Power cord and IC affecting sound..

[mtrycraft]

Given the possibility that large acoustic signals can jitter the sound enough to allow 1.5 uSec discrimination, we now are faced with the possibility that 1.5 uSec waveform sloppyness as a result of amp/wire/speaker combinations is audible..

That is over 600 Khz..Way the H##L over anything we can possibly hear..

So, if we can discriminate 1.5 uSec shifts, why do we limit testing to 20Khz?

As I said, the article raises some very important questions.

Cheers, John

But, did the article use music or test tones? Test signals are much more sensitive to detection than music is that is constantly shifting, masking changing.

[mtrycraft]

Thanks Mtry,

just some comments/questions. The 0.2 µs discrimination point is not between frequencies but "between ears", thus binaural. The audible limit for phase deviation for pulses with respect to frequency and time is in the 1-2 ms region, according to the litterature. The implication of this article for cables should be minimal, except where cables cause differential deviations in phase between channels (?)

T

Plus, I don't think they used music which is much more difficult to discriminate than test signals to detect threshold levels as is the practice in such research, use th emost sensitive signal for detection of thresholds.

There was a phase shift test published in Audio or some such early mag, that showed people couldn't detect phase shift of many cyles with music, I believe. I need to dig it up and pass it on?

[mtrycraft]

For a complex musical waveform, if a human is keying on a 2Khz signal, trying to identify the location in space, the rest of the audio signal may be introducing a jitter, or some other phenom similar to it, to aid in lateralization..
Cheers, John

But complex music makes detection vastly more difficult than test tones as it is shifting constantly, not isolated as in test tones. And, you are faced with the masking effects too. So, unless you isolate that 2kHz in a way without the others bothering your attension, It will be most difficult.
That may be the reason why no differtences under bias controlled listeing has been reported so far.

Same principle in detecting JND levels with test tones and music, or distortion.

[Thomas_A]

I still don't understand why there is a problem with the system as long as there is a symmetry between channels (same group delay).Of course there is a continuous change in the complex signal, and it is not "constant" over time between channels, but I can only see systematic error which is unequal between channels, e.g. 1 metre and 20 metre cable, which can be audible in this case. The phase shift that translates into group delay has been in several studies been around 1-2 ms in the 1-5 kHz range (with clicks, headphones).

Now as JNeutron indicates, I may confuse two different issues. I have spoken to a person working with recognition of speech and sound at the Royal Technical High-School, and he promised to give an opinon in this matter.

T

[mtrycraft]

I still don't understand why there is a problem with the system as long as there is a symmetry between channels (same group delay).Of course there is a continuous change in the complex signal, and it is not "constant" over time between channels, but I can only see systematic error which is unequal between channels, e.g. 1 metre and 20 metre cable, which can be audible in this case. The phase shift that translates into group delay has been in several studies been around 1-2 ms in the 1-5 kHz range (with clicks, headphones).

Now as JNeutron indicates, I may confuse two different issues. I have spoken to a person working with recognition of speech and sound at the Royal Technical High-School, and he promised to give an opinon in this matter.

T

It's good to know talented people

Even if the two channels have a small difference, the delta between the two woul dhave ot be approaching the tresholds which would mean that one would be way off from the other, maybe unlikely.
But, in recordings, you have both left and right channel information in each channel but at different levels and maybe even in phase to give you better soundstage presentation. There is no pure left and right signals only.
I'd like to see someone localize an instrument in a band, blind, to that level of accuracy consistently in recorded music.

[Sealed]

If we are talking about “source” jitter, you would be surprised at how much a bit of jitter will affect sound. Just updating the original cd clock in a Rotel RCD-855 (circa 1991) to a new clock made a big difference. The old clock was something to the effect of low-millisecond jitter, much like the threshold stated in that test. The new clock was well into the nanosecond area, and specified a noise floor -135db +/- (vs -112db for the old clock) in reality, we are talking a very short rise time difference--but it was really obvious sounding.

As to “jitter” or smear, some fancy cables (or poorly built ones) can smear a signal on a time basis. I encountered this with RS gold cables. Not all of the RS cables are like this, but I had a batch from a poor run. The soldering was from the “bigger the blob the better the job” school, and QC missed these.

Even compared to a set of properly built RS golds, there was a big difference in audible effects. The poorly done batch sounded veiled and closed in. The properly built batch were much cleaner.

