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Old 30th November 2012, 01:03 PM   #30491
Jay is offline Jay  Indonesia
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Default What is the difference between copper and silver, technically?

I have never measured cables but my silver cable sound different with my copper cable. Both products came from the same manufacturer. The build quality is very similar and I use 2m from amp to speaker, and I also use them inside speaker enclosures.

Inside my speaker I have decided to use copper on tweeter and silver on woofer. I couldn't decide which one I like more. The silver cable is like carbon composite, the copper cable is like metal film. I think I can understand why there is cable made from a mix between copper and silver.
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Old 30th November 2012, 01:08 PM   #30492
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Originally Posted by john curl View Post
They often became the CTC Blowtorch owners, not some engineer who would rather do it himself, or whatever.
May-we suppose people who became CTC Blowtorch owners to be outrageous rich people, believing that more expensive, better it is ?
I do not make any criticism about the real quality of your preamp i never listened to, when you refuse to provide schematic, and when you refuse to provide measurements, so i'm just VERY suspicious about-it.
And, John, by the way, more you talk about burning cables, and black magic, more i'm suspicious about you.

At the end, the only thing I am sure about the Blowtorch, is that it is not worth the price, because its price is a nonsense to me.
Quote:
Originally Posted by john curl View Post
Well, I hear cable differences. My colleagues have been known to be VERY SENSITIVE to cables and such. All that I can really attest to is in the listening.
This is not productive, on my point of view. Imagine a circuit witch will oscillate with a 100pf charge. Add a 100pf cable ? Conclude something about "hearing a cable sound difference" ?
Most of us agree that cables differences are based on the interaction of their electrical characteristic on the active devices around. And , when we want to tune something a cable can modify, it is better to do-it active devices side. So simple.
And, please, don't suppose we are all deaf and running poor systems. You could be VERY surprised, and may-be shamed.
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Last edited by Esperado; 30th November 2012 at 01:21 PM.
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Old 30th November 2012, 01:24 PM   #30493
PMA is offline PMA  Europe
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Quote:
Originally Posted by john curl View Post
Well, I hear cable differences. My colleagues have been known to be VERY SENSITIVE to cables and such. All that I can really attest to is in the listening.
For cables to make any serious difference, the rest of the audio system has to be at just as high quality, or it is a waste of time.
I am supporting this.
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Old 30th November 2012, 02:04 PM   #30494
SY is offline SY  United States
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Quote:
Originally Posted by PMA View Post
I am supporting this.
Faith is a lovely thing. I prefer data and evidence.
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Old 30th November 2012, 02:15 PM   #30495
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Originally Posted by Pano View Post
I'm searching, but not finding. Any clues?
I will find it for you, it has been a while.

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Originally Posted by scott wurcer View Post
OK optical source to amp, if you have bits anywhere in the path no need for any new complaints.
Yabut, don't bend the fiber too much..tight bends and some of the bits may fall out, they are going pretty fast you know...

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Originally Posted by kgrlee View Post
Neutron, I think you have said you have conducted extensive research on aural perception.

Can you tell us when & where?

I'm interested cos I have some small experience of this but am a bit rusty cos a beach bum for more than a decade.
Sy below has it rather accurate. There is literature out there which actually provides 1.5 uSec testable and repeatable ITD discrimination out to 12 Khz with dither, and 5 uSec to about 1.5khz without. Not suggests, but also lateralization not localization.

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Originally Posted by SY View Post
I'd still like him to generate some test signals digitally to demonstrate his hypothesis. I don't think he's correct, but the proof is in the listening.
I do not have the necessary materials to do this digitally.

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Originally Posted by Bob Cordell View Post
jn,

This discussion has turned into a waste of time. Those reading it are smart enough to make up their own minds.

Bob
I harped on you for several reasons (my apologies).

First, I decided last night to stop tiptoeing around the elephant in the room. You are one of participants here that I set the standards bar very high for as a consequence of my high regard for your expertise. My expectations of you do not include diversion or obfuscation.

Second. The t-line analysis I have presented is not rocket science. In point of fact, it was an analysis presented to the students in the second lecture of my E/M field theory course. Anybody who took this course and paid attention knows how to do this. Personally, the first two lectures were extreme eye openers for me, as they were my first introduction to signal propagation in wires. DF96 correctly points out the more refined t-line equations, but inclusion of those elements makes the problem WORSE, not better. IOW, it doesn't invalidate the result, but sets the result as a lower limit.

I have extended that analysis in several ways. A t-line will carry a signal at it's prop speed ONLY with the signal V/I relationship of the cable, and that propagating signal will have equal inductive and capacitive energy storage in the wake of the leading edge. A 100 ohm wire pair does not instantly know that the load is 8 ohm, so the signal travelling down the line cannot support 8 volts per amp, it supports 100 volts per amp.

Your "speaker tolerances are far more important and swamp any such delays" is either obfuscation on your part, or you simply do not understand. Read the next paragraph slowly please.

