| Steve Eddy |
The original thread having been closed (see http://www.diyaudio.com/forums/show...&threadid=23440 ), I'm starting this thread for the discussion of the followup measurements intended to address the concern that John and Bruno hadn't measured the same cables.
To that end, I made up two sets of identical cables. Each set included an old Radio Shack Gold interconnect that I had laying around here which was well used but hadn't been used for at least a couple years. A brand new, unused Radio Shack Gold interconnect. A bog standard giveaway cable which were included with my DishNetwork boxes. And finally, just to add some interest, a cable made up using Manhattan/CDT M4214 which is an RG 174/U type.
The reason I threw this last cable into the mix is because its center conductor (7/34 stranded) is made of copper clad steel.
I figured that if the distortion John is measuring is indeed being produced by the conductors themselves, then using a ferromagnetic conductor such as steel should result in distortion significantly greater than even the most bog standard copper or silver conductors.
Interestingly, of the four cables I sent John, the cable with which he measured the LEAST distortion, was the copper clad steel core RG 174/U.
Here's John's response from the other forum:
Been there, got the cables, measured them.
RS cables are slightly the worst, but not too bad, el cheapo cable came in slightly better, custom 174 came out best. No cable was quite as good as the reference, but not bad.
Signifcantly worse were some cables here already.
The old Radio Shack Gold and the giveaway cable are on their way to Bruno (they were sent the same day that I sent John's cables). The new Radio Shack Gold and the RG 174/U are ready to send to Bruno on Monday.
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| SY |
| I'll be interested in seeing the measurement details, especially repeatability and replicability. Do you know what the "reference" was? |
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| Steve Eddy |
| quote: | Originally posted by SY
Do you know what the "reference" was? |
I think John's still using some model of van den Hul as his reference cable.
se |
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| john curl |
My test frequency is 5KHz and my level is 70mV with a 600ohm source and 2Kparalleled with 50K load.
Let's see first if Bruno can find ANY distortion at all.
Sy, I don't need to be second guessed by Steve Eddy. If you have a question, please ask me.
I have found an expensive VDH video cable terminated with VDH connectors works very well. I have also found that a JPS cable works at least as well, but it is less flexible, so it is more difficult to use on a regular basis. Both cables are shielded 75 ohm types, and both have a distortion residual at about -120dB or better.
Steves cables measure worse than this, by 5 to 10dB typically. |
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| Steve Eddy |
| quote: | Originally posted by john curl
My test frequency is 5KHz and my level is 70mV with a 600ohm source and 2Kparalleled with 50K load. |
Thanks. I'll pass that on to Bruno.
Is 600 ohms the lowest you can go with regard to your source impedance? It would be interesting to measure the RG 174/U cable with as much current as you can manage and at a much lower frequency which would maximize the nonlinearities due to the steel core. What's the maximum level of your 1700B's oscillator?
| quote: | | Let's see first if Bruno can find ANY distortion at all. |
If the cables I sent are in fact producing distortion at -115 to -120 dB relative to the fundamental as you say, then they should stick out like a sore thumb seeing as the System Two Cascade's generator's thrid harmonic residual is at -130 dB and clearly visible on the previous measurements that Bruno made.
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| fdegrove |
Hi,
Anyone care to measure my silver darlings or silver + gold ?
Cheers,;) |
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| Steve Eddy |
| quote: | Originally posted by fdegrove
Anyone care to measure my silver darlings or silver + gold ? |
Well, unless you expect them to have sufficient distortion that it'll show up on the System Two Cascade, I don't see much point.
So far none of the cables Bruno has measured on the System Two Cascade have shown any signs of distortion. That's why I decided to send the steel cored RG 174/U cable in hopes that SOMETHING might be sufficiently nonlinear that it'd be within the System Two Cascade's reach. Can't think of anything worse than copper clad steel that would stand much chance of being used at all for audio cables.
If the RG 174/U doesn't do it, I'll go over to Mills and get some nichrome wire and try that.
se |
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| fdegrove |
Hi,
| quote: | | Well, unless you expect them to have sufficient distortion that it'll show up on the System Two Cascade, I don't see much point. |
I don't, and I KNOW they don't ....
| quote: | | Can't think of anything worse than copper clad steel that would stand much chance of being used at all for audio cables. |
Yes....Good to see you "think" although I'm not sure anything useful will show up.
Cheers,;) |
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| johnferrier |
| quote: | Originally posted by Steve Eddy
...get some nichrome wire and try that. |
So, it's nickel that is "bad"? Just wondering because the Vishay bulk metal foil resistors are nichrome. Steve when I wrote about these before, you mentioned "ruthenium oxide", not having the details that these particular resistors are constructed with nichrome. They are "non-inductive" but I guess they could be magnetic.
JF |
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| Steve Eddy |
| quote: | Originally posted by fdegrove
I don't, and I KNOW they don't .... |
If you KNOW they don't, then perhaps you could send a set to John. If his measurement of them turns up distortion then we would KNOW that the distortion he's been measuring is in fact being produced by his 1700B.
se |
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| Steve Eddy |
| quote: | Originally posted by johnferrier
So, it's nickel that is "bad"? Just wondering because the Vishay bulk metal foil resistors are nichrome. Steve when I wrote about these before, you mentioned "ruthenium oxide", not having the details that these particular resistors are constructed with nichrome. They are "non-inductive" but I guess they could be magnetic. |
Well it's that nickel is ferromagnetic and saturable if the field's strong enough so if you want something that can produce nonlinearities, nickel and nickel alloys should work. Steel would be the poorer choice between the two since it saturates at much higher flux densities.
Not sure what you mean about the Vishays and ruthenium oxide. I don't recall saying the Vishay bulk metal foils were made with ruthenium oxide. I do recall mentioning a while back that ruthenium oxide was typically used for thick film resistors.
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| fdegrove |
Hi,
| quote: | | If you KNOW they don't, then perhaps you could send a set to John. |
Certainly, provided John won't mind...
Those are leads measured in" Belgium" though, is that good enough?
You know it's that same small country that brought you CD, so called French Fries and all that other ****...
Maybe I should bribe you with a ballot of pralines first? :D
Cheers,;) |
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| johnferrier |
| quote: | Originally posted by Steve Eddy
Not sure what you mean about the Vishays and ruthenium oxide. I don't recall saying the Vishay bulk metal foils were made with ruthenium oxide. I do recall mentioning a while back that ruthenium oxide was typically used for thick film resistors.
se |
Okay, guess the thoughts on bulk metal and thick films got intertwined.
Thanks, for clarifying the issue with nickel.
JF |
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| Steve Eddy |
| quote: | Originally posted by fdegrove
Those are leads measured in" Belgium" though, is that good enough? |
Good enough for what?
| quote: | | Maybe I should bribe you with a ballot of pralines first? :D |
Pralines? Yeccch. Try some nice unadulterated Belgian chocolate. Been havin' a hankerin' for some truffles lately.
se |
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| Steve Eddy |
| quote: | Originally posted by johnferrier
Okay, guess the thoughts on bulk metal and thick films got intertwined. |
I looked up the post. Here it is:
http://www.diyaudio.com/forums/show...2096#post282096
My mention of ruthenium oxide was in response to a link you'd given to an article about why Vishsay bulk metal foils were superior to carbon comp and thick film resistors and you'd made note of the bit in the article as to why carbon comps and thick films were noisier than the bulk metal foils and thought perhaps that could explain the "microdiode" theory.