MIT has cables with components in line. These components do have a time-smear effect almost like a cheap crossover. Some exotic cables use exotic designs, and various insulation and conductive materials. Van Den Hul uses carbon fibre, which is a poor conductor and equates to adding a resistor inline with a component.

Plain AWG 12 oxygen free copper, with unterminated ends (direct wire connect of a short run) has a very low resistance, and very little chance of time-based smear.

[jneutron]

But complex music makes detection vastly more difficult than test tones as it is shifting constantly, not isolated as in test tones. And, you are faced with the masking effects too. So, unless you isolate that 2kHz in a way without the others bothering your attension, It will be most difficult.
That may be the reason why no differtences under bias controlled listeing has been reported so far.

Same principle in detecting JND levels with test tones and music, or distortion.

Agreed. And it may be the added non correlating musical information that provides the jitter related stimulus which allows for lateralization at that incredibly small time regime.

The bottom line with the Nordmark study, IMO, is the fact that he came up with a modification to a test that increased the human lateralization threshold capability an order of magnitude. That, by just introducing a non random, bipolar jitter into the signal.

What is the most interesting for me is that humans (well, three at least) were capable of discerning 1.5 uSec differences for lateralization. That is over 10 times previous indicators.

Non repeatability in DBT's may simply be a matter of understanding what component of the music is causing the jitter..be it overall spl, time related fatigue, whatever. This study points the way towards perhaps coming up with a test regimen that accentuates our lateranization capability.

Boy, I gotta tell ya..if this study is accurate, my load resistor is toast...I designed it for 1 to 2 Mhz operation with minimal phase shift at 4 ohms...Now I may have to re-think it, and make it go out to 20 to 50 Mhz..

Addressing other posts, without adding quotes...

Mtry: they used test tones..In fact, it was funny reading about how they used a nova 1200 minicomputer to create the waveforms..

Mtry: Nordmark is concerned only with lateralization, not single source phase shifts.

Thomas A: 1 to 2 ms phase shift was addressed..If you look at figure 3, the upward pointing curve represents zero jitter....that is the curve you are speaking of with the other studies..and as you can see, it rapidly loses all sensitivity at about 1.2 Khz, consistent with the other studies..

If a pure mono signal is used on both channels, then I agree with you...but, stereo operation is not that case..both channels of the amp will cross quadrants at different times, and that can possibly be a source of temporal shifts in the 2 uSec range. The added complication of a dynamic load with energy storage, and a series inductance in the way add complexity to the issue.

Unfortunately, to test for that requires a load resistor capable of no phase shift at those frequencies, the data would indicate half a megahertz...I would recommend 10 to 20 times the bandwidth for accuracy..

Mtry: the delta doesn't have to be off more than 2 uSec, which is not far at all.. I agree, localization of an instrument to that level (we're actually talking about an inch or so for 2 uSec) would be a good test.. But, given anecdotal accounts, I'd be happy if someone could do so with some complex test tone and a foot or so...

Sealed: clock jitter of a millisecond???? My lord...I didn't think that was possible..the crystals I remember had nano level stuff..no wonder you heard it..even a 555 circuit is better than that..

RS? I've encountered quality issues in the past with their lines..There is no way a solder "blob" caused what you describe. Did you notice if it was a cold joint? Or was the blob there because the solderability of the connector was very poor? Other things I would look at first: were the materials from the same production lot..was the DC the same...was the cable made exactly the same, IOW, at the manu level, was the cabling done on the same machine, same DC thickness, same L-C characteristic? There's way too many things associated with the making of the wire that will impact the lumped parameters...ascribing a blob to sound signature is, shall I say, way too premature, given all the other aspect of manufacture that may not have been under adequate control (most of which you and RS will be unaware of).

Oh, as a side note: the time frame we are talking about here is WAY WAY into the skin effect realm for normal conductors..funny, ain't it?

Cheers, John

[Sealed]

Sealed: clock jitter of a millisecond???? My lord...I didn't think that was possible..the crystals I remember had nano level stuff..no wonder you heard it..even a 555 circuit is better than that..

RS? I've encountered quality issues in the past with their lines..There is no way a solder "blob" caused what you describe.
--Yes, it did...indirectly I resoldered the connections, and the sound cleaned up dramatically. The cheap solder, and bad soldering job (cold solder joint) was the culprit. I used some 4% silver content solder. Worked like a champ.

