Markw4 we will not ever to prove anything to you, because we START with the phenomenon and work backward to figure out WHY 'wire' for example could possibly make a difference. You want for us to PROVE that an ABX test can be made that shows a subtle difference like low level IM distortion can be identified. The problem is that the ABX test covers the problem up, due to the nature of the test, so almost everything that we have found important in quality audio is almost not identifiable. I would have retired almost 40 years ago, IF I believed in ABX tests. I can't pass them either.
Actually, I am pretty open minded and have been convinced of things based on experimental evidence. However, I am not persuaded by what is so far an unsupported claim that ABX testing covers the problem up. Is there some evidence for that you would like to point to?
I am using WBT RCA Nextgen connectors with a real very audible sound quality improvement. I see that I can expect connectors blackening in a few years. It is hard to believe that WBT made such a fatal construction mistake.This RCA Crap Connector story seems to be a never ending problem.
But Lemo Connectors were and are to expensive for audio, and XLRs are studio grade, thus not for audio.
Had hargold plated RCA s from WBT, veeeeeeeeeery expensive, missed the nickel barrier, they were black after a few years, soem ohms resistance ...
So i learned to avoid any connector when possible and every solder joint alone is better than RCAs with many solder joints.
Maybe todays production methods are better, but are RCAs are a potential problem source.
my 2 Cents
I hope that you informed them of your findings.
It seems that direct gold plating is impossible. Mr. Curl should expect Tiffany direct gold plating RCA in his Blowtorch to turn into copper oxide in the future.
Some more minimum gold thickness information needed to be non-porous (which allows air to reach the base metal and oxidize it).... oxide free.
https://rj45s.com/Gold_Plating_Problems.html
But there are many more sources regarding minimum gold thickness to be non-porous.
THx-RNMarsh
JBL Master Reference Monitor (M2) will be here Tuesday morning.
Crating up my ESL989's for shipping to Bangkok place.
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https://rj45s.com/Gold_Plating_Problems.html
But there are many more sources regarding minimum gold thickness to be non-porous.
THx-RNMarsh
JBL Master Reference Monitor (M2) will be here Tuesday morning.
Crating up my ESL989's for shipping to Bangkok place.
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No, kamis, my direct plated Tiffany RCA connectors still look just fine after more than 25 years. I just checked this carefully 2 weeks ago with a set of connectors from the old days. However, I have had some cheaper Mogami RCA connectors that got spotted even after 1 year of sitting in a plastic case. I don't use them anymore.
Markw4, I won't try to convince you of anything. That would be impossible, but Richard Marsh and I have been researching connectors for almost 40 years. Richard has even contributed to a technical article in AUDIO on the subject. We both own and have read through Holm's books on contacts, etc, etc. This is old stuff to us, and we have lots of experience with wire problems and differences. I suggest that you look through one of Holm's textbooks to find out what really goes on in electrical contacts, etc.
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I cleared a bit the mains residues with my measurement setup. Now I can go a bit lower with the driving signal level and still resolve the ‘across the cable’ signal.
I utilized the instrumentation amplifier only at it’s X1 gain setting.
I made wav recordings of the ‘across the cable signal’ with generator driving signal levels of 1.0015Vrms, 99.88mVrms, 11.42mVrms and 3.89mVrms.
For each signal level, there is one folder that contains 6 recordings of 1 minute duration (three ‘Normal’, three ‘Reversed’) plus some level reference recordings.
There is also one folder containing the generator driving signals.
The wav. files are sampled as mono, 44100Hz, 32bit float.
The 0dB of these recordings corresponds to 3.02Vrms
The test tone is 3001.19Hz. This is a center FFT bin frequency for the standard FFTsizes of 16384 (included) and up, where you can use the No Window function.
The files will remain at the dropbox for around a week.
You may download them and make your own analysis on them.
