrong-size grounding pin is particularly concerning. Grounded equipment is not a fail-safe prevention of electric macro-shock: once the G receptacle has been damaged by the oversized ground pin, it might not work properly (i.e. you have an open grounding circuit) when a new and correctly designed power cable is plugged in. So, you might receive the full 15A through an energized metal case. The silver lining of course is that you would go to audiophile Heaven and enjoy endless debates on the value of triode amplification and rare woods resonators…
Another scientific and impeccable test by Amir!
Another scientific and impeccable test by Amir!
The most I ever paid for a cable was for charging my car. It was €15/meter for 3x6 mm2 (10 AWG), very nicely packed though. The ground cable that I laid for the same purpose was only € 2,85/meter for 3x10 AWG, fully braided and all.
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Get pkane's Deltawave, it does subsample adjustment. It is what Amir used and it costs nothing. Works with unsynched clocks.
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You can get this or similar 6 ft or 10 ft 14 awg hospital grade UL-cert cables from Amazon for like $17 or less. And it won't destroy you outlets or gear nor weigh too heavily on it.
The longer i look at this the less sense it makes.GR Research B24 Measurements
Company talks about how their cord "filters" other noise. Since your electronics performs strong filtering of its own, such a thing is not material. But for grins, I tested the worst case of treating the AC cable as an interconnect and putting a powered transformer right next to the cable:
The GR research B24 is indeed less receptive to AC noise inducement. As shown though in green line, even if you used any of these AC cord as an audio interconnect, their noise still be inaudible!!!
Waht is the scope of this test?
To me it looks like your trying to test the cables inductive noise pickup?
Doing so by injecting a unknown signal of unknown strength via a unknown transformer in unknown distance.
And for some reason you play a 1khz sinwave of unknown amplitude trough the cable at the same time
(Why not have no signal playing while measuring noise pickup to make used of the full analyzer input dynamic)
The 1khz signal of unknown amplitude is then arbitrarily defined as 120dB SPL?
What sense does it make to spend $$$$$$ to upgrade the power cable from wall socket to amplifier or preamp? What about the 20 miles of non-audiophile wire between your wall socket and the power plant?
Is there some food, radiation or maybe something in the water that is draining common sense out of people these days?
Is there some food, radiation or maybe something in the water that is draining common sense out of people these days?
We “don’t beat around the bush” in the UK - presumably it’s origin is something to do with hunting and driving fowl out of the undergrowth by hitting the said bush
The UK three pin plug has an overlong earth pin that opens shutters on the socket for the live / neutral pins - it’s a safely feature . I wonder if GC was trying to emulate this!
I really dislike heavy cables , especially signal cables . As you say , the mechanical strain they put on connectors is crazy. But hey - if it helps sell cable lifters so be it
The pin assembly used by GR seems to be fairly standard and generic.
The two examples below seem to have quite long ground pins and they are both U-shaped, not solid. Copper seems to be in fashion. The first of these costs about $1,000, the shiny one $40. Amazon.com lists plugs like that used by GR for $20.
Copper being one of the softest metals, I can't imagine it scratching anything. That's the problem with copper. For thousands of years mankind did not have "an axe to grind", as they only had soft copper that had to be hammered and easily blunted, they had to wait till the Iron Age before they could grind anything. I'm more curious about these solid copper connectors and how strong and long-lasting they are.
"Beating about the bush" was the preferred method to beating the bush itself, should something big jump out and bite you. It was more medieval Health & Safety than prevarication.
I bought a Furutech unswitched double wall receptacle about 15 years ago. It cost £80 and now is a staggering £226. I would still buy it. "Built like a brick shithouse", as we like to say. Difficult to get the plug in and you know it's not coming out without a lot of persuasion.
I would rather have robust connections. I don't unplug stuff on a daily basis. Almost never. My hifi is on a rack with wheels, so the spring clean does not require taking stuff apart.
My experience is more poorly made receptacles, not the plugs.
digicidal
Major Contributor
If so, it's been around for far longer than hifi gear has been (indeed predating electricity itself).
Although I certainly can't prove it, I'm reasonably sure there was a cave-dwelling ancestor of ours that convinced a neighbor that his rock tools were substantially different and better than anyone else's... because magic! And hey... if you can get 3 mammoth skins for the exact same thing someone else is giving away for free... who's the real fool there?
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That U-shape is common. NEMA 5-15P these and others are at Home Depot.