Did you notice if it was a cold joint?
--Yes, that was the bad soldering job (as above)

...ascribing a blob to sound signature is, shall I say, way too premature, given all the other aspect of manufacture that may not have been under adequate control (most of which you and RS will be unaware of).
-- This was just a bad connection basically. All kinds of nasty audible things happen from bad solder jobs.


Oh, as a side note: the time frame we are talking about here is WAY WAY into the skin effect realm for normal conductors..funny, ain't it?
--I never much subscribed to skin effect in audio, especially with short runs.

Cheers, John

The 855's original clock is *MUCH* less accurate than modern clocks. It is a great testbed for the effects of jitter before and after. The cd player itself has many good features, like blackgate caps, and a decent transport, but suffers from poor p/s placement, shielding and an innacurate clock. If a modern clock were say .005ns, this clock was something like 500ns or even slower. I forget, but I can dig up that info this week. The old clock was many times less accurate.

[jneutron]

The 855's original clock is *MUCH* less accurate than modern clocks. It is a great testbed for the effects of jitter before and after. The cd player itself has many good features, like blackgate caps, and a decent transport, but suffers from poor p/s placement, shielding and an innacurate clock. If a modern clock were say .005ns, this clock was something like 500ns or even slower. I forget, but I can dig up that info this week. The old clock was many times less accurate.

Only for upgrading clocks with millisecond jitters...that statement is at present unsupported when the origional clock has 10 nano or so jitter..you're replacing a skateboard with a hypersonic plane...

You caught me when you included comments bolded within the quote..but I eventually saw them..

RS? I've encountered quality issues in the past with their lines..There is no way a solder "blob" caused what you describe.
--Yes, it did...indirectly I resoldered the connections, and the sound cleaned up dramatically. The cheap solder, and bad soldering job (cold solder joint) was the culprit. I used some 4% silver content solder. Worked like a champ.

jn:
I fear I was not concise in my statement..I was talking about the blob as a mass of metal, and that the geometry, mass, or anything like that does not cause time smearing..So, ya got me...

...ascribing a blob to sound signature is, shall I say, way too premature, given all the other aspect of manufacture that may not have been under adequate control (most of which you and RS will be unaware of).
-- This was just a bad connection basically. All kinds of nasty audible things happen from bad solder jobs.

jn:
That was why I mentioned the solderability of the connector. You'd be surprised that some will ascribe to a solder blob some "mass", or other equally weird attribute that deflects the bad electrons, or makes them semi-superconducting...from your post, you obviously are not one of them.

Oh, as a side note: the time frame we are talking about here is WAY WAY into the skin effect realm for normal conductors..funny, ain't it?
--I never much subscribed to skin effect in audio, especially with short runs.

jn:
If the Nordmark paper has validity, it may be necessary to rethink that position..

If wire bandwidth of half a megaHertz is required to quash time errors on the order of a coupla microseconds, then the internal 15 nanohenry per foot conductor inductance takes on a new meaning, as does it's loss as skin occurs..

Cheers, John

[Thomas_A]

JNeutron: So how about speakers? Isn't the speakers even a more critical subject in this matter than cables? I may have missed something, but I will come back into this discussion after some more discussion with other people. I couldn't find J. Nordmark at the Institute where I work (Karolinska Insitute), but I will try to get in touch with some people on the department, if they have any comments to the paper.

T

[Sealed]

Only for upgrading clocks with millisecond jitters...that statement is at present unsupported when the origional clock has 10 nano or so jitter..you're replacing a skateboard with a hypersonic plane...

You caught me when you included comments bolded within the quote..but I eventually saw them..

RS? I've encountered quality issues in the past with their lines..There is no way a solder "blob" caused what you describe.
--Yes, it did...indirectly I resoldered the connections, and the sound cleaned up dramatically. The cheap solder, and bad soldering job (cold solder joint) was the culprit. I used some 4% silver content solder. Worked like a champ.

jn:
I fear I was not concise in my statement..I was talking about the blob as a mass of metal, and that the geometry, mass, or anything like that does not cause time smearing..So, ya got me...

...ascribing a blob to sound signature is, shall I say, way too premature, given all the other aspect of manufacture that may not have been under adequate control (most of which you and RS will be unaware of).
-- This was just a bad connection basically. All kinds of nasty audible things happen from bad solder jobs.

jn:
That was why I mentioned the solderability of the connector. You'd be surprised that some will ascribe to a solder blob some "mass", or other equally weird attribute that deflects the bad electrons, or makes them semi-superconducting...from your post, you obviously are not one of them.