I was pointing out that the situation with carbon comps and thick film resistors wasn't the same as you'd have with copper wire. In fact the reason the situation wouldn't be the same with copper is the same reason the bulk metal foils aren't as noisy.
| quote: | | Thanks, for clarifying the issue with nickel. |
No problem.
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| fdegrove |
Hi,
| quote: | | Been havin' a hankerin' for some truffles lately. |
That's what we've trying to tell you for a year...
Cheers,;) |
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| john curl |
Frank, please quit putting your foot into this.
First, we have to see if we are measuring anything at all.
Steve implicitly trusts Bruno, because Bruno is getting null results.
I don't get nulls as often, so my test system is suspect.
Up to this point, I believe in my testing, but I am not interested in further measurements for people on this website, in general.
Furthermore, I don't care what Steve Eddy wants. He is no friend or even competitor of mine. My competitors and I treat each other with dignity, and we even help each other, on occasion.
He, and he alone, brings this subject of wire distortion, continually. If he can 'trash me' he will do so, big time.
I did my tests because I thought they showed something interesting about cables. I even invested in better test equipment, after being ridiculed at first, for my 'Mac the Scope' printouts. I cannot justify a $30,000 rig, just to please Steve Eddy, or any of the rest of you. Get your own test equipment, or leave it be. |
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| SY |
Well, I'm interested in Bruno's measurements, too, because he's doing it on a system with better resolution than yours and enormously better than mine. And he seems to understand the need for documenting the gauge R&R capabilities of the system.
I'm also not a competitor, nor in the hifi business in any capacity, but having a pretty strong background in the physics of conductive materials, I'd sure like to see some interesting new phenomena to study. But they have to be REAL phenomena, not measurement artifacts- I learned well my lesson from Stan Pons.
If I were going to add one more thing to the list of test candidates, it would be some coathanger wire with the ends scraped free of insulation. That seems to be the favorite whipping boy of the magic cable set ("No more wire hangers! No more wire hangers!" "Owwww! No! Mommy!"). |
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| Steve Eddy |
| quote: | Originally posted by john curl
First, we have to see if we are measuring anything at all. |
Yes. Which is why I've so far spent over $50 of my own money on cables and postage so that you and Bruno can have the same cables to measure.
| quote: | | Steve implicitly trusts Bruno, because Bruno is getting null results. |
I implicitly trust no one and have always kept open the possibility that Bruno is being dishonest.
However I am more inclinded to trust the measurements made on a modern, reference standard measurement system known to be capable of measuring well below the levels you claim to be measuring.
| quote: | | I don't get nulls as often, so my test system is suspect. |
Your test system is suspect because if simple wires were as grossly nonlinear as your measurements indicate, not only is it difficult to believe that this behavior would have completely escaped the notice of the materials science research community, but it would render wire absolutely useless in applications where it's been working just fine for many decades.
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| kamskoma |
About test equipment, can I use a simple THD analyzer like the HP 332A to null out the fundamentals and put this signal into a soundcard like the DAL CardDeLuxe togetherwith a good FFT software, is this a good measurement device?.
What I think is, it may be very simple to make a reference measurement that will go for all comming measurements or?
Just measure the nulling device with a good soundcard Card DeLuxe then you have a very good an cheap instrument.
If not! where is the fault, and can I do it with even cheaper nulling device and soundcards. |
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| john curl |
Sy, I will tell you this:
I am making a series of fairly difficult measurements with the test equipment that I have. My ST was designed to work to approximiately -100dB, at measurement levels about .3V or more. With added FFT processing, I can separate the harmonics from the null residue and reduce the noise floor.
I CAN produce measurement artifacts, if I am not careful. For example, if I load the oscillator buffer excessively, I can begin to produce extra 2'nd and 3'rd harmonic distortion. However, when I find a 'clear' area of measurement, then I can make measurement comparisons.
Once I have a measurement set-up that seems OK with my reference cables, I make NO changes to the measurement equipment. I just change the cable by removing it from the connector and replacing it with another.
At this point, I can see differences between different cables, both of different lengths and the same length. I can also see differences with similar cables, but with different use patterns, such as the amount of signal passed through them over time.
I can also see minor distortion 'bumps' build up, if my reference cable's connectors and the the whole external assembly are not periodically cleaned with industrial purity isopropyl alcohol The 'bumps' go down or away, after cleaning.
I monitor the input of the analyzer with a 350MHz Tek 485 scope, running maximum bandwidth, given the test conditions. I see no oscillation on the scope.
At this point I can do no more to show anything.
If Bruno's results are again a null, then the comparison is ended. |
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| SY |
John, thanks for the additional details.
This may be asking a lot, and I won't at all take offense at a "no" answer (nor draw any inferences; lots of people just like their privacy), but would it be possible for you to demonstrate for me how the measurement is done? I'd like to do an informal gauge R&R by connecting and disconnecting the same cable, playing around with the dress of the cable, and so forth.
As I said, my own professional expertise is the physics of conductive materials, and coincidently, fourier transform techniques (I was the #2 guy in R&D at Nicolet back when they were the Big Guys in FFT instrumentation, which certainly dates me!). So this really seems to be up my alley. I've got no axes to grind, I just want to understand your measurements and what they really mean.
As recompense for your time, I'll happily cart along a bottle of something rare and vinous. |
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| kamskoma |
One person I like to see participate here is Siegfried Linkwitz he was the BIG GUY who constructed FFT monsters at HP a very nice technician that can sweeping the fog away.
Another good techie Nelson Pass I will remember that he made a measure on cables years ago maybe this can be used as a reference here. |
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| Steve Eddy |
| quote: | Originally posted by kamskoma
About test equipment, can I use a simple THD analyzer like the HP 332A to null out the fundamentals and put this signal into a soundcard like the DAL CardDeLuxe togetherwith a good FFT software, is this a good measurement device?. |
Well, the graphs of the measurements John did some time ago were done by feeding the residual from his 1700B into the built in sound card in his Macintosh using a demo version of Mac The Scope software.
| quote: | What I think is, it may be very simple to make a reference measurement that will go for all comming measurements or?
Just measure the nulling device with a good soundcard Card DeLuxe then you have a very good an cheap instrument.
If not! where is the fault, and can I do it with even cheaper nulling device and soundcards. |
The issue here isn't determining whether John is measuring distortion or not. He clearly is. The issue is whether the distortion he's measuring is in fact being produced by the cables or by his 1700B.
So far, using a system known to have lower distortion and greater resolution than what John's using, none of the high order distortion products that John routinely measures have shown up. John says he measures distortion with virtually every cable he's used, but even when measuring a good 20dB below where John's measuring, nothing has turned up.
The measurements that Bruno did had been dismissed by someone else because Bruno wasn't measuring the same cables as John. So this is an attempt to repeat the measurements with both John and Bruno measuring the same cables.
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| Steve Eddy |
| quote: | Originally posted by kamskoma
One person I like to see participate here is Siegfried Linkwitz he was the BIG GUY who constructed FFT monsters at HP a very nice technician that can sweeping the fog away.
