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GR Research B24 AC Cord Review

Rate this AC Cable

  • 1. Waste of money (piggy bank panther)

    Votes: 371 95.6%
  • 2. Not terrible (postman panther)

    Votes: 4 1.0%
  • 3. Fine (happy panther

    Votes: 1 0.3%
  • 4. Great (golfing panther)

    Votes: 12 3.1%

  • Total voters
    388

tomchr

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Do you want a link to the Fielder papers? Is that what would make you happy? He has provided it at least once. I could did up for you again.
All I was after was a mention ON THE GRAPH of where the threshold of audibility came from. One bloody footnote. That is all. It is fundamental scientific communication to cite your sources. Is that too much to ask of Audio Science Review?

Tom
 

tiramisu

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Not ever having been an audiophile I never realized how much complete bullshit there is in the audio forums/youtube/etc. I have been spending a fair amount of time reading recently and the amount of ignorance and outright lying is stunning. It is a complete mess. Magic cables, magic tubes, magic chips, magic speakers, DACS, and AMPS are said to sound different without any audible differences described simultaneously as warm, neutral, analytical, and muddy. Manufacturers, sellers, and consumers all equally promote this pile of stinking dung. Really wtf? Meanwhile, manufacturers ignore basic things like having enough voltage to drive their IO and can't manage to make gear that doesn't break a day after shipping and charge extra for lossy compression. Obviously and happily there are exceptions, but you have to do a lot of digging to find the ones that aren't completely full of shit.
 

Doodski

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Not ever having been an audiophile I never realized how much complete bullshit there is in the audio forums/youtube/etc. I have been spending a fair amount of time reading recently and the amount of ignorance and outright lying is stunning. It is a complete mess. Magic cables, magic tubes, magic chips, magic speakers, DACS, and AMPS are said to sound different without any audible differences described simultaneously as warm, neutral, analytical, and muddy. Manufacturers, sellers, and consumers all equally promote this pile of stinking dung. Really wtf? Meanwhile, manufacturers ignore basic things like having enough voltage to drive their IO and can't manage to make gear that doesn't break a day after shipping and charge extra for lossy compression. Obviously and happily there are exceptions, but you have to do a lot of digging to find the ones that aren't completely full of shit.
You know it brother! The amount of smoke and mirrors is thick
 

tomchr

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And that's why measurements matter.

Tom
 
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amirm

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All I was after was a mention ON THE GRAPH of where the threshold of audibility came from. One bloody footnote. That is all. It is fundamental scientific communication to cite your sources. Is that too much to ask of Audio Science Review?

Tom
How many thresholds of hearing you know about?
 

tomchr

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At least three. How's that relevant? My point regarding scientific communication still stands. Is it too much to add a '[n]' next to "Threshold of hearing" and [n]: Lastname, I. (Year) Title of Paper, Title of Journal. I bet it would take less time than it took to add the curve and other annotation to the graph.

I would expect an undergraduate student in a psychology (or any other science) program to do this (or they could be accused of plagiarism) and I think it's reasonable to hold you to a higher standard than an undergraduate student. Not that there's anything wrong with being an undergraduate student... :)

Tom
 
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I would expect an undergraduate student in a psychology (or any other science) program to do this (or they could be accused of plagiarism) and I think it's reasonable to hold you to a higher standard than an undergraduate student. Not that there's anything wrong with being an undergraduate student... :)
What good would that do you? I have since provided the reference multiple times. Yet it is clear that you won't read them and only aim to complain.
 

dav0043

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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.

Edit: video review posted as well:


-----------
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/
We all know that cables dont matter. Lets move on, shall we?
 
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amirm

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We all know that cables dont matter. Lets move on, shall we?
Nope. I will keep testing them as they come my way. The work isn't aimed at people who believe. But those who don't.
 

dav0043

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At least three. How's that relevant? My point regarding scientific communication still stands. Is it too much to add a '[n]' next to "Threshold of hearing" and [n]: Lastname, I. (Year) Title of Paper, Title of Journal. I bet it would take less time than it took to add the curve and other annotation to the graph.