AudioSceptic
Major Contributor
Great, thorough review as always!This is a review, listening tests and measurements of the GR Research B24 AC cable. I purchased it from the company direct. It costs US $349 in the 4 foot section I purchased.
View attachment 218008
As the British saying goes, the B24 "looks the part" with the thick cabling and such. But fails in actual construction. When I attempted to first plug in the male end, it took incredibly force to push the earth/ground pin in. It it hugely oversized. It got progressively a bit better after a few insertions but then started to develop some scratches. Heaven knows what damage it has done to my outlet. Worse part was that when I first plugged it in, it was not passing any electricity! I look and it appeared to be fully inserted. Turns out it was not. There is this "shield sleeve" that slides forward pulling the heatshrink with it:
View attachment 218025
So looking from outside, it seems the plug has completely mated with the outlet. But in reality, hot and neutral pins have yet to make a connection. You have to simultaneously pull back the sleeve while attempting to push the whole contraption forward. Given the large force you need to put in there, it takes some gymnastics to be sure. This whole affair has gotten worse due to ground pin being too long:
View attachment 218010
Compared to my other AC cords, the ground pin is 1 to 2 mm is longer. This means that even though you feel like you have inserted the plug into the outlet, you have not yet. I can see this being done to support the crazy weight of these cables but come on. An cable should be easy to plug in and not remotely have such issues. So big fail on usability.
Company advertising says that you can try the cable out and if you don't like it, you can return it and "get your money back." Close look shows that you are responsible for shipping it back, the cost of shipping it to you and unknown credit card charges. I payed $40 for shipping for 2-day service ($25 for standard ground). So if I ship it back the same way, I will likely incur some $80. For this much money, could have bought a dozen ordinary AC cables. So much for money back guarantee.
And oh, those Velcro cables are mine in the picture. It doesn't come with any. I have bought cheap Chinese cables that came with set of Velcros.
Company makes two sets of AC cables, the B16 and B24 series. These are the number of wires that are put in the cable (or per line?). Strangely, despite its lower effective resistance, the B24 is said to be more suitable for sources/pre-amps than power amplifiers! So that is how I tested it.
GR Research B24 AC Cord Basic Measurements
I am going to do things differently than usual, starting with some simple measurements of the AC cord resistance and then jumping into listening tests, before showing more measurements. Here is the resistance of the cable as a whole and comparison to a few others I had on hand:
View attachment 218012
The large number of parallel strands creates a very low resistance cable. Total resistance was just 0.005 ohm or 5 milliohm. For later tests, I pitted the B24 against the worst opposite which was a generic and thin AC cable. It naturally had much higher (relative) resistance of 81 milliohm per meter (compared to 4 for B24).
If you pulled the maximum allowed 15 amps allowed out of the typical US outlet, you would get a voltage drop of 1.8 volt with my longer thin AC cable vs 0.08 volt for the GR Research B24. The former is just 1.5% drop which is negligible. Still, at 0.1% drop, the GR Research B24 clearly has lower resistance. The edge though drops substantially when you compare it to much cheaper aftermarket cables from Pangea and AudioQuest NRG-X3.
There are no regulator safety standards for the cable. The female IEC terminal has CE listing but the male end just says 15 amp/120 volt. Even if the latter was UL certified, the whole cable is not. So use it at your own risk!
GR Research B24 AC Cord Audio Tests
As a target, I used Topping A90 Discrete pre-amplifier. It has built-in power supply so accepts an AC cord directly. Switching from one cable to the other took too long to allow valid listening tests. Sometimes one cable would sound better. Sometimes the other. Sometimes they would sound the same.
Since you can't hear what I heard, I resorted to null testing. I used an RME ADI-2 Pro FS and looped its audio output through Topping A90 Discrete. Output of the A90D was then captured using RME's ADC. By using the same DAC and ADC, I removed clock variations, allowing for excellent nulling. Member @pkane 's excellent DeltaWave software was used to perform the matching.