Another good techie Nelson Pass I will remember that he made a measure on cables years ago maybe this can be used as a reference here. |
If you think you can interest either of these gentlemen in doing low level distortion measurements on cables, that would be a plus. I know Nelson has an AP rig.
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| millwood |
| quote: | Originally posted by john curl
Frank, please quit putting your foot into this. |
ouch!
| quote: | Originally posted by SY
(I was the #2 guy in R&D at Nicolet back when they were the Big Guys in FFT instrumentation, which certainly dates me!). |
Wow! we have some seriesly knowledgeable folks here.
| quote: | Originally posted by Steve Eddy
Well, the graphs of the measurements John did some time ago were done by feeding the residual from his 1700B into the built in sound card in his Macintosh using a demo version of Mac The Scope software.
se |
I didn't follow this thread as closely but two things here:
1) did John repeat the tests? maybe the sound card is faulty the time John was testing it?
2) did the distortion come from the source? what if John used a very short or better cable? Would John have seen anything materially different?
I think we are certainly making progress here, from anecdotes to concrete measurements. Keep up the good work, folks. |
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| SY |
| quote: | | Wow! we have some seriesly knowledgeable folks here. |
Not compared to the #1 guy there at the time, a spooky-smart Cajun named Warren Vidrine. I was seriously lucky to be able to get a job working for him, and I've even forgiven him for introducing me to my first wife. We're still close friends, even after all these years (damn, was that really 20 years ago?!).
It's sobering for me to realize how sophisticated the stuff we were doing then seemed to be, yet it's all trivially easy these days with PCs and modern software. |
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| millwood |
| quote: | Originally posted by SY
It's sobering for me to realize how sophisticated the stuff we were doing then seemed to be, yet it's all trivially easy these days with PCs and modern software. |
yeah. it is just that much easier to implement FFT in software than hardware, :).
Thank God for data acquisition and computers, :) |
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| john curl |
| Kam, the HP 332 probably won't do it, BUT the HP339 should be OK. It is just a matter of distortion residual. I have enough problems, you would not not want to use something even older and compromised as far as residual distortion is concerned. |
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| john curl |
| Kam, the HP 332 probably won't do it, BUT the HP339 should be OK. It is just a matter of distortion residual. I have enough problems, you would not not want to use something even older and compromised as far as residual distortion is concerned. |
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| Steve Eddy |
Is there an echo in here?
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| john curl |
| Accidents happen, keep on target. |
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| Charles Hansen |
Hello -
I haven't been following this whole thing very well, but if I understand correctly, you are trying to have somebody in Europe verify John Curl's cable measurements with an Audio Precision.
If that is really what's going on, this is a colossal waste of time.
There seems to be some attitude here that the AP is in a whole other league from the Sound Technology equipment that JC uses. Nothing could be further from the truth.
The Sound Technology gear was outstanding in its day, as is the Audio Precision. But here is the deal -- the AP is basically the same thing as the ST, except implemented with a digital *interface* so that it can be controlled via a computer rather than front panel pushbuttons.
(I'm simplifying slightly here, as the AP does offer a digital-domain measurement system that is like having another piece of test equipment inside the same box, but that is not relevant to this discussion.)
What I'm saying is that there has been *no* massive breakthrough in distortion measurement by AP since the ST units were designed. The fundamental performance between the two is virtually identical.
Now, when John Curl uses the ST by itself, there is no way in the world he can see what he sees. He has to also uses an external FFT on the residual output from the ST to look at harmonics that would otherwise be buried in the noise. The same is absolutely true of the AP. You won't be able to see what John is seeing without using an external FFT.
If the European guy with the AP is doing so, then please ignore this post.
Charles Hansen |
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| Steve Eddy |
| quote: | Originally posted by Charles Hansen
Now, when John Curl uses the ST by itself, there is no way in the world he can see what he sees. He has to also uses an external FFT on the residual output from the ST to look at harmonics that would otherwise be buried in the noise. The same is absolutely true of the AP. You won't be able to see what John is seeing without using an external FFT.
If the European guy with the AP is doing so, then please ignore this post. |
Post ignored.
The European guy with the AP is measuring the residual output of the AP's generator after the fundamental has been notched out.
With statistical averaging, he's measuring a good 20dB below where John is measuring yet so far, even when measuring the most bog standard A/V cable, none of the high order harmonics that John has been routinely measuring are evident.
So it's beginning to look as if the distortion John has been measuring is being produced by his 1700B rather than the cables as John has claimed.
However to make absolutely sure, because John and the European guy with the AP didn't measure exactly the same cables, I made up two sets of the same cables and sent one set to John (which he has already measured and reported on) and the other set to the European guy with the AP.
I'll report the results as soon as I receive them.
The European guy with the AP by the way is Bruno Putzeys, a chief engineer at Philips' Digital Systems Labs in Belgium.
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| SY |
| quote: | | So it's beginning to look as if the distortion John has been measuring is being produced by his 1700B rather than the cables as John has claimed. |
I wouldn't jump so fast to that conclusion. There hasn't been nearly enough examination of other possible variables to assert such a thing. It MIGHT be true, but it might not. |
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| Charles Hansen |
Steve -
You don't have an AP. I've owned and used one for over 10 years. I know quite a bit more about its capabilities than do you.
My Dual-Domain System One cannot duplicate the method used by Curl. I seriously doubt that Putzeys' AP can either.
Please show that Putzeys' method (in at least a general way) duplicates Curl's method of sending a sine wave through the DUT, notching out the fundamental with an analog filter, making 100 FFTs of the resultant signal, and then averaging them together to reduce the noise contribution.
Charles Hansen |
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| SY |
| Charles, might it not be a better procedure to take 100 windowed time domain measurements, average, then FFT? |
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| Charles Hansen |
Hello SY,
Yes, you are correct.
The point that I was making was that my Dual-Domain System One won't allow for averaged digital measurements. Furthermore, it cannot do a digital measurement at the same time it does an analog measurement. Therefore it is fundamentally incapable of reproducing Curl's method without the use of an external FFT that can average many measurements.
Is Putzeys' AP different than mine in this regard? It's possible, but I doubt it. However, since Eddy is trying to use Putzeys' measurement to refute Curl's results, it is incumbent upon Eddy to show that the two results can be compared.
Charles Hansen |
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| Steve Eddy |
| quote: | Originally posted by SY
I wouldn't jump so fast to that conclusion. There hasn't been nearly enough examination of other possible variables to assert such a thing. It MIGHT be true, but it might not. |
What conclusion? How do you get a conclusion out of "it's beginning to look like"?
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| SY |
| Because neither you nor I have enough information to know WHAT the heck it "looks like." Why call out one hypothesis when its no more or less likely than (probably) a dozen more? |
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| Steve Eddy |
| quote: | Originally posted by Charles Hansen
You don't have an AP. I've owned and used one for over 10 years. I know quite a bit more about its capabilities than do you.
My Dual-Domain System One cannot duplicate the method used by Curl. I seriously doubt that Putzeys' AP can either. |
Bruno's not using a System One Dual Domain. He's using a System Two Cascade.
| quote: | | Please show that Putzeys' method (in at least a general way) duplicates Curl's method of sending a sine wave through the DUT, notching out the fundamental with an analog filter, making 100 FFTs of the resultant signal, and then averaging them together to reduce the noise contribution. |
Sure.
