John Curl's Blowtorch preamplifier part III

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scott wurcer said:
Besides being total nonsense, why do you think people are confused?
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Why are people confused? That is a very good question - my topic is actually quite simple and I talk to a lot of people who are not confused at all. They are actively engaged in the question that is being raised: The topic is not about current drive, but what the current does under voltage drive. Perhaps look up the work by Hans van Maanen of Temporal Coherence and Menno Vanderveen and more. People are coming at this from various different angles, the subject is clearly bigger than one person. Again I reiterate that this is not a rehash of the on and off discussion of current drive, we have progressed beyond that old chestnut. This is about what happens to the current regardless of drive, but that the default drive will remain voltage drive, not current drive.

This is a good time because there are serious people coming at this and yes, there are people who are doing measurements. Hans van Maanen uses current EQ so that the amplifier produces a voltage square wave, it also produces a current square wave. He claims that temporal (timing) effects are audible and suppressed when using current EQ that has not effect on the voltage of the amplifier (because that is the nature of a voltage source). What he calls temporal I call time smear - and yes, it is measurable.

I have included a measurement below, where the amplifier produces square waves on both the voltage side (Yellow) and current side (Purple) into a speaker where the current EQ makes sure that the current drawn is the same (or very close) at all frequencies. Listening panels have heard the sound improvement, but of course things are never that simple. One day we shall even have an ABX regimen and I have no problem with that. If done correctly I believe it to be audible even if I am not the fan of ABX I used to be.

Please see attachment 2KHz Voltage and Current.

Cheers, Joe

scott wurcer said:
I also have a weakness for Quigley Down Under...
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AKA, Magnum goes Down Under. 😀
 

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Joe Rasmussen said:
AKA, Magnum goes Down Under. 😀
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I guess we're in for another round of your trolling, I wish you would go to the vendors forum with this stuff because you do have something to sell.

Wake me when it's over.

Joe what is the attraction to keep coming here and posting your theories?
 
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scott wurcer said:
Joe what is the attraction to keep coming here and posting your theories?
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The way he explained it to me (I had not asked) was that there was a secret conspiracy on DIY Audio, of people who opposed him and his thinking. They kept shouting him down and censoring him when he tried to present his ideas. and his threads got shut down. However, "the Blowtorch thread" was a special place where moderators allowed more leeway, so he hoped to "stealth" his ideas in this thread until he could get enough momentum to present them more radically without anyone questioning him.

At that point I asked him to stop messaging me.
 
scott wurcer said:
I don't quite understand, Joe has his Elsinore thread where he and his posse can ruminate to their hearts content. There is no conspiracy he is just wrong and promoting a personal BS view of things.
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I know all those things, just reporting what he told me in unsolicited private messages, which I think go some way to answering your earlier question.

I no longer have any interest in interacting with Joe.
 
nezbleu said:
The way he explained it to me (I had not asked) was that there was a secret conspiracy on DIY Audio...
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Oh, no.

We have almost coconut-headphone thinking that bullying people who misuse technical language in the slightest way will bring back the old days with lots of experts in forums who left because of garbage like bullying.

We have conspiracy thinking about people sneakily trying to sell things without revealing their true purpose, now this.

It would seem not very flattering in what it suggests about people attracted to forums, on average. Wouldn't be surprised if the more sane people with strong offline social nets get driven away disproportionately.

There is of course another group who just want to collaborate with normal, well-adjusted people who are interested in audio. And, of course everyone sees themselves as being exclusively a member of that group.

What a mess.
 
Well, whatever it is, it's been going for 25k posts + the previous threads that got too large. Like a slow moving train-wreck that people can't look away from 🙂.
 
john curl said:
What a mess, indeed!
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Sure is. Progressive thinking versus extreme conservatism, but this has a long history but it does seem to have been ramped up lately. Note the personal stuff? I won't respond to it. I thought there was rules?

The odd thing is that I am nothing like what they think of me. My thinking is actually fairly conservative (ask Dan who has called me a number of times, he is far more out there). You wouldn't know... oh well.
 
What started the "steady state mess" by triggering the "FUD shouting" was this post :

Jakob2 said:
It is still useful to remember that measurement with sine-waves (you know single-tone or pure-tone 🙂 ) in the usual way (means using a distortion analyzer or voltmeter) is considered as so-called "steady state" measurement.
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which, I think, covers in short what the relevant literature says:

Of course, we find the steady-state response of a
physical system by applying the excitation, allowing the system to settle into steady state, and then measuring the response.
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(Phillips, Parr,Riskin; Signals, Systems and Transforms, 4th Edition, Pearson Prentice Hall, 2008, 517)

Messrs. Schoukens, Pintelon, Oudeeraa and Pinneboog mentioned the method too in their paper from 1988:

A. Periodic Signals
which is changed from measurement to measurement.
1) (Stepped) Sine: A pure sine wave the frequency of
x ( t ) = A sin 2 pi ft
.
.
C.(Stepped) Sine
Crest factor square root 2,TF = 1,no leakage
1) Remarks: The time factor should be used carefully
because it does not take into acoount the time to get the
stead-state response after a frequency change.
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(J. Schoukens, Rik Pintelon, Edwin van der Ouderaa and Jean Renneboog; Survey of Excitation Signals for FFT Based Signal Analyzers, IEEE Transactions on Instrumentation and Measurement, Vol 31, No 3.
September 1988)


And if someone wonders why the quite innocuous statement in my post could have evoked this "mess" , he is not alone..... 🙂

syn08 said:
All clear, your distortion of reality is intended only to stir the pot, since nobody sane can misunderstand my quotes. I no longer fall for this BS, go ahead, you have the last word.
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q.e.d.
 
PMA said:
To which of the groups you consider to belong? Based on your thoughts on "first cycle distortion", resistive speaker impedance to reduce distortion or class AB inability to drive complex load I would guess the extreme conservatism group, or extreme superstition group.
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Sorry, can't make any sense of that. Could you rephrase it, please?

I do know that I am not superstitious, know some who are though.
 
tapestryofsound said:
Think I will be moseying on over to the speaker forums and hang out with the practical people and make some sawdust.
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I hope you aren't disappointed by all the technical/theory stuff that's bandied about 🙂

Markw4 said:
Sure, I have mixed feelings, and I am imperfect. But, I try to behave myself, and hopefully succeed most of the time.
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No, don't flatter yourself 😉, you have your own unique way of misbehaving
 
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