First test was a classical record (CD) of Vivaldi's Four Seasons conducted by Christopher Warren-Green of London Chamber Orchestra:
View attachment 218013
The difference between output of the Topping A90D using generic thin AC cable and B24 was identical, resulting in just very low level noise at or below that of 16 bit CD content. Content is copyrighted but here is the difference file for you to listen to: https://www.dropbox.com/s/1qftq2r8bkw84hw/AC Power Difference.wav?dl=0
Next I tested the track Hunted from one of my favorite bands, Radical Face and their Missing Film album:
View attachment 218015
On average we null down to the same -94 dB levels. If you listen to the difference signal, at extreme amplification, you can barely here tiny regular noise pumping. This is an artifact of the matching I believe than any audible difference. You are welcome to perform an ABX test as I can share the files here due to kind permission from the band: [youtube comment]
"Missing Film" is a selection of instrumental music I've written and recorded over the past two years. These tracks range from film and TV commissions that didn't pan out, to one-off experiments that have no home. Instead of letting these just sit idly on harddrives, I thought I would make these tracks available to film makers to use, royalty-free, in any of their personal work. So as long as it's non-commercial, you can use any of these tracks for your work and do not need my explicit permission. "
I chose to purchase the album though through bandcamp and I suggest you do the same: https://radicalface.bandcamp.com/album/missing-film
You can pay whatever you choose. Anyway, here are the clips and difference file:
Radical Face Hunted:
Generic AC Cable: https://www.dropbox.com/s/gj74weg67t2bwkh/Radical Face Hunted Generic AC Cord.wav?dl=0
GR Research B24: https://www.dropbox.com/s/7pft7ci37d4rbbj/Radical Face Hunted GR Research B24.wav?dl=0
Difference: https://www.dropbox.com/s/tpg17rdfjr1g5co/Radical Face Hunted Difference.wav?dl=0
I grabbed another track, I'll Be There Soon from same album which has different instrumentation:
View attachment 218016
This one nulled nicely and all that is there is noise even if you turn up the gain some 60 dB.
Here are the tracks again: Radical Face: Missing Film - I'll be there soon
Generic AC Cable: https://www.dropbox.com/s/v5dxg23j6rfeba3/Radical Face I'll be there soon Generic AC.wav?dl=0
GR Research B24: https://www.dropbox.com/s/33l12ajgaiphe8m/Radical Face I'll be there soon GR Research B24 AC.wav?dl=0
Difference: https://www.dropbox.com/s/ys5lva8w9bqghzl/Radical Face I'll be there soon Difference.wav?dl=0
Dropbox can play these files in place so you don't even need to download them. Just click on the links and play them in the new window.
Note that the tracks I picked above are some of my references for testing and enjoyment. They are superbly recorded and any difference in fidelity, should be obvious. There was none in my listening.
GR Research B24 Measurements
Company talks about how their cord "filters" other noise. Since your electronics performs strong filtering of its own, such a thing is not material. But for grins, I tested the worst case of treating the AC cable as an interconnect and putting a powered transformer right next to the cable:
View attachment 218018
The GR research B24 is indeed less receptive to AC noise inducement. As shown though in green line, even if you used any of these AC cord as an audio interconnect, their noise still be inaudible!!! Of course, when used as a power cord, such induction will be beneficial as you would get tiny amount of extra power for free.
We don't listen to power cables directly though so let's plug them into Topping A90 Discrete again and see if its performance changes. Let's start with frequency response to detect tonality changes:
View attachment 218019
None is there. While not shown, the result was the same with the other two power cords mentioned early in the review. I next ran our dashboard:
View attachment 218020
As expected, there is no change whatsoever. Performance is superb whether I use a cheap generic cable or B24. Before someone complains above is at one frequency, let's test at many and include ultrasonics in there as well:
View attachment 218021
There is not even a hair difference. Noise+distortion is below threshold of hearing even though we measure it out to 90 kHz.
Finally as a simulate of "music," let's test with 32 tones:
View attachment 218022
There is not even a slightest difference anywhere in any part of the spectrum with respect to noise or distortion.
I should say that my environment is quite "dirty." I have a workstation running these tests, an Audio Precision analyzer "polluting" the AC with its switching power supply. Half a dozen other devices from network switch to monitor and LED lamp is plugged in. An unterminated scope probe would show ton of airborne "interference" yet none is remotely impacting our audio device. Your situation in an audio system devoid of all the complexity of my system will be far less of a stress test.
Conclusions
We can naturally demonstrate through measurements that a monster heavy cable comprised of 24 individual cables does have lower resistance. And the weave is more resistance to AC noise pick up. As I keep saying though, we don't listen to AC cables, we listen to audio systems. Objective capture and nulling of the output shows zero difference brought to the table by the B24 cable. I have show three tracks. I am confident I can show you any number you want. Result will be the same. Sighted listening can yield "differences" but that can point to generic cable being "better" as well as the B24 depending on order, mood, amount of concentration, etc. Blind test will show no difference because we know objectively there is no difference (because of the null).