This is of the cheap A/V cable. Generator set at 1kHz, 30mV, just as John used when he made his Mac The Scope plots. The dB scale is relative to the 30mV fundamental. The FFT analyzer is set to synchronous averaging which allows measurement significantly below simple power averaging, which gives this result:
Even this is measuring below where John says he's measuring. If you take where John says he's measuring and overlay it on the first plot, it would look like this:
se |
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| Steve Eddy |
| quote: | Originally posted by Charles Hansen
The point that I was making was that my Dual-Domain System One won't allow for averaged digital measurements. Furthermore, it cannot do a digital measurement at the same time it does an analog measurement. Therefore it is fundamentally incapable of reproducing Curl's method without the use of an external FFT that can average many measurements.
Is Putzeys' AP different than mine in this regard? It's possible, but I doubt it. |
Yes, it's different from yours in that regard, it being a newer System Two Cascade and not an older System One Dual Domain.
| quote: | | However, since Eddy is trying to use Putzeys' measurement to refute Curl's results, it is incumbent upon Eddy to show that the two results can be compared. |
Been there, done that.
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| Steve Eddy |
| quote: | Originally posted by SY
Because neither you nor I have enough information to know WHAT the heck it "looks like." Why call out one hypothesis when its no more or less likely than (probably) a dozen more? |
Ok. So let's hear another hypothesis or two. I've always kept open the possibility that Bruno is being dishonest.
se |
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| Steve Eddy |
| quote: | Originally posted by SY
Charles, might it not be a better procedure to take 100 windowed time domain measurements, average, then FFT? |
That's what the System Two Cascade's FFT analyzer does in synchronous averaging mode.
se |
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| mefinnis |
| quote: | | Originally posted by Steve Eddy Ok. So let's hear another hypothesis or two. I've always kept open the possibility that Bruno is being dishonest. |
Gee ...... I hope Bruno isn't listening!
Have we invited Bruno to actually join the discussion directly, or are we simply going to have a relayed report .... ???
I cannot profess to even remotely understand the finer technical points in this thread, or it's predecessor, but it is nice to see the thread come back to a straight technical discussion.
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| Steve Eddy |
| quote: | Originally posted by mefinnis
Have we invited Bruno to actually join the discussion directly, or are we simply going to have a relayed report .... ??? |
I've invited him, but he seems to prefer to stick to rec.audio.high-end.
| quote: | | I cannot profess to even remotely understand the finer technical points in this thread, or it's predecessor, but it is nice to see the thread come back to a straight technical discussion. |
Yes. Just hope it stays that way.
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| Charles Hansen |
| quote: | Originally posted by Steve Eddy
Even this is measuring below where John says he's measuring. If you take where John says he's measuring and overlay it on the first plot, it would look like this:
se |
Steve,
You have conveniently included the phrase "where John says he's measuring". Now I haven't been following this thread, so I don't know what Curl claims in this regard. But if you stop for a moment and look at the situation you will realize that the graph you posted is incorrect.
First of all, please consider the residual distortion of the ST versus the AP. If you go to the AP website you can see that the distortion spec for the System Two Cascade is:
Residual THD+N
20 Hz-20 kHz </=(0.0004% + 1 mV), 22 kHz BW [-108 dB]
</=(0.0006% + 2 mV), 80 kHz BW [-104 dB]
</=(0.0015% + 6 mV), 500 kHz BW [-96.5 dB]
10 Hz-100 kHz </=(0.0040% + 6 mV), 500 kHz BW [-88 dB]
Now go to the ST website, where it is claimed that the 1700 series measures distortion down to 0.0009%. Unfortunately, there is no additional information regarding the measurement conditions. Therefore we cannot directly compare the exact performance of the two machines.
However, can see that they are in the same ballpark. Depending on the test conditions of the AP, in some circumstances it is slightly *better* than the ST's spec, and in some circumstances it is slightly *worse* than the ST's spec.
Like I said before, the AP is a wonderful instrument. So is the ST. Audio Precision has *not* made some tremendous breakthrough in analog distortion measurements since the ST was designed. (In fact, the last breakthrough I can remember in analog distortion measurements was when HP developed the 200 series oscillators. That was a *long* time ago.)
And just to complicate things further, Curl has modified his ST to reduce the residual distortion. So it is quite likely that Curl's setup has a *lower* residual than your highly vaunted AP. However, we cannot ascertain this at the current time. Suffice it to say that the distortion residual of the generators is roughly comparable.
Next we turn to the analyzer side. While it is true that the System Two has some additional capabilities over the System One, I still don't believe that it can (by itself) duplicate the measurements that Curl has made. I have downloaded the user manual and failed to find any evidence that it can. In fact, everything I have read points to the opposite, that it *cannot* duplicate Curl's measurements. Now I may be wrong about that, as I haven't read the full 720 (!) pages in great detail, nor have I any experience with that particular machine.
But the graphs you have posted from Putzeys' work leads me to the conclusion that he is absolutely *not* resolving as low as Curl is in his measurements.
Simply put, it is clear (based on the above discussion) that your red overlay of Curl's measurements should be moved down at least 20 dB relative to Putzeys' measurements. When that is done, you will see that Putzeys' measurements are *not* adequate to resolve the effects that Curl is seeing.
Charles Hansen |
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| SY |
| quote: | Originally posted by Steve Eddy
Ok. So let's hear another hypothesis or two. I've always kept open the possibility that Bruno is being dishonest.
se |
"Speculation in the absence of data is a capital mistake." When you're talking about signal levels 6 orders of magnitude down from 30mV, there's no shortage of possible sources for error or unaccounted for variables. Including the source that John claims, the wire itself.
John is making some extraordinary claims, especially the one about being able to distinguish wires which have carried signal from those which haven't. I haven't seen any extraordinary proof, just some informal measurements. In the scientific world where I grew up, the first thing one does when getting results like this is to consult with peers, bring other experts into the picture to try to eliminate error sources or unaccounted for variables, publish full and complete procedures for people to replicate, and in general, tighten up the protocols. It's certainly the least that I would do, but I'm not an engineer, so what the heck would I know. |
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| mrfeedback |
Originally posted by SY
"Speculation in the absence of data is a capital mistake." When you're talking about signal levels 6 orders of magnitude down from 30mV, there's no shortage of possible sources for error or unaccounted for variables. Including the source that John claims, the wire itself.
Sure, we are talking about micro levels and extreme care is needed when making these kinds of measurements as I am sure John (and Bruno) have.
John is making some extraordinary claims, especially the one about being able to distinguish wires which have carried signal from those which haven't.
Yes that one caught my eye too - if Johns measurements are proven correct then this is interesting indeed.
I haven't seen any extraordinary proof, just some informal measurements.
Sure, but we are working on establishing a proof (or experimental errors).
In the scientific world where I grew up, the first thing one does when getting results like this is to consult with peers, bring other experts into the picture to try to eliminate error sources or unaccounted for variables, publish full and complete procedures for people to replicate, and in general, tighten up the protocols.
We are getting there.