I would expect an undergraduate student in a psychology (or any other science) program to do this (or they could be accused of plagiarism) and I think it's reasonable to hold you to a higher standard than an undergraduate student. Not that there's anything wrong with being an undergraduate student... :)

Tom
Ability to pay for tuition and ability to have a fragment of a clue are mutually exclusive. You've managed to assemble enough money. Let's leave it at that.
 

Biagiod

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At least three. How's that relevant? My point regarding scientific communication still stands. Is it too much to add a '[n]' next to "Threshold of hearing" and [n]: Lastname, I. (Year) Title of Paper, Title of Journal. I bet it would take less time than it took to add the curve and other annotation to the graph.

I would expect an undergraduate student in a psychology (or any other science) program to do this (or they could be accused of plagiarism) and I think it's reasonable to hold you to a higher standard than an undergraduate student. Not that there's anything wrong with being an undergraduate student... :)

Tom

Tom. You seem to have a real attitude towards Amir and ASR. I have no idea where it comes from but sure your comments go beyond plain good manners.
Granted world is full of people like you who just complain for the sake of it, but sure it is disturbing reading your contentious posts in this forum.

Please, but only if u can, be at least polite. We all owe Amir a lot for all the work is doing

Marco
 

dav0043

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Nope. I will keep testing them as they come my way. The work isn't aimed at people who believe. But those who don't.
Nope. I will keep testing them as they come my way. The work isn't aimed at people who believe. But those who don't.

Nope. I will keep testing them as they come my way. The work isn't aimed at people who believe. But those who don't.
The horse is dead. Beating it is targeting the charlatans that make a profit from belief over science. People that believe don't understand science. Waste of effort. Every cable review will debunk the belief and science supporters will already know that and believers will be unswayed.
 

dav0043

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Nope. I will keep testing them as they come my way. The work isn't aimed at people who believe. But those who don't.
You're assuming there is a cable out there that is worth the money. One review = 1000 reviews. Cables don't matter. People of science already know that.
 

DualTriode

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It does not. Never has, never will. I explained this in my article. How could you continue to disregard information put in front if you? Room noise has a frequency dependent SPL. There is no such one number for it.

I should charge you a consulting fee.

Air velocity noise at air terminals is the primary source of HVAC air flow noise in buildings.

Many times I can walk in and know that there is a problem, often a hand held SPL meter set on the A scale can show if or to what extent there is problematic noise. There is a certain level of desired air flow noise noise in rooms like class rooms. Medical facilities are designed for masking noise for privacy.

Live performance venues are critical for low noise. Often the ducts are installed on the roof to allow the fan noise to escape outside the performance space.

Where sound level performance needs to be documented with calibrated microphone and 8 octave band measurements

The building codes require that the ventilation fans run continuously. This is closely monitored now in the days of Cvid-19.

If you believe otherwise some people may be in harms way.

For Grins:

https://www.titus-hvac.com/file/7562/acoustics_guidelines2018.pdf

Thanks DT
 

BlackTalon

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Sorry for derailing the conversation, but those guidelines have a 2018 date (in the document title at least -- I do not see a date on the actual pages). They reference 'current' ASHRAE Handbook instead of providing the date/ volume -- which is unfortunate when they pull guidelines from it and it is important to know which version it is based on. All 4 Handbook volumes have been updated since 2018. So it's possible some of the info/ guidelines in that Titan publication may have changed slightly. Poor writing on their part. But it's also possible they have a newer version that tracks with the current Handbook volumes. It is still good information, but there is always a danger working with outdated Codes and industry standards.
 
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amirm

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Many times I can walk in and know that there is a problem, often a hand held SPL meter set on the A scale can show if or to what extent there is problematic noise.
Your SPL meter is dumb as a stomp. Industrial noise pollution standards and practices live in dark ages. Audibility of noise must be done per frequency bands or it is useless.
 

tomchr

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I have since provided the reference multiple times. Yet it is clear that you won't read them and only aim to complain.
Yes. Since then. Going forward, whenever you add a reference curve would you please also add a footnote to the graph with a reference to where that curve came from so that those of us who like to get to the bottom of things can? Please. Pretty please?!