Of course as usual, our measurements of the output of the device show identical performance as well. In the past, I have pumped heavily distorted AC waveform into audio devices with no impact on them whatsoever. What hope is there that any "filtering" of an AC cable will make any difference? It can't and it won't.
Beyond lack of improvement on fidelity of the system, I am super disappointed by the build of this cable. It is just awful and I am not talking about the massive weight and stress it puts on your equipment and wall outlet. But rather the poor build of the male plug that works so hard against you being able to perform the simple test of just plugging it in! In that regard, I put any of the brand name AC cable products way, way ahead of GR Research work here. This is poorly done hobbyist work that has not stood the test of any independent evaluation.
While sadly a norm in aftermarket AC cables, the B24 lacks any safety testing. Who knows how safely they have stuff so many wires into its terminations. Who knows what happens if there is a short in your equipment and stress is put on this cable to trip your breaker.
Bottom line, I see no redeeming quality in GR Research B24 AC cable and so cannot recommend it.
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As always, questions, comments, recommendations, etc. are welcome.
Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
This is not just a waste of money. I think it will damage your US wall socket. In addition to the oversized earth pin, surely the weight of such a cable sticking out horizontally will apply a lot of leverage? In the UK, a cable exits vertically downwards from a BS 1363 plug plugged into a wall socket, so there would be no such leverage; is there a variant of the US plug that allows that?
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AudioSceptic
Major Contributor
WTF! That thing looks like a garden hose.Thanks Amir! Interesting, as always with your tests.
What is it called in English, not to walk around the bush? Beat the bush? Never mind what I mean is that it was a test that was straight to the point. Good work!
By the way Amir's arguments, test results vs what the manufacturer Danny at GR Research says about his power cord:
Edit:
Lol, now I know the counter-argument against you Amir not noticing any difference. 5:30 in the video. The power cord needs to be burned in for at least 200 hours before you can start hearing how good it sounds with it.
My God, how much waffle in Danny's video.
AudioSceptic
Major Contributor
That was quick! Yes, thanks. Surely garden hose-size cables like this one should come with plugs like that as standard?
The problem is the commen sense, not the missing of it.
Electricity, and with that electronic has not much to do with commen sense.
But commen sense tells people that if its thiker and more expensive its the better
garden hose.
AudioSceptic
Major Contributor
The previous 15 A and 5 A round-pin plugs also had a longer earth pin. There was no shutter, but doesn't it make obvious sense to connect the earth pin first anyway?We “don’t beat around the bush” in the UK - presumably it’s origin is something to do with hunting and driving fowl out of the undergrowth by hitting the said bush
The UK three pin plug has an overlong earth pin that opens shutters on the socket for the live / neutral pins - it’s a safely feature . I wonder if GC was trying to emulate this!
I really dislike heavy cables , especially signal cables . As you say , the mechanical strain they put on connectors is crazy. But hey - if it helps sell cable lifters so be it
AudioSceptic
Major Contributor
Isn't the U shape a simple way to save metal (and money) whilst still allowing good contact? It will also allow a bit of compliance.
It wasn't magic, it was science. Smelting dramatically changed human civilisation, and whereas copper and bronze were cast, by heating and reworking iron they realised it became much stronger and lighter.If so, it's been around for far longer than hifi gear has been (indeed predating electricity itself).
Although I certainly can't prove it, I'm reasonably sure there was a cave-dwelling ancestor of ours that convinced a neighbor that his rock tools were substantially different and better than anyone else's... because magic! And hey... if you can get 3 mammoth skins for the exact same thing someone else is giving away for free... who's the real fool there?
What does surprise me, whether you believe cables make a difference or not, is that with all the technology we have, some manufacturers of plugs and receptacles are unable to make a basic component that can be guaranteed to stay in place and not break.
Never mind what cables I use, I have spoken to a local supplier who is the largest independent online retailer of such products in UK and also sells into the EU. Their financials are online and it is a fairly large and growing business. They tell me demand is only increasing for power products generally. One reason may be because in Covid due to the lack of retail many more businesses did loans or sale and return, and in the UK it costs $10 to return a cable, not $40. It costs me nothing because I use a local dealer who will loan me anything based on trust and he will normally drop it off personally.
KxDx
Senior Member
They need to have it explained that their bloated bass is from room modes, and a Umik ($100 US), REW (free) and software or hardware EQ will go a hell of a lot father than fancypants cables.
Even if it seems like an uphill battle, we have to remember that newbies are more susceptible because they want improvements that take minimal time and effort, and that's what snake oil salesmen prey upon.
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