Report back here
Driving signal File (4 wav files)
https://www.dropbox.com/sh/rkw7ublsfiqd1fz/AACPh8hsVUXnCRRDbuVMsspWa?dl=0
Test with 4mVrms signal (9 wav files)
https://www.dropbox.com/sh/2bt1m7h1snnssf0/AAD_VItZ0B_k2soDF4ops_8Aa?dl=0
Test with 11mVrms signal (6 wav files)
https://www.dropbox.com/sh/cze1o6z0dbuqog0/AADPS2QDYDslo83SlGAIP4FEa?dl=0
Test with 100mVrms signal (6 wav files)
https://www.dropbox.com/sh/ai7cme1yl1y5fzp/AACQvLq_w_jpsEnh5-9R9l1ca?dl=0
Test with 1000mVrms signal (6 wav files)
https://www.dropbox.com/sh/rxp3bzyja5ncq3b/AAA186TtRkQU26PMA3XTRwnba?dl=0
George
I utilized the instrumentation amplifier only at it’s X1 gain setting.
I made wav recordings of the ‘across the cable signal’ with generator driving signal levels of 1.0015Vrms, 99.88mVrms, 11.42mVrms and 3.89mVrms.
For each signal level, there is one folder that contains 6 recordings of 1 minute duration (three ‘Normal’, three ‘Reversed’) plus some level reference recordings.
There is also one folder containing the generator driving signals.
The wav. files are sampled as mono, 44100Hz, 32bit float.
The 0dB of these recordings corresponds to 3.02Vrms
The test tone is 3001.19Hz. This is a center FFT bin frequency for the standard FFTsizes of 16384 (included) and up, where you can use the No Window function.
The files will remain at the dropbox for around a week.
You may download them and make your own analysis on them.
Report back here
Driving signal File (4 wav files)
https://www.dropbox.com/sh/rkw7ublsfiqd1fz/AACPh8hsVUXnCRRDbuVMsspWa?dl=0
Test with 4mVrms signal (9 wav files)
https://www.dropbox.com/sh/2bt1m7h1snnssf0/AAD_VItZ0B_k2soDF4ops_8Aa?dl=0
Test with 11mVrms signal (6 wav files)
https://www.dropbox.com/sh/cze1o6z0dbuqog0/AADPS2QDYDslo83SlGAIP4FEa?dl=0
Test with 100mVrms signal (6 wav files)
https://www.dropbox.com/sh/ai7cme1yl1y5fzp/AACQvLq_w_jpsEnh5-9R9l1ca?dl=0
Test with 1000mVrms signal (6 wav files)
https://www.dropbox.com/sh/rxp3bzyja5ncq3b/AAA186TtRkQU26PMA3XTRwnba?dl=0
George
Attachments
Mark, you don't understand. This is hi end audio. It goes like this:
You listen alternatively to two amps. It is easy to see (!) that they sound different.
Next you set up an ABX* with the same amps and you can no longer hear a difference. Ergo, ABX covers up the differences.
Easy.
Jan
*For some reason, ABX is always used as a wrap of all controlled testing although it is just one type of equipment that can be used for a specific type of controlled testing. But there are many more methods of course.
If so, then what is the minimum difference in amp sounds before it can reliably be heard in ABX? In other words, if people don't like ABX then they should show at what point it fails. For example, I have some fairly high end DACs and can hear the difference. Most neophytes can't hear it though, until I point out what to listen for. Then they start to get better at it. Similar to getting better at discerning musical pitch with some training and practice. So, if you set things up so some of the skeptics can hear a difference between 2 pieces of equipment if they get to switch them back and forth themselves, and fail to be able to tell a difference in ABX, at least some of them should start coming around to your point of view. But so far, it sounds like there is way too much reluctance to make a scientific case you are right. JC says he can never convince me and he won't try. With an attitude like that I can see why some of the skeptics would tend to see him as a crackpot. If he doesn't like being dismissed that way then he can decide if he wants to do something to fix that or continue with the way things are now.
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So how do we know that the ABX switcher system indeed does not cover up differences ???.
Any photos, any schematics available ?.
What are these 'many more methods' ?.
Dan.
I just did a text search of Holmes, Electric Contacts Theory and Applications 4th Ed. The word distortion appears 3 times, once in reference to what seems more like mechanical distortion instead of electrical. Of discussion that applies to electrical, some of it appears to have been done with crystalography, a pretty old and limited methodology for probably most purposes including the issue at hand. There is also some reference to tunneling.
My interpretation of what I have read so far is that you can have various problems with connectors, which I think we know already, but I don't see any evidence in the book that what they are saying applies to directionality inside of wires.
And I don't know why proper gold plating or proper contact wiping would not be sufficient to address what is known about connectors and contacts for audio use. Looking at the book has not convinced me otherwise.