Oh, as a side note: the time frame we are talking about here is WAY WAY into the skin effect realm for normal conductors..funny, ain't it?
--I never much subscribed to skin effect in audio, especially with short runs.

jn:
If the Nordmark paper has validity, it may be necessary to rethink that position..

If wire bandwidth of half a megaHertz is required to quash time errors on the order of a coupla microseconds, then the internal 15 nanohenry per foot conductor inductance takes on a new meaning, as does it's loss as skin occurs..

Cheers, John

That's kind of like an except from "The vagina monologes" or another soliloquy. I did not have time to type it out like that. You seem to amuse yourself by putting in your own interpretation, so I leave this thread to you.

[jneutron]

That's kind of like an except from "The vagina monologes" or another soliloquy. I did not have time to type it out like that. You seem to amuse yourself by putting in your own interpretation, so I leave this thread to you.

Actually, I just cut and pasted the stuff using control C and Control V. The typing I had to do was just where I made comments..It was more difficult trying to figure out how to make my comments visible in the whole thing..

I am however, definitely amused by your statement that I am putting in my own interpretation, as I have not, nor do I intend to do such..as I said... I felt that I had not clearly stated something..

Your input within the thread, I welcome...you're misinterpretation of intent is not..perhaps you'd be better off remaining on topic..and leaving your self serving comments checked at the door..

It is not a real stretch to think that a 1 millisecond jitter could affect sound reproduction (although I'd be more inclined to think that was a typo on the manu's part, and that it was 1 microsecond), nor that a cold solder joint could affect sound reproduction..again, not a real stretch.

The real stretch is that humans can distinguish 1.5 usec timeshifts.. Not a real stretch is how people divert as a defense mechanism..Your use of such tactics was unwarranted, for you to do so indicates you've probably mis-interpreted my statements..

Cheers, John

[jneutron]

JNeutron: So how about speakers? Isn't the speakers even a more critical subject in this matter than cables? I may have missed something, but I will come back into this discussion after some more discussion with other people. I couldn't find J. Nordmark at the Institute where I work (Karolinska Insitute), but I will try to get in touch with some people on the department, if they have any comments to the paper.
T

For overall sound stuff, yah..

In theory, the speakers both should do the same thing in response to the same signals. I've not considered the fact that a speaker may have some kind of weird time shifted stuff in any of my wirespeak, and I am in no way capable of really getting into that..Maybe some ESL guy, like Chuck, could address the finer points of speaker response stuff..But not me..

I will only deal at this point with pure resistive load stuff, without introducing the huge variance of speakers..

That would be really nice if you find some of Nordmark's peers. Since I only found out about this paper as a result of Jon Risch, who sent a different paper to me for my information, I cannot say if Nordmark's test regimen has been duplicated or refuted. And the cable vendor (if I recall correctly) that cited Nordmark may not provide citations that would go against it, or may not even be aware of papers that refuted it, if so..

Cheers, John

[Sealed]

The real stretch is that humans can distinguish 1.5 usec timeshifts.. Not a real stretch is how people divert as a defense mechanism..Your use of such tactics was unwarranted, for you to do so indicates you've probably mis-interpreted my statements..

Cheers, John

Nah, I am not being defensive, insulting, or anything more than cheeky. Press on this thread without me.

Beers...I mean...oh skip it.

Carry on...

[jneutron]

Nah, I am not being defensive, insulting, or anything more than cheeky. Press on this thread without me.

Beers...I mean...oh skip it.

Carry on...

My apologies....I obviously misunderstood your intent..I really try not to mis-interpret anyone, so perhaps I'm overly sensitive to the accusation..

..wish I could share a beer with you..I'm allergic to gluten. Boy, do I miss a cold one..destined forever to wine, sake, and martini's with Chopin..ah, the inhumanity of it all..

Cheers, John

[pctower]

My apologies....I obviously misunderstood your intent..I really try not to mis-interpret anyone, so perhaps I'm overly sensitive to the accusation..

..wish I could share a beer with you..I'm allergic to gluten. Boy, do I miss a cold one..destined forever to wine, sake, and martini's with Chopin..ah, the inhumanity of it all..