Tom. You seem to have a real attitude towards Amir and ASR. I have no idea where it comes from but sure your comments go beyond plain good manners.
Granted world is full of people like you who just complain for the sake of it, but sure it is disturbing reading your contentious posts in this forum.
I admire that you choose to sign up so you could post that.

I'm not complaining for the sake of complaining. I'm complaining because I would like to see more science and less BS. I think most of us here have that in common. I'd like to see the questions by @Lambda in Post #66 answered, for example, because they're relevant here. And I'm also speaking up because I'm just not the type to take whatever Amir (or anyone else) posts as gospel. I think about things and ask questions. Maybe that's my problem.

Please, but only if u can, be at least polite.
Where have I not been polite? Is expressing criticism or critique of a scientific experiment the same as being impolite? Part of the scientific process is peer review and critique. No?

We all owe Amir a lot for all the work is doing
And all I'm trying to do is to nudge Amir to do even better work. But it doesn't seem to be well received, so perhaps I should stop.

Getting back on topic: The only case where I think a different power cord could make a difference is if the 'upgrade' power cord is one of heavier gauge wire. In a single-ended system, such as most residential audio systems, that would result in a lower impedance ground between pieces of equipment, which can result in a lower error voltage between different pieces of equipment, thereby lower noise and hum. Bruno Putzeys' article, "The G Word" is a good primer: https://www.edn.com/the-g-word-how-to-get-your-audio-off-the-ground/
But even in that case, it's the wire gauge (cross-sectional area) and possibly the quality of the connectors that matter. Not whatever bling is added to the cord.

Tom
 

Blumlein 88

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Yes. Since then. Going forward, whenever you add a reference curve would you please also add a footnote to the graph with a reference to where that curve came from so that those of us who like to get to the bottom of things can? Please. Pretty please?!


I admire that you choose to sign up so you could post that.

I'm not complaining for the sake of complaining. I'm complaining because I would like to see more science and less BS. I think most of us here have that in common. I'd like to see the questions by @Lambda in Post #66 answered, for example, because they're relevant here. And I'm also speaking up because I'm just not the type to take whatever Amir (or anyone else) posts as gospel. I think about things and ask questions. Maybe that's my problem.


Where have I not been polite? Is expressing criticism or critique of a scientific experiment the same as being impolite? Part of the scientific process is peer review and critique. No?


And all I'm trying to do is to nudge Amir to do even better work. But it doesn't seem to be well received, so perhaps I should stop.

Getting back on topic: The only case where I think a different power cord could make a difference is if the 'upgrade' power cord is one of heavier gauge wire. In a single-ended system, such as most residential audio systems, that would result in a lower impedance ground between pieces of equipment, which can result in a lower error voltage between different pieces of equipment, thereby lower noise and hum. Bruno Putzeys' article, "The G Word" is a good primer: https://www.edn.com/the-g-word-how-to-get-your-audio-off-the-ground/
But even in that case, it's the wire gauge (cross-sectional area) and possibly the quality of the connectors that matter. Not whatever bling is added to the cord.

Tom
Yes, he put an unknown transformer near the cable with unknown field strength.

Years back I've done variation on that. Wrapped interconnects around a high power gaming PC power supply. Was a handy source of noise. Different RCA cables varied in how much they picked up and many were plainly obvious. Unwrap them and just pass by all, but touching and lower though still obvious noise was heard. Move them 6 inches away and nearly nothing visible in low level measurements, with nothing heard. One foot away and there was simply nothing there.

Next wrapped some XLR's around the same supply. Nothing there. Got a longer set of those and wrapped them around the PS several times. Nothing there.

It seemed adequate to realize keep your RCA's a few inches from any possible high level source of noise and nothing to worry about. Use XLR's and definitely things are good.

I suppose the Deltawave results he obtained was plenty to show me there is nothing positive in this cable vs any other cable. Using it as an interconnect, who cares? I looked at it as just a goof to show it also didn't make any difference as a signal carrying wire vs carrying 60/50 hz power.
 
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