Pavel, not sure how it works where you are, but around here the AC power line is earthed and connected to many designs' chassis.
Interesting cable blurb in Audio eXpress...
You certainly can run your own tests. I have been reviewing this with a few folks and the issue seems to be related to very very low level signals.
Now as to "refereed controlled reports" these are measurements, not listening tests. A fair number of folks have stopped by and seen the results. There are a few other reports some using similar techniques.
Now I think there is adequate information to avoid the issues, if you recognize them.
JN
Apparently beauty is only skin deep, stupid runs deeper. You or I would have used a boost/buck transformer, they weren't beautiful either.
They don't show up in any search using related terms. The comment you posted spent most of it's time talking about cleaning connections and was non-commital about any other claims.
If there was a claim presented in a way that it could be independently verified it might be worth some effort. I have learned that around here claims stand no matter how they are supported. I just saw a wire manu today attributing DA to the magnetic field surrounding the wire.
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Try the actual thread that cite referenced. Of course if you are ever in the neighborhood, let me know I'll dust the gizmo off and you can play.
Ugly runs to the bone..
It gets more interesting when you need to convert a 3 phase to 6 phase or 12.
I give up on that vector rotation notation..
jn
Not much info there and I cant find the Audio express article...
But as with solder joints if these things were real phenomena to be concerned with other fields of electronic design would have picked up on them and there would be a whole range of articles regarding directivity in metal based electrical signal paths) its unfair just to pick on cables) and there isn't, despite searching, apart from audio related mostly hearsay.
I would be interested in the solder joint stuff, I wont say they are not problematic, I have worked on a big project regarding lead free component finishes, solder joints and reliability for military applications and don't remember any issues with distortions with a well made joint with the right finishes and intermetallic layers present in the joint (confirmed by micro sectioning etc), bad joints being a different ball game obviously.
But with cable directivity I think its definitely Myth Busted....
But as with solder joints if these things were real phenomena to be concerned with other fields of electronic design would have picked up on them and there would be a whole range of articles regarding directivity in metal based electrical signal paths
) its unfair just to pick on cables) and there isn't, despite searching, apart from audio related mostly hearsay.I would be interested in the solder joint stuff, I wont say they are not problematic, I have worked on a big project regarding lead free component finishes, solder joints and reliability for military applications and don't remember any issues with distortions with a well made joint with the right finishes and intermetallic layers present in the joint (confirmed by micro sectioning etc), bad joints being a different ball game obviously.
But with cable directivity I think its definitely Myth Busted....
Once a long time a go when I was in retail about 29 year ago I had a geologist tell me the cables where directional and wanted only unused ones because if signal was run through them backwords they where ruined . I inquired how does one determine the direction of the cables without testing . I was told it was the way the print ran.Not much info there and I cant find the Audio express article...
But as with solder joints if these things were real phenomena to be concerned with other fields of electronic design would have picked up on them and there would be a whole range of articles regarding directivity in metal based electrical signal paths
I would be interested in the solder joint stuff, I wont say they are not problematic, I have worked on a big project regarding lead free component finishes, solder joints and reliability for military applications and don't remember any issues with distortions with a well made joint with the right finishes and intermetallic layers present in the joint (confirmed by micro sectioning etc), bad joints being a different ball game obviously.
But with cable directivity I think its definitely Myth Busted....
After asking the maker about how the printing was applied he told me when the finished cable come in from the plant they print what ever you want on it off the big spool to the little spools . Usually the print wheel runs right to left not left to right.
Moral of story snake oil that is back words and not audible but very important to some audiophile.
Once a long time a go when I was in retail about 29 year ago I had a geologist tell me the cables where directional and wanted only unused ones because if signal was run through them backwords they where ruined . I inquired how does one determine the direction of the cables without testing . I was told it was the way the print ran.
After asking the maker about how the printing was applied he told me when the finished cable come in from the plant they print what ever you want on it off the big spool to the little spools . Usually the print wheel runs right to left not left to right.
Moral of story snake oil that is back words and not audible but very important to some audiophile.
Well I think it has been mentioned before that at a certain point in time people realised that ground currents could induce hum etc in de cable. That lead to cables that had two conductors for signal hot and cold, plus a screen that was only connected at one side. The screen was to prevent RFI etc, but to avoid ground currents it was only connected at one side.
As it was believed that best results were reached with the screen connection at the source (low impedance) side, they put an arrow on the cable to indicate which side had to be on the source and which side on the receiving end.
Interestingly, if the screening would be less effective with the cable 'wrong way around', this could cause audible differences due to increased RFI.
Unfortunately, the marketing was picked up by the ignoranti and con men leading to 'directional' cables without the original sensible construction.
Jan
I read it again last night, and have not changed my opinion. The huge mains related noise floor has no reason to be there and there is no evidence that mains harmonics out to the frequencies of interest are not contaminating the measurement. I'm sure PMA and jn have seen the spray of mains harmonics extend to 3kHz and beyond, we certainly have in our lab.
Ed, I think Samuel Groner has made his thesis work available if you want to see how far one can go to remove the unwanted confounders, nada down to ~-155dB noise floor (don't know the FFT size).
And BTW he found 3 capacitors, LCR Components -153.4dB, Vishay Roderstein MKP polypropylene nothing at all, and even a Vishay C0G/NPO at -142.5dB so I don't know why anyone couldn't find a suitable commercial cap for just about anything.
The MKP is particularly impressive maybe even reach the -160db level.
EDIT - Wow they cost all of $1-$2 or so.
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hybrid grounding has even reached audio http://www.greendotaudio.com/HTMLobj-1160/FXX-EMC.pdf
A part used as it was designed to as well as and it work . Not sure how well the audiophiles will take that.
As best I could figure out.... the issue of cable directivity was reported as heard when cable was switched end for end. And, the sound was consistant depending on 'direction'. Some cables - but not all - came with errow on them to mark which end was source and load.
It was because the cable (many of them) had a ground (shield or wire) connected at one end only.
THx-RNMarsh
It was because the cable (many of them) had a ground (shield or wire) connected at one end only.
THx-RNMarsh
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