Cheers, John

Allergic to gluten? Be grateful. I'm allergic to alcohol. It stimulates an over-active elbow which results in frequent and persistent movement of the bottle to wide-open mouth.

Can you imagine Chopin with tea? Inhumanity knows no bounds!

[mtrycraft]

If we are talking about “source” jitter, you would be surprised at how much a bit of jitter will affect sound. Just updating the original cd clock in a Rotel RCD-855 (circa 1991) to a new clock made a big difference. The old clock was something to the effect of low-millisecond jitter, much like the threshold stated in that test. The new clock was well into the nanosecond area, and specified a noise floor -135db +/- (vs -112db for the old clock) in reality, we are talking a very short rise time difference--but it was really obvious sounding.

As to “jitter” or smear, some fancy cables (or poorly built ones) can smear a signal on a time basis. I encountered this with RS gold cables. Not all of the RS cables are like this, but I had a batch from a poor run. The soldering was from the “bigger the blob the better the job” school, and QC missed these.

Even compared to a set of properly built RS golds, there was a big difference in audible effects. The poorly done batch sounded veiled and closed in. The properly built batch were much cleaner.

MIT has cables with components in line. These components do have a time-smear effect almost like a cheap crossover. Some exotic cables use exotic designs, and various insulation and conductive materials. Van Den Hul uses carbon fibre, which is a poor conductor and equates to adding a resistor inline with a component.

Plain AWG 12 oxygen free copper, with unterminated ends (direct wire connect of a short run) has a very low resistance, and very little chance of time-based smear.

Of course you establisged all these testable claims through bias controlled listening? And, has been so duplicated by others? No? Sorry, just more wishfull speculations.

[jneutron]

Of course you establisged all these testable claims through bias controlled listening? And, has been so duplicated by others? No? Sorry, just more wishfull speculations.

If he had a clock with jitter in the milliseconds, I don't think anybody is going to dispute his claim that he could hear it..it's kinda like riding along the railroad tracks on a ten speed, with your head on the handlebars..

And I'm sure if he had a lousy solder joint, nobody would dispute that he heard it..

Only here:Plain AWG 12 oxygen free copper, with unterminated ends (direct wire connect of a short run) has a very low resistance, and very little chance of time-based smear. can I have an issue with...and only the "little chance of time based smear".

As, the human ear would only hear a r-l change, not a per channel one..

My question would be: how does one measure a time smear with the ears? What is it? What frequencies affected..you know, the standard "how would one measure it" questions.

Chopin Vodka in tea? Eeeeeewwwww...

Perhaps some tea bags with the blue cheeze filled olives? Make it quicker, I'd think..

HI Phil..

Well guys, back to the origional topic...

I've heard neither hide nor hair from Bruno..Not sure whether he just dissed me, has measured what I described and is running to the patent office, has tried and failed to find anything so has dismissed me as an unknowledgeable moron, has gone on vacation, or has been committed to an asylum for even humoring me..

I was hopin he'd try it, as the next step is to show how speaker wire geometry and L-C parameters will introduce phase shift at the amp input stage..

Not done yet, but it's startin to look like something at least..

Cheers, John

[mtrycraft]

If he had a clock with jitter in the milliseconds, I don't think anybody is going to dispute his claim that he could hear it..it's kinda like riding along the railroad tracks on a ten speed, with your head on the handlebars...

Cheers, John

If in the millisecnd range then yes. I have a difficult time accepting such a high jutter from a clock when all I hear about is in the nanosecond range.


And when you are finished, then back to the skin effect experiment?

[jneutron]

If in the millisecnd range then yes. I have a difficult time accepting such a high jutter from a clock when all I hear about is in the nanosecond range.

Yah, that's why I questioned the milli as a typo, I would believe micro...

And when you are finished, then back to the skin effect experiment?

Absolutely.

I have learned a lot since first embarking on the skin effect stuff. Ways to make the load resistor much lower in inductance (although even the one I built already is far below my measurement capabilities). I have lost the ability to measure the loads reliably anymore using any commercial inductance meter, so am working out a scheme to measure them using the HP 3225A synthesizer, and looking for the V/I phase shift. Unfortunately, it only goes to 60 Mhz, so I'm afraid I'll just have to live knowing I can't meet the expectations of high end audio...:-) And, I'm considering making a pulse welder out of some big caps, lots of mosfets, and some timing circuits, as making the previous load required soldering 39 resistors to a tube simultaneously...one shot welding with some fixturing will allow me to easily duplicate the final design.