It's certainly the least that I would do, but I'm not an engineer, so what the heck would I know.
You mean you know every thing about ****** all, and ****** all about everything ? ......... ;)
I have some comments/questions .............
In the graph of JC's measurements there is no 4kHz residual ???.
The graphs contain both even and odd order harmonic content.
This suggests both symmetrical distortion (peaks compression)and non symmetrical distortion - ie directionality - http://www.dwelle.de/rtc/infotheque...qualpar_04.html
Connectors have reputation for sounding different, and according to what I have read it seems that variable connectors (Rca ?) are being included in the measurements.
For this reason (elimination of one of the variables), when I get the direction test cables from Stuart, I will be listening to bare ended cables/wires connected to a fixed connection setup - ie solder on test or some kind of quick connect so that the only variables are the wire and absolute time.
In the name of correctness, I reckon that this kind of approach needs to be used/stated in further testing of extreme low levels of distortions in cables due to wires and/or dielectrics.
I understand that John has gone to these extreme measures in order to more clearly quantify the sonic differences in cables that he is hearing/heard.
If these kinds of measurements can be proven, then all of this discussion is indeed interesting.
That these measurements have not been proven conclusively previously only indicates that properly sensitive measurements have not been performed and collaborated yet by independant parties.
I look forward to further scientific collaboration and resoloution.
Eric. |
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| millwood |
| quote: | Originally posted by mrfeedback
Originally posted by SY
[B]That these measurements have not been proven conclusively previously only indicates that properly sensitive measurements have not been performed and collaborated yet by independant parties.
Eric. |
That these measurements have not been proven conclusively previously only indicates that some of us can still make baseless and anecdote-driven claims, :)
Seriously, I thought one only makes a claim when backed with data, facts and measurement.
Ever scince Al Gore invented the Internet 10 years ago, anyone can make claims unless they are proven false. |
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| Steve Eddy |
| quote: | Originally posted by Charles Hansen
You have conveniently included the phrase "where John says he's measuring". Now I haven't been following this thread, so I don't know what Curl claims in this regard. But if you stop for a moment and look at the situation you will realize that the graph you posted is incorrect. |
It's not incorrect regarding where John claims he's measuring. Here's what John himself said:
Steve, the notch filter in the 1700B notches out to somewhere between -94 and -100dB This can be shown by the RESIDUAL of the THD at all levels is a little less than .002% or -94dB. Of course at very low levels, NOISE makes the residual appear to increase on the meter. This residual includes the unnotched fundamental ( the highest peak on the left side at 1KHz), the averaged distortion residual, and NOISE. At low levels, noise is all important, and this is why I must use signal averaging or very narrow bandwidth filtering to remove enough noise to look at the distortion residual. If you start with my graphs with the IKHz (notch) then you can see that the noise boundary is about -125dB. The distortion occurs in this case about -115 to -120dB, or even as much as -110dB if the notch is not complete.
John says that his noise boundary is about -125dB relative to the 30mV fundamental. And that the high order distortion products are between -115 to -120 dB relative to the 30mV fundamental.
Since the dB scale in Bruno's plots are also relative to the 30mV fundamental, what I've overlaid corresponds to what John claims to be measuring.
The overlay by the way was made based on this Mac The Scope plot of his of a Radio Shack Gold interconnect.
| quote: | First of all, please consider the residual distortion of the ST versus the AP. If you go to the AP website you can see that the distortion spec for the System Two Cascade is:
Residual THD+N
20 Hz-20 kHz </=(0.0004% + 1 mV), 22 kHz BW [-108 dB]
</=(0.0006% + 2 mV), 80 kHz BW [-104 dB]
</=(0.0015% + 6 mV), 500 kHz BW [-96.5 dB]
10 Hz-100 kHz </=(0.0040% + 6 mV), 500 kHz BW [-88 dB]
Now go to the ST website, where it is claimed that the 1700 series measures distortion down to 0.0009%. Unfortunately, there is no additional information regarding the measurement conditions. Therefore we cannot directly compare the exact performance of the two machines. |
Um, that bit on the ST website is for their current model 1700 series. John's using a 25 year old 1700B which he says he's upgraded a few of the opamps in.
Are you saying that ST's current model 1700 series has in no way changed or otherwise improved over what they were building 25 years ago?
And they have three different models. The 1700 "Distortion Measurement System," the 1701 "Precision Distortion Measurement System," and the 1710 "Professional Distortion Measurement System."
They say of these:
Fully automatic nulling circuits measure distortion as low as 0.0009% in five seconds.
How do you know which of these three models that that 0.0009% refers to? Does it refer to the budget 1700, which "provides excellent performance at an attractive price" or does it refer to the 1701 which "features extremely low distortion and noise at high frequencies"?
So how on earth can you conclude that that ambiguous "0.0009%" figure has ANYTHING to do with a 25 year old 1700B?
| quote: | | However, can see that they are in the same ballpark. |
Great. Except that John's not using any of the current production models from ST.
| quote: | | Depending on the test conditions of the AP, in some circumstances it is slightly *better* than the ST's spec, and in some circumstances it is slightly *worse* than the ST's spec. |
How can you say that when ST gives no conditions whatsoever for that 0.0009%" spec?
| quote: | | Like I said before, the AP is a wonderful instrument. So is the ST. Audio Precision has *not* made some tremendous breakthrough in analog distortion measurements since the ST was designed. (In fact, the last breakthrough I can remember in analog distortion measurements was when HP developed the 200 series oscillators. That was a *long* time ago.) |
But what we do have are measurements made using a 25 year old ST 1700B and we have measurements made using a more recent AP System Two Cascade. And going by what John himself claims as to where he's measuring, the System Two Cascade is resolving significantly lower.
And even if one assumes that the System Two Cascade is only measuring as far down as where John's measuring, there's still no evidence of the high order distortion products which are plainly visible in John's plots.
| quote: | | And just to complicate things further, Curl has modified his ST to reduce the residual distortion. |
He says he's replaced a few of the opamps. That's it.
| quote: | | So it is quite likely that Curl's setup has a *lower* residual than your highly vaunted AP. |
But if John's claims are correct, it's not even close.
AP specs individual residual harmonics to be no greater than -130dB. Which is where it's at in Bruno's plots. John says in his system, noise is bottoming out at about -125dB. Which puts his third harmonic at about -115dB.
| quote: | | However, we cannot ascertain this at the current time. Suffice it to say that the distortion residual of the generators is roughly comparable. |
We have the FFT measurements from the System Two Cascade. We have John's claims as to what the levels are relative to the fundamental in his plots. So unless John has absolutely no clue just where he's measuring, it's rather clear that the System Two Cascade is resolving levels well below John's measurements.
| quote: | | Next we turn to the analyzer side. While it is true that the System Two has some additional capabilities over the System One, I still don't believe that it can (by itself) duplicate the measurements that Curl has made. I have downloaded the user manual and failed to find any evidence that it can. In fact, everything I have read points to the opposite, that it *cannot* duplicate Curl's measurements. Now I may be wrong about that, as I haven't read the full 720 (!) pages in great detail, nor have I any experience with that particular machine. |
It's really quite simple. The output of the oscillator feeds the DUT, the output of the DUT goes into the filter module where the fundamental is notched out, and the output of the filter module gets fed into the FFT analyzer.