I have a pair of cabs with eminence delta pro 12's, selenium D205TI's, first order LP to woofer at 3Khz, 3rd order 5khz HP to tweeter, 5% tolerance all caps/inductors.....and when I run both cabs off the same amp channel, I "see" a central image which my brain interprets as the source of the sound. This despite absolutely NO tolerance matching, no driver matching, no phase concerns, no level matching..nothing. These speakers were slapped together with NO regard to any level of quality and are abused as PA speakers. And yet, they are absolutely capable of providing images despite having little engineering involved. The only engineering I used was the use of an overly tight cabinet such that the very small back volume helped prevent woofer overexcursion during a 145+ dB SPL pulse from a hydrogen/oxygen explosion. I say 145+ because it was measured 20 feet from the source, whereas the speakers were 10 feet away. And I made sure the amp (QSC RMX 1450) was on and connected so that it also stiffened the cone against the pressure wave.

You are welcome to run off claiming it's useless, I harped on you to give you that "out". Or, you could continue contributing. Your choice.

If you choose to continue, I recommend you learn enough t-line theory to understand the analysis. I unfortunately lost the testbook I used back in '74 or '75, perhaps somebody else can chip in with a reasonable text...certainly not Jackson or Becker...

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Originally Posted by DF96 View Post
However, all this is negligible when compared with what happens in loudspeakers.
Read above.
jn

Last edited by jneutron; 30th November 2012 at 02:29 PM.
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Old 30th November 2012, 02:42 PM   #30496
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Originally Posted by SY View Post
Faith is a lovely thing. I prefer data and evidence.
Listening tests performed are the evidence to me. I do not care we do not have an appropriate measuring method yet. Once it will appear. Experiment is almost always ahead theory.
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Old 30th November 2012, 02:49 PM   #30497
Bonsai is offline Bonsai  Taiwan
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Originally Posted by john curl View Post
Well, I hear cable differences. My colleagues have been known to be VERY SENSITIVE to cables and such. All that I can really attest to is in the listening.
For cables to make any serious difference, the rest of the audio system has to be at just as high quality, or it is a waste of time. It would be like putting the highest quality tires on a VW Beatle. It would work, but the cost of the tires would not be offset by any real improvement. Put quality tires on a Porsche, and see what happens, especially if the tires on the vehicle were below Porsche recommendations for some reason. It can be the same with wires.
Personally, I don't like to do comparative listening tests with wires or just about anything else, but I have heard the differences when I attended a serious trial.
Who does these trials? OH, engineers, physicists and MD doctors in my general experience. The MD's because they are some of the VERY FEW people who can afford the best all the way down the line. I have met perhaps a dozen of them . They often became the CTC Blowtorch owners, not some engineer who would rather do it himself, or whatever.
There are other, more rational explanations.

The amplifiers driving these cables are intolerant of the load for one.
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Old 30th November 2012, 02:55 PM   #30498
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Trivial explanations like 'oscillation' or change in capacitance are pointless. We know how to check for these things, we also know how to protect an audio product from being sensitive to small changes like capacitance. It is called 'engineering'. '-)
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Old 30th November 2012, 03:04 PM   #30499
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Originally Posted by Pano View Post
I'm searching, but not finding. Any clues?
http://www.belden.com/docs/upload/Pr...les-Part-1.pdf

If you look at page 1, they show a graph on the right hand side.

The article is written about coax because they make coax. The derivations still apply to parallel line t-lines, but some entities like capacitance and inductance require different equations due to geometry.

Note in the graph, which I assume is about a 75 ohm cable (can't tell exactly from the vertical log axis), at .001 Mhz, or 1Khz, the impedance is about 200 or 300.

My derivation assumes "75" constant, DF96 is trying to include the rise with LF.

The analysis I provide considers the load mismatch, so if the load is 4 and MY line is 75, lots of reflections will be required before the 4 ohm load sees the current the supply is supposed to provide. If we adopt DF96's numbers, the mismatch is no longer 75 to 4, but 250 to 4. That requires even more reflections. What is worse, if we frequency limit the signal, the transit speed of the line is too fast with respect to slew rate, so we cannot see the effect clearly. I already pointed out the difficulty of seeing a 10 uSec delay in a 1Khz signal especially in a low impedance system.

Use of a step transition to examine system time response is a standard engineering technique. I use it whenever I need to program or tune any of my motion control platforms.. With digital and analog circuits, it's not so clearcut as the hf component violates digital and can broadcast analog.. With wires and simple resistive circuits, it's great.

jn

Last edited by jneutron; 30th November 2012 at 03:07 PM.
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Old 30th November 2012, 03:11 PM   #30500
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Esperado, I hate to ask this, but do you know of Yves Benard Andre, once a lecturer at the Ecole Polytechnique in Paris? Also a consultant on wiring for the Mirage fighter plane.
His company went by the name YBA.
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