Cable Distortion Measurements: Part Deux

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mefinnis said:
Sorry, I am an examiner for the Australian+NZ College of Anaesthetists. I work fulltime in Intensive Care and spend a lot of time in teaching/training.

Ah, thanks. Was just making sure it wasn't something like accident/injury attorneys or other lower forms of life. :)

While the finer engineering points here pass me by, I have a deep-seated interest in scientific method.

Yes. And you don't need to be an engineer to apply it.

se
 
diyAudio Senior Member
Joined 2002
Hi,

You have heard of 'dirty contacts' haven't you? Well, I seem to be able to measure them.

Sure can and even my ears can...more to the point it seems that some here are missing at least ten pages of electronics industry and I don't mean you John C....

I work with mainframes and vaxes and contact reliability is of the utmost importance here...The same contact enhancing products are out there for eveyone to buy often in dilluted sollutions.
They work, preserve and protect...Thank god.

These same products are also used in aersospace applications and an audio derrivative was marketed many years ago under the name "Tweak".

Regarding break in of cables, well that's the whay we call it but has it occured to anyone that there may be a rearrangement of electron allignment occurring during this period? I could be wrong with my guesses but I sure do hear it...Someting's happening...

Maybe something for a scanning electron microscope too...It seems just the perfect tool to solve many pending questions.

I'm starting to find nanoelectronics a very interesting topic...
Let me rephrase that: I'm starting to be aware that much of what I've learned in audio has it's roots in nanoelectronics.

Fascinating stuff...;)
 
Steve Eddy said:
When it comes to getting at the truth of something, let's keep things impersonal. Something either is the way it is or it isn't. And whichever way it ends up being, it doesn't end up being that way because someone said it is or it isn't. Or because someone was right or someone was wrong.

se

Hello -

I disagree with you on this. I think it is extremely useful to know when someone has changed their point of view. For example, after reading Putzeys' reply that you quoted a few posts up, I agree with him point by point, and my previous supposition was wrong.

After I make a public statement like this, there is no ambiguity by any of the readers of this thread that we are all heading in the same direction, and that nobody is surreptitiously "dragging their feet".

On a separate topic but related topic, I would still like to know the details of Putzeys' setup. There are still a lot of important things being left out of his results. For example, how many measurements were averaged, and what adapters did he use, et cetera?

If I can figure out how to make my AP average multiple measurements, I will repeat his tests on my machine. If not, I will try the test on a colleague's System Two.

Charles Hansen
 
Originally posted by Charles Hansen I disagree with you on this. I think it is extremely useful to know when someone has changed their point of view. For example, after reading Putzeys' reply that you quoted a few posts up, I agree with him point by point, and my previous supposition was wrong.
SE, I would tend to agree with Charles on this. From his opening discussion he clearly has experience with this type of equipment and for him to confirm that Bruno is "correctly aligned" useful for the "fringe dwellers" like myself.

There are no "points" attached to his comment, excepting that he has defined himself as someone who will examine the evidence before him and is prepared to accept/acknowledge when he is in error.

I would rather work with this individual than the man who is "always right" any day!

Another favourite quote: I thought I was wrong once, but then I realised I was mistaken ....

cheers
mark
 
Charles Hansen said:
I disagree with you on this. I think it is extremely useful to know when someone has changed their point of view. For example, after reading Putzeys' reply that you quoted a few posts up, I agree with him point by point, and my previous supposition was wrong.

After I make a public statement like this, there is no ambiguity by any of the readers of this thread that we are all heading in the same direction, and that nobody is surreptitiously "dragging their feet".

Fair 'nuff.

On a separate topic but related topic, I would still like to know the details of Putzeys' setup. There are still a lot of important things being left out of his results. For example, how many measurements were averaged, and what adapters did he use, et cetera?

If I can figure out how to make my AP average multiple measurements, I will repeat his tests on my machine. If not, I will try the test on a colleague's System Two.

The power averaged plots were made using 256 averages. I don't know how many averages he used for the synchronous averaged plots. I just EMailed him and I'll let you know as soon as I hear back.

se
 
mefinnis said:
SE, I would tend to agree with Charles on this. From his opening discussion he clearly has experience with this type of equipment and for him to confirm that Bruno is "correctly aligned" useful for the "fringe dwellers" like myself.

There are no "points" attached to his comment, excepting that he has defined himself as someone who will examine the evidence before him and is prepared to accept/acknowledge when he is in error.