It's clearly able to do it or it couldn't produce the plots that have been provided.
| quote: | | But the graphs you have posted from Putzeys' work leads me to the conclusion that he is absolutely *not* resolving as low as Curl is in his measurements. |
If that's the case, then John has absolutely no clue what he's doing or where he's measuring.
| quote: | | Simply put, it is clear (based on the above discussion) that your red overlay of Curl's measurements should be moved down at least 20 dB relative to Putzeys' measurements. When that is done, you will see that Putzeys' measurements are *not* adequate to resolve the effects that Curl is seeing. |
Why is it clear that the overlay should be moved 20dB down below the System Two Cascade's measurements? Based on where John claims he's measuring using a piece of equipment that he's been using for over 20 years, the overlay is right where it should be. If the overlay is wrong, then you need to tell John to learn a bit more about his 1700B because he obviously has no idea what its level of performance actually is.
se |
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| kamskoma |
Ok John I will open another bottle of Barolo and go back to the Xmas duties.
I have a AP portable one it may be Ok I will blow the dust off this bastard and try it together with my Card Deluxe soundcard later this week, maybe this can measure interconnect wires wich I am now very interested in maybe this can make me a fortune my new business interconnect cable maker with technical specifications on every handmade cable. |
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| Charles Hansen |
Steve,
Your combination of ignorance and willingness to argue over *anything* is too much for me.
1) Actually all of the ST 1700 series instruments were discontinued many years ago. The don't have a "current model" 1700 series.
2) There have been no fundamental breakthroughs in the performance of low distortion audio oscillators since the HP 200 series over 50 years ago.
3) At the risk of being repetitive, Curl's ST oscillator has roughly (say within 5 dB or so) the same residual distortion as the AP.
4) Nowhere that I can find in the AP manual does it say that unit is capable of the test you claim is being made.
5) I'd be willing to bet that Putzeys test setup is not what you claim it is. My strong suspicion is that he is instead using the digital analyzer section of his AP to perform both the notch filter and the FFT. This approach will not work for the very simple reason that the ADCs used in that device are incapable of performing at the required level of resolution.
Please confirm that Putzeys' measurement is being made in the manner you specified. You could do this in a few different ways.
a) Find the specific passages in the AP manual that even show that this is possible. (This of course wouldn't be conclusive, but it would be a start.)
b) Post a detailed description of Putzeys' setup *in his own words*.
c) The test setups for the AP can be stored as test protocols. Post Putzeys' test protocol here and I will take it to a colleague's that has a System Two and will confirm if he has in fact replicated Curl's method in at least a general way.
Until such time, I reject your claim that Putzeys' test in any refutes Curl's findings. While it is certainly possible, at this point I do not believe that the method Putzeys used has the resolving power of Curl's test.
Charles Hansen |
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| SY |
Without proper controls, capability study, repeatability and reproduceability measurements, and the systematic elimination of all possible variables, it's unclear what the "resolving power" or Curl's test actually is.
These are extraordinary claims and ought to be made with great care. |
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| Charles Hansen |
Hello SY,
Actually I think Curl's method is rather simple and easily reproduced.
1) Use a high-quality, low-distortion analog oscillator.
2) Run the signal through the DUT.
3) Notch out the fundmental tone with an analog notch filter.
4) Make multiple time-windowed digital readings of the resultant residual output.
5) Perform an FFT on the averaged signal to generate a spectrum of the residual distortion.
However as near as I can tell, Putzeys has not done this. Based on what I've read on this forum and in the AP manual, I think what Putzeys has done is to:
1) Use a high-quality, low-distortion analog oscillator.
2) Run the signal through the DUT.
3) Convert the analog signal to digital.
4) Notch out the fundmental tone with a digital notch filter.
4) Make multiple time-windowed digital readings of the resultant residual output.
5) Perform an FFT on the averaged signal to generate a spectrum of the residual distortion.
If this is true, the problem is in step #3 where the analog signal is converted to digital. The ADCs used in the AP have insufficient resolving power to replicate Curl's findings.
Of course, I could be wrong. I am waiting for Eddy to confirm in an unambiguous way Putzeys' setup.
Charles Hansen |
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| SY |
I can't comment about what Putzeys has done- I'll be interested in what he has to say. But when doing measurements of this low level, even a good procedure can still end up giving one unexpected errors. There are a lot of subtleties which don't matter when you're doing the sort of normal, gross measurement typical of audio, but can bite you in the butt when trying to push the capabilities of your equipment. That's why I keep harping on John to open up his lab to me (or someone else of similar qualification) to double check everything and try to eliminate any other error sources that he may have missed.
If we were talking about anything less than extraordinary claims that fly in the face of known physics, I wouldn't bother- I've got a life and a business to run. But either there's something funny in the test setup or there's something interesting here, and I can't tell which is which from a simple laundry list and the rather incomplete analysis so far presented. So, the half-hour drive and an afternoon playing with wires is worth it to me to try to resolve this question. |
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| Charles Hansen |
Hello SY,
Have you asked John to visit his lab? I think that such an undertaking would resolve a lot of questions. Thank you for making such a generous offer of your time. If John has declined your offer, please let me know and I'll see if I can persuade him to change his mind.
Charles Hansen
PS -- John already did this with another engineer (I think his name was Peter) to try an resolve some questions on the Audio Asylum forum. Unfortunately, it didn't diminish in any way Eddy's penchant for arguing. |
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| SY |
| Yes, I made the offer earlier in this thread. John hasn't responded one way or the other. Making Steve happy is not my goal here, I'm just trying to get at what's going on. |
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| kamskoma |
Regarding ST do they sell the ST 1700 series analyzers? I have visit their site wich is a little bit obscure, why do they have this dark look? BTW I own a ST1000 wich is a nice instrument.
For a couple of years ago I talked to a guy who constructed the AMBER analyzers wich I think was even better then ST 1700 series. |
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| Fred Dieckmann |
"Making Steve happy is not my goal here"
No, it is more like helping Steve make every else unhappy. I don't understand why anyone tolerates Mr. Eddy's unending fixation with persecuting Mr. Curl. Mr. Eddy has fallen flat on his face in nearly every technical argument of his that I have tried to follow. When people like him run off everyone worth reading on the forum I will remind you of your statement........
I wouldn't have anybody in my lab or house that has any links to someone that is practically a stalker. The same people that scream for the physics and measurements to unravel the gap between what we hear and what we can explain and measure, are the first ones to try to dismiss any measurements or theories made in pursuit of this goal. Like you said people have jobs and a life. Mr. Curl's is to continue be one of the most respected audio designers in the world and Mr. Eddy's seem to be spending all his waking hours on the Internet rguing about things he doesn't have a clue about......... Given a choice between one or the other of these gentleman's presence here, I think it is a no brainer who almost everyone would prefer to be here.