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I think you sum it up nicely. As they say, if your well-being or your income depends on not knowing something, no way you will want to learn it!
I have gotten myself a Van Alstine ABX box and have been playing with it, on and off, for a few months now. Two experiences stand out:
1 - in several cases, where I could not hear a difference between amps in casual, sighted comparisons, I found that I DID hear differences, repeatably so, when switching rapidly between them with the ABX in blind test mode! Exactly the opposite as what I was made to believe!
2 - the complaint that blind testing is stressful is true. Especially in the beginning, I felt pretty uncomfortable when doing comparisons without knowing which is which. I attribute that to the fact that we are so used to integrate all our sensory inputs and combine them with experiences and beliefs, to form an opinion, that it feels quite unnatural to do it with everything shut off except the ears.
You get used to it over time, and you learn to accept it as just another mode of operation.
But in the initial learning period, when you are getting to grips with it, it may well be that you miss non-subtle audible differences that are really there.
Jan
What you describe is about what I would expect. Recognition is almost entirely a System 1 brain process that operates outside of conscious awareness. When you recognize a face, you automatically recognize the person if you know them. You don't consciously compare things like the ration of the length of the nose to the spacing of the eyebrows to work it out like a math problem. When you relax and let a trained System 1 work, it works far better for sensory recognition purposes than thinking about it consciously (a System 2 process) ever could. This is a lot of why ABX testing should be able to provide good statistical results for detecting a very small signal (or distortion) buried in noise.
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I have an alternative explanation. You hear with your ears AND your eyes. Remove one of those two senses and you have problems.
I have an alternative explanation. You hear with your ears AND your eyes. Remove one of those two senses and you have problems.
Of course. That post of mine was tongue-in-cheek/sarcastic. I hope that was clear
Jan
Quite right. Reminds me of that testing Harman Kardon did on speakers. They started with sighted listening to judge the bass performance of several speakers. Their own speaker designers also participated and were warned to try to be as objective as possible. They laughed - hey, we are speaker designers, we do this for a living, we KNOW just to judge the sound.
But, to their chagrin, reality was tripping them up. When the test was repeated double blind, it was found that in sighted listening, the box size was more correlated with bass quality, than in the double blind case. Even from the speaker designers.
Jan
I thought of an automobile analogy, but decided on this one instead:-
You hear a woman's voice (speaking). It sounds beautiful. Then she walks around the corner and she's a real dog.
A wave of disappointment sweeps over you.
Now, reimagine that when she walks around the corner, she's actually a real stunner. Totally different emotion rolls over you. Do you get your tape measure out (ok - no dirty jokes here) or do you just enjoy the vision and the sound?
There's a third narrative here. You've never heard her, but your friend tells you she sounds wonderful . . .
That's how it is with audio my friends.
If it looks good and it sounds good go figure.
You hear a woman's voice (speaking). It sounds beautiful. Then she walks around the corner and she's a real dog.
A wave of disappointment sweeps over you.
Now, reimagine that when she walks around the corner, she's actually a real stunner. Totally different emotion rolls over you. Do you get your tape measure out (ok - no dirty jokes here) or do you just enjoy the vision and the sound?
There's a third narrative here. You've never heard her, but your friend tells you she sounds wonderful . . .
That's how it is with audio my friends.
If it looks good and it sounds good go figure.
Of course. That post of mine was tongue-in-cheek/sarcastic. I hope that was clear
Jan
Of course
I thought of an automobile analogy, but decided on this one instead:-
You hear a woman's voice (speaking). It sounds beautiful. Then she walks around the corner and she's a real dog.
A wave of disappointment sweeps over you.
Now, reimagine that when she walks around the corner, she's actually a real stunner. Totally different emotion rolls over you. Do you get your tape measure out (ok - no dirty jokes here) or do you just enjoy the vision and the sound?
There's a third narrative here. You've never heard her, but your friend tells you she sounds wonderful . . .
That's how it is with audio my friends.
If it looks good and it sounds good go figure.
That's easy -- it's subjective. In your analogy, not everyone would agree on the best voice, or the best looks, or the best combination. That's no bad thing, in fact it makes life far more interesting. It only becomes an issue if one person claims that their lovely woman with the good voice is actually the best, and you are wrong..... Or tries to justify same with some pseudoscience! Vive la difference!
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