Fair 'nuff. I just couldn't help cringing at the "Steve Eddy was right" comment.

Another favourite quote: I thought I was wrong once, but then I realised I was mistaken ....

:D

se
 
diyAudio Senior Member
Joined 2002
Hi Jon F,

However, why would parallel wires give more problems?

The size of the problem is trivial but just think about the extra insulating material you're hosting and for what good reason?

Add to that extra capacitance and so on...Not harmful per se in some situations but I can't even second guess the application you have in mind.

I understand your logic drawn from Eric's but I'm afraid I can't support it and this way of putting wires in // wasn't what Eric had in mind...

Either way I don't feel it solves directionallity if that were such a problem at all.

Cheers,;)
 
diyAudio Senior Member
Joined 2002
Hi,

Could you explain to me what you mean by that? How does one "align" an electron?

'Fraid I can't..Not too sure what's going on, whether it's electrons, atoms, molecules or whatever....

We'll have to skip that for the time being as I just don't have anything acceptable to offer right now and I won't hold my breath either if I were you.

Let's see later if there's anything to it at all.

Cheers,;)
 
john curl said:
I find that 'moving targets' make sense. Let me explain to the rest of you.
You have heard of 'dirty contacts' haven't you? Well, I seem to be able to measure them. I start with some adaptors that I must use to make the test possible. I clean them at first, BUT over time they seem to get 'dirty' I clean them again, and the extra distortion goes away. Is this an impossible concept?

Not an impossible concept at all. But problems associated with dirty or otherwise poor contacts is something which is well-known.

What we're looking for is nonlinearity being produced by the wire itself.

You also have heard of 'break-in' of cables. It seems that when I find a particularly 'bad' cable, I tend to use it for testing more often, sometimes accidently leaving it in the machine running with a test signal for days. You might ask, am I not paying attention? Yes and no. Sometimes I turn off everything EXCEPT for my ST analyzer. It likes to be on all the time, and with something connected to it. If I forget to replace the test cable with a reference, the test signal will continue to flow through the cable until I go back, which might be days later. Just last week, I accidently left SE's steel leaded cable in the analyzer, overnight. Well, overnight was not enough to change it much, so I can still use it for testing.

And this is where a more systematic approach could be helpful.

Get two, brand new, unused, identical cables. Do a quick baseline measurement on both of them. Run one of them in for a time. Then measure both cables again.

se
 
fdegrove said:
Hi Jon F,



The size of the problem is trivial but just think about the extra insulating material you're hosting and for what good reason?

Add to that extra capacitance and so on...Not harmful per se in some situations but I can't even second guess the application you have in mind.

I understand your logic drawn from Eric's but I'm afraid I can't support it and this way of putting wires in // wasn't what Eric had in mind...

Either way I don't feel it solves directionallity if that were such a problem at all.

Cheers,;)

Okay, I know the detail of my circuit would be rather trivial to a lot of people, but here is one of my ideas (since it's good for everyone to contribute). I want to use a thermal epoxy to glue the components upside down (dead bug style) on a heatsinking material (maybe a good copper ground plane as the substrate). Then, I will wire the components point to point. Air dielectric, less capacitance. I like the idea of silver wire aiding heatsinking through the leads (okay, it will be just slightly better than copper...). I had already thought about doing this, before I read about JCarr also doing the point to point wiring. This made me think that it wasn't such a bad idea.

This should be in the other thread, but I'll remain with Frank's post.


JF
 
johnferrier said:
Okay, I know the detail of my circuit would be rather trivial to a lot of people, but here is one of my ideas (since it's good for everyone to contribute). I want to use a thermal epoxy to glue the components upside down (dead bug style) on a heatsinking material (maybe a good copper ground plane as the substrate). Then, I will wire the components point to point. Air dielectric, less capacitance. I like the idea of silver wire aiding heatsinking through the leads (okay, it will be just slightly better than copper...). I had already thought about doing this, before I read about JCarr also doing the point to point wiring. This made me think that it wasn't such a bad idea.

Are you actually needing the heatsinking? Otherwise, why not get some terminal posts and just do your point to point wiring without any glue? Are you primarily just wanting to eliminate circuit boards?

This should be in the other thread, but I'll remain with Frank's post.

Oh what the hell. It's nearly Christmas. :)

se
 
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