Fred Dieckmann |
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| SY |
| Fred, I think I'm pretty clear about my goal. I've never met Curl, or Eddy, or you. Why the conspiracy theory? |
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| grataku |
SY,
I am not talking about this thread specifically but I always seen some type of affinity, or like-mindedness, between you and SE. Maybe it's just geography. ;)
As far as opening-up laboratories I think it's a bit pretentious on anyone's part, and it's almost never done, at least in science there is an unspoken sense of how far you can go even with a conversation. Going in to check a colleague's work is certainly beyond the boundaries. In industry investment bankers are probably the only ones to be allowed in. |
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| SY |
| Completely the contrary. When I was doing science, this was the kind of thing we did all the time to resolve conflicting data or to sort out puzzling stuff. I can give some specific examples, if you like. |
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| grataku |
| I don't know what kind of science you have been involved. Where I am we keep our experiments hidden even from the colleagues in our own group. Especially! |
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| SY |
My professional specialty, the physics of conductive materials.
Geographically, BTW, I'm much closer to John Curl. In fact, I'm down in Berkeley two or three times a week. |
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| kamskoma |
| Wich type of conducting material will give best results regarding audible distortion types?? |
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| SY |
| quote: | Originally posted by kamskoma
Wich type of conducting material will give best results regarding audible distortion types?? |
Shown to be audible? Probably not much difference between one metal and another. Claimed audible? Pick one at random, you'll find its advocates and detractors. |
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| mefinnis |
| quote: | Originally posted by SY
"Speculation in the absence of data is a capital mistake." ......... In the scientific world where I grew up, the first thing one does when getting results like this is to consult with peers, bring other experts into the picture to try to eliminate error sources or unaccounted for variables, publish full and complete procedures for people to replicate, and in general, tighten up the protocols. It's certainly the least that I would do, but I'm not an engineer, so what the heck would I know. |
Quite a bit from reading this :)
I am no engineer either .... but my field (medicine) is rife with marginal claims and we are talking orders of magnitude difference in $$$ vested interest.
I would echo SY's statement and close with one of my favourite quotes:| quote: | In God We Trust .....
Everyone else should bring data! |
;) |
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| kamskoma |
| Ok! I go for car ignition cables from now ;-) |
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| Steve Eddy |
| quote: | Originally posted by Charles Hansen
Your combination of ignorance and willingness to argue over *anything* is too much for me.
1) Actually all of the ST 1700 series instruments were discontinued many years ago. The don't have a "current model" 1700 series. |
That might come as a surprise to the folks at Sound Technology.
http://www.soundtechnology.com/ST1700S_PIC.htm
Sound Technology manufactures three Distortion Measurement Systems designed to provide precision audio measurements quickly and easily.
If the 1700 series has long since been discontinued, why are they saying on their web site that they manufacturing a 1700 series? And why do they have price list request links for stuff that they've long since discontinued?
Far as I can tell, everything in their Test Gear line, which includes the ST1500 series, the ST4000 series, the ST3000 series and the ST1700 series is in current production.
| quote: | | 2) There have been no fundamental breakthroughs in the performance of low distortion audio oscillators since the HP 200 series over 50 years ago. |
So? What's that to do with the oscillator in John's 1700B?
| quote: | | 3) At the risk of being repetitive, Curl's ST oscillator has roughly (say within 5 dB or so) the same residual distortion as the AP. |
I've seen no evidence of that whatsoever. And going by John's own claims, that's clearly not the case.
| quote: | | 4) Nowhere that I can find in the AP manual does it say that unit is capable of the test you claim is being made. |
Geez, Charles, even the System One was capable of that!
Prove your finest designs with System One’s ultra-high performance; typical 0.0007% distortion, 0.03 dB flatness, 1.2 microvolt noise levels in the audio bandwidth. Use FFT analysis following the analog notch filter to resolve distortion components 145 to 150 dB below the fundamental.
| quote: | | 5) I'd be willing to bet that Putzeys test setup is not what you claim it is. My strong suspicion is that he is instead using the digital analyzer section of his AP to perform both the notch filter and the FFT. This approach will not work for the very simple reason that the ADCs used in that device are incapable of performing at the required level of resolution. |
No, it's using the analog notch filter, just as the System One did.
| quote: | | Please confirm that Putzeys' measurement is being made in the manner you specified. You could do this in a few different ways. |
Who cares HOW they were made? The measurements speak for themselves. Show me evidence that John's measuring below that. His Mac The Scope plots don't show it. Nor do John's own claims as to the levels he's measuring.
se |
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| kamskoma |
Please tell me how to connect my test instruments for the cable test a schematic diagram would be nice with all component parts.
The instruments is AP Portable One and a PC with Card DeLuxe soundcard from Digital Audio.
1.Connection diagram
2.Signal level
3.Thank You |
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| millwood |
| quote: | Originally posted by Fred Dieckmann
I don't understand why anyone tolerates Mr. Eddy's unending fixation with persecuting Mr. Curl. |
I am not sure where you read this "persecuting" thing. John made a claim and Steve challenged him on that on technical ground. As far as I am concerned, one can raise questions on claims made by anyone, Mr. Curl included.
| quote: | Originally posted by Fred Dieckmann
Mr. Eddy has fallen flat on his face in nearly every technical argument of his that I have tried to follow. |
so what? someone who has always been wrong will remain wrong forever? or vice versa? there is no logic in this. |
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| mefinnis |
Please remember there are neophytes like me following this thread and some of the questions raised by Charles seem worthy of verification.
IF you are correct in your description of Bruno's set-up, then Charles' request for verification would seem easily achieved and in doing this we (the collective watching) have eliminated another possible source of discrepancy.
As stated, I am no engineer, so when someone who has clearly been using "similar" equipment (believing Charles' claim on word) raises a concern I would feel a lot more comfortable if we could put his mind at rest that "all is well and proper".
One of the major irritations to yourself (and many of the rest of us) in the previous thread was certain people taking the position "I know, therefore it is true" ...... I agree, these people have achieved nothing but to diminish their own standing in our general community. And their attemps to reduce this thread to a similar level are sad.
You may well be absolutely correct in what you say to Charles ...... for the sake of the rest of us, could you verify Bruno's set-up for Charles.
You asked for a technical/scientific thread and there a good number of us out there who are watching with interest.
mark |
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| john curl |
| Sy, if you wish, we could meet together and I could run a few tests for you. I am on MLK in north Berkeley. E-mail me and I will give you my complete address. We could even measure a coat hanger together. I have one around here somewhere. Sorry, I missed your original suggestion about this, I will back up and look for it. For some reason, I thought you were in a far away location. If you can find something that I can further address, I would be grateful. |
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| SY |
| Thanks, John, that's really appreciated. I'll email you from home tonight and we'll make arrangements. |
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| mefinnis |
Good on you John.
SY has ever been an objective and rational voice around here and allowing him to verify or otherwise what you have found valuable.
mark |
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| Steve Eddy |
| quote: | Originally posted by kamskoma
Please tell me how to connect my test instruments for the cable test a schematic diagram would be nice with all component parts.
The instruments is AP Portable One and a PC with Card DeLuxe soundcard from Digital Audio.
1.Connection diagram
2.Signal level
3.Thank You |
Does the Portable One have an output for THD residual? If so, then you can run that into your FFT.
But basically, the test goes like this:
Signal Generator --> DUT --> Notch filter --> FFT
The signal levels used for Bruno's tests, which were the same as those used for John's tests which he produced the Mac The Scope plots with, were 30mV at 1kHz.
se |
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| Steve Eddy |
| quote: | Originally posted by mefinnis
Please remember there are neophytes like me following this thread and some of the questions raised by Charles seem worthy of verification.