That darn Nordmark paper...pushing my test requirements up over a Mhz...oh well..

Oh, BTW...Bruno thought it was my turn to talk, we were both waiting for e-mails..

He also has a large queue, so looks like I better get that attic finished soon..

Cheers, John

[mtrycraft]

Yah, that's why I questioned the milli as a typo, I would believe micro...

Absolutely.

I have learned a lot since first embarking on the skin effect stuff. Ways to make the load resistor much lower in inductance (although even the one I built already is far below my measurement capabilities). I have lost the ability to measure the loads reliably anymore using any commercial inductance meter, so am working out a scheme to measure them using the HP 3225A synthesizer, and looking for the V/I phase shift. Unfortunately, it only goes to 60 Mhz, so I'm afraid I'll just have to live knowing I can't meet the expectations of high end audio...:-) And, I'm considering making a pulse welder out of some big caps, lots of mosfets, and some timing circuits, as making the previous load required soldering 39 resistors to a tube simultaneously...one shot welding with some fixturing will allow me to easily duplicate the final design.

That darn Nordmark paper...pushing my test requirements up over a Mhz...oh well..

Oh, BTW...Bruno thought it was my turn to talk, we were both waiting for e-mails..

He also has a large queue, so looks like I better get that attic finished soon..

Cheers, John

Great update. I am glad one of you emailed again instead of waiting to the end of times

I will be satisfied with a low fi report, 60mHz is fine with me. You can quote me on it too

Don't you have some lab quality measuring gear at work? How about the Standards Org. Tell them you need help

[jneutron]

Great update. I am glad one of you emailed again instead of waiting to the end of times

I will be satisfied with a low fi report, 60mHz is fine with me. You can quote me on it too

Don't you have some lab quality measuring gear at work? How about the Standards Org.

When my audio desired mesh with lab work, I don't have any issues with using their equipment. Case in point: measuring very low inductance, as we had an app at that time needing rather good accurate measurment, and I needed to upgrade the test setup.

Tell them you need help

How did this discussion suddenly turn towards psychiatry??

Besides, If you met some of the researchers, scientists, and physicists here, you would understand how "Doc Brown", from back to the future, would not considered out of place..so my having a conversation with those voices inside my head are part and parcel...

Cheers, John

[Thomas_A]

Mtry,

sorry I delayed my answers to you. I am still waiting for a replies from others in this matter. I have passed the question also to the Swedish Audio-Techincal Society, but it might take a while before the question is published in the MoLT journal.

Off-topic

There is a new reference CD player (or actually a DVD player) that has passed through many "extreme" listening tests by SATS but its DVD capability is not top notch (Pioneer DVD 59AVi in the US, 868 in Europe). Another cheap DVD player, Panasonic DVD-RP82, appears to be quite free from image distortions as tested by the benchmarks made by Home Theather and High Fidelity. These benchmarks, are they discussed on Audioreview?

Benchmark

T

[mtrycraft]

Mtry,

sorry I delayed my answers to you. I am still waiting for a replies from others in this matter. I have passed the question also to the Swedish Audio-Techincal Society, but it might take a while before the question is published in the MoLT journal.

Off-topic

There is a new reference CD player (or actually a DVD player) that has passed through many "extreme" listening tests by SATS but its DVD capability is not top notch (Pioneer DVD 59AVi in the US, 868 in Europe). Another cheap DVD player, Panasonic DVD-RP82, appears to be quite free from image distortions as tested by the benchmarks made by Home Theather and High Fidelity. These benchmarks, are they discussed on Audioreview?

Benchmark

T

Great, no problem. You know where to email too I am curious what the horse has to say, coming from the horses mouth on that paper.
I have just been reading a link probably at HT section about that Pioneer player problem.

[mtrycraft]

How did this discussion suddenly turn towards psychiatry??

Besides, If you met some of the researchers, scientists, and physicists here, you would understand how "Doc Brown", from back to the future, would not considered out of place..so my having a conversation with those voices inside my head are part and parcel...

Cheers, John

You misunderstood me, obviously. The standards org was the head government bureau of standards that I was trying to imply didn't work That you need to measure very, very low inductance. Perhaps they have some such instruments?