IF you are correct in your description of Bruno's set-up, then Charles' request for verification would seem easily achieved and in doing this we (the collective watching) have eliminated another possible source of discrepancy.
As stated, I am no engineer, so when someone who has clearly been using "similar" equipment (believing Charles' claim on word) raises a concern I would feel a lot more comfortable if we could put his mind at rest that "all is well and proper".
One of the major irritations to yourself (and many of the rest of us) in the previous thread was certain people taking the position "I know, therefore it is true" ...... I agree, these people have achieved nothing but to diminish their own standing in our general community. And their attemps to reduce this thread to a similar level are sad.
You may well be absolutely correct in what you say to Charles ...... for the sake of the rest of us, could you verify Bruno's set-up for Charles.
You asked for a technical/scientific thread and there a good number of us out there who are watching with interest. |
Fair 'nuff.
Below is the block diagram for the fully-loaded System Two Cascade. As you can see, the analog analyzer's post notch residual output can feed into the A/D and subsequently to the digital analyzer for FFT analysis. Since the System Two Cascade's analog notch filter is part of the analog analyzer, it's possible to do the measurements just as John is doing his, feeding the residual output of his 1700B into his FFT analyzer.
Even the System One had this capability (depending on which model and options) so I'm at a loss as to why Charles keeps claiming that not even the System Two can do it and demanding proof of it.
In any case, I'll confirm Bruno's setup and post his response here when I get it. He might be off for the holidays so it might not be until after New Years. |
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| fdegrove |
Hi,
| quote: | | there is no logic in this. |
Maybe not logic per se but the likelyhood for erroneous conclusions is growing as days go by.
Anyway, for all of those who followed the previous thread where I said that Dr. De Ceuninck had measured distortion in wires:
There was a good reeason why I didn't want to disclose this professor's full name besides the commercial ones. (Not commercial on my part in anyway today.)
At the time of writing, due to my residing in Germany a few years back, I had lost touch with this professor and moreover, due to inadvertance on my part, had lost his private telephonenumber as well.
This afternoon I got a call from a friend, manager of Phelps-Dodge Europe, and as we'd visited the professor at home a few times, I asked if he had the professors' telephone numbers.
He did and passed them on to me.
So, here's the deal: I'll get in touch with the professor asap and ask him how much he can divulge on his research regarding his measurements and if we get lucky we'll come up with solid proof.
I don't doubt for a minute that if we can get his go ahead it will be fulproof.
Further during the telcon I mentioned the addition of manganese to Cu to promote crystal formation as SE suggested before: guess what?
The reason this is done is to augment the tensile strenght of the Cu wire according to him, NOT more crystals.
Which, BTW, is not what you want in audiowire, the less crystal boundaries the better.
Ag, by its very nature, will tend to form less crystals for a given length of wire than Cu.
Ergo, hint #4 : Electromigration.
Going back to the university where our friend the professor works, to do this kind of research they don't use ordinary ( excuse me) test equipment but an electron microscope amongst other countless equipment.
Hope this helps,;) |
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| Steve Eddy |
| quote: | Originally posted by fdegrove
Further during the telcon I mentioned the addition of manganese to Cu to promote crystal formation as SE suggested before: guess what?
The reason this is done is to augment the tensile strenght of the Cu wire according to him, NOT more crystals.
Which, BTW, is not what you want in audiowire, the less crystal boundaries the better.
Ag, by its very nature, will tend to form less crystals for a given length of wire than Cu. |
Where do you get "Ag" from manganese?
But let's refresh. When I asked if the process you were referring to was their process of adding manganese, you said:
No....You won't even have to add manganese to copper anyway, it contains some in its natural raw state already.
I replied:
But they add more in order to improve crystal formation.
I didn't say anything about growing more crystals.
And what I said was based on the claims made by the inventors of the process in the patent (4,059,437):
It has been found under the present invention that by adding to oxygen-free copper small amounts of manganese in addition to the manganese impurity level present, that the abnormal grain structure can be lessened or eliminated, and that consequently the roughened or "orange peel" surfaces and various forms of cracking and uneven flow during cold forming can be alleviated or eliminated.
Amounts of manganese added at any convenient stage during the production of the oxygen-free copper in the range of approximately 1 to approximately 100 parts per million by weight provide enhanced grain size control during annealing of the copper, a minimum electrical conductivity of 100% I.A.C.S., and increased ductility of the copper as cast or fabricated. Amounts of manganese added in the range of approximately 1 to approximately 50 parts per million by weight provide enhanced grain size control during annealing of the copper, a minimum electrical conductivity of 101% I.A.C.S., and increased ductility of the copper as cast or fabricated. When at least approximately 30 parts per million by weight of manganese are added, ductility is maximized. In each instance, the "orange peel" surfaces and various forms of cracking and uneven flow during cold forming are aleviated or eliminated.
And by the way, this discussion is not about these issues. It's about whether the distortion that John has been measuring is being produced by the wires themselves and has nothing to do with metallurgy and the like. If you want to discuss those issues, let's start a new thread.
se |
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| millwood |
| quote: | Originally posted by fdegrove
Hi,
Maybe not logic per se but the likelyhood for erroneous conclusions is growing as days go by.
Hope this helps,;) |
Frank, I love to chat with you on this logic thing but this is, as its orginator had hoped, a technical discussion and please do you best NOT to disturb and distract this otherwise very interesting discussion.
If you wish to discuss logic somewhere in this forum, please drop me a line and I am happy to go down with you on your own thread. But in the meantime, please respect Steve's wishes and lease this thread intact and alone. Thank you.
I hope I have made myself clear enough. |
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| SY |
| quote: | Originally posted by fdegrove
Hi,
Going back to the university where our friend the professor works, to do this kind of research they don't use ordinary ( excuse me) test equipment but an electron microscope amongst other countless equipment.
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What, you mean everyone doesn't have an electron microscope? |
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| fdegrove |
Hi,
| quote: | | And by the way, this discussion is not about these issues. |
O.K. let's forget about the manganese for now.
| quote: | | It's about whether the distortion that John has been measuring is being produced by the wires themselves and has nothing to do with metallurgy and the like. |
OTOH it helps to know where possible distortion artefacts could come from, it gives you insight into John's motivation for trying to measure them in the first place.
If the sole purpose of this thread is to find out whether John is measuring what he thinks he's measuring then I feel that it serves very little other than endless argument and it will require John Curls participation in the first place.
Not my idea of the purpose of diyAudio but who am I anyway.
| quote: | | If you want to discuss those issues, let's start a new thread. |
If you think there's sufficient interest I may do that somewhere in January.
BTW, the wire you sent arrived today in perfect condition.
Cheers,;) |
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| fdegrove |
Hi,
| quote: | | What, you mean everyone doesn't have an electron microscope? |
I had one on my wish list for Santa but it didn't pass through the chimney.:D
What was used, if I'm not mistaken, was a scanning electron microscope.
Still, I'm impressed with the machine, SY.
Cheers,;) |
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| SY |
| One of the positive fallouts from the Silicon Valle | | | |
