John Curl's Blowtorch preamplifier part III

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#28,243
Take a break and enjoy a snippet of the Swedish marine music corps marching for changing the royal castle guard in Stockholm. They are entering a larger field surrounded by 2-3 store buildings. My mics are setup in one corner of this field and the band is marching towards me on a narrow street just to make a left turn out on the field (going L -> R in the recording) and passing the mics at a distance of say 50 feet.

The attached sound file MarchIn.mp4 needs to be renamed to: MarchIn.flac in order to play.

Info L R
Minimum sample value -0.6115 -0.5152
Maximum sample value 0.6464 0.6445
Peak amplitude -3.8 dB -3.8 dB
DC offset -0.0000 -0.0000
Minimum RMS power -54.6 dB -53.3 dB
Average RMS power -25.3 dB -25.4 dB
Maximum RMS power -16.9 dB -17.4 dB
Clipped samples 0 0


2 x Line Audio OM1 (+ a Jeklin disk), Roland Quad-Capture, MacBook+Amadeus Pro.

//
 

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  • MarchIn.mp4
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#28,244
john curl said:
JN is going to get really nasty with Joe soon, just like he has done to me on occasion.
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Really? Provide evidence of such an accusation.

Now, is your statement a prediction or a request?

Regardless, I don't do requests.

john curl said:
However, I don't get much from him that is useful, and I think that is because he doesn't know either.
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It is more likely because you do not understand the concepts I speak of.

john curl said:
Now, what Joe is putting forth, is it useful? Maybe. I don't know, .
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Your a good man... to quote Dirty Harry.

You are welcome to participate in the technical discussion if you think you understand it enough and have something of merit to share.

If you think doing the Pom Pom thing is of merit, you are mistaken

jn
 
#28,247
Just ordered a Visaton BG20-8 from parts express. ETA 5 to 10 days.

At some point in time, disassembly was inevitable. It will be interesting to figure out how best to remove the moving parts without destroying them.

Also, to see what the gap clearance is between ID of front plate and OD of voice coil. That will determine the diameter of the co wound tap wire.

I also realized, I don't need to put two tap wires in if I just do a gain of two amp on the tap wind. I can tweak the gain in order to null out the emf component. And with a sweep, I can see how far up the spectrum the null will maintain. My thinking is the second vc layer is closer to the pole tip and I can't get the tap wire there.
Also, I don't need two speakers in order to compare response and distortion as the exercise is not to optimize the speaker per se, but to determine what the jn drive will do for the existing response and distortion characteristics. To that end, I can simply drive the existing coil with the tap coil simply sitting there doing nothing. That saves me about 40 bucks.

As I go through the process I will take many pictures and provide details. But probably not on this thread..

jn
 
#28,249
john curl said:
I add tweaks and mods as they come by, in order to improve the 'sound' of my hi fi. This is my latest:

discussion later.
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I thought the Bybee stuff was a bunch of hooey until I read this from Stereotimes, the same "publication" quoted by JC:

This is off topic, but during the review period, Jack Bybee recommended I install an iQSE in each front door panel and at the back of the trunk (inside) of my car. Allowing for overnight stabilization of the iQSEs, the handling, ride, smoothness of gear shifting, and throttle response on my heavily modified turbo charged 2011 Buick Regal T07 Russelsheim which is equipped with magnetic ride control and fuel injection was improved for the better.
​
Face it, anything that can improve a Buick Regal has got to be magic. I bet if he put the Bybees on each of the back doors too, it would have balanced the checkbook, cut the lawn, and grown hair on a billiard ball.
 
#28,251
PMA said:
Continuing in a driver distortion reduction scheme discussed about a half year ago?
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Yes. My expectation is that I will be able to do some very rudimentary checks on the rebuilt assembly, but I do not have the necessary precision gear to measure the distortion characteristics.

So I will keep the shipping materials in good condition to allow shipping to someone else for a more elaborate set of measurements of voltage vs current vs jn drive.

jn
 
#28,252
GOR3 said:
I thought the Bybee stuff was a bunch of hooey until I read this from Stereotimes, the same "publication" quoted by JC:

This is off topic, but during the review period, Jack Bybee recommended I install an iQSE in each front door panel and at the back of the trunk (inside) of my car. Allowing for overnight stabilization of the iQSEs, the handling, ride, smoothness of gear shifting, and throttle response on my heavily modified turbo charged 2011 Buick Regal T07 Russelsheim which is equipped with magnetic ride control and fuel injection was improved for the better.
​
Face it, anything that can improve a Buick Regal has got to be magic. I bet if he put the Bybees on each of the back doors too, it would have balanced the checkbook, cut the lawn, and grown hair on a billiard ball.
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Ha ha. I’m sure the guy that wrote that was just having a laugh. Seriously.

😀
 
#28,256
Personally, I would rather direct the conversation to how we can improve the electronics in our audio equipment. This also seems to be dismissed by the 'critics' here, so I am showing how far away my understanding of what works really is from JN et al. I think I might get Olsen's book out and review direct radiators. I am already trying to get the original 1925 Rice and Kellogg paper on direct radiators, but I am having a printing problem that may take time to fix. It seemed to me, when I first read it in 1975 (50 years after it was first presented) to be the most intuitive paper on how a loudspeaker really works in my experience. Maybe some of you should read a 'classic' text that gives you additional insight as well.

Complicit, me? I only comment on what I have tried. I have not tried these new Bybees yet. I don't know the best place to put them, yet.
 
#28,257
DF96 said:
If your claim was simply 'amplifiers work better with a resistive load' then it would be hard to argue against that, although some might say that any good amplifier can handle most reactive loads adequately well so the claim is true but only trivially so. Instead of a clear statement like that you tell all your stories about F=BIl and current drive and parallel loads being driven from a pure voltage source affecting each other, then cannot understand when we point out all the flaws in your reasoning. Finally you accuse us of not understanding and claim that a number of unnamed experts agree with you. This we take with a pinch of salt; either they are not experts or they do not understand what you have said to them or you have told them something different from what you have told us.
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Really amazing that a bunch of well educated and experienced EE's here do not seem to have a clue of what Joe R is after. Some psychological insight might help... It's attention guys, attention. Do you really think he is interested in a fruitful discussion on current vs voltage or whatever drive?? (Not @ DF but in general...) No, he isn't. He perfectly understands that he is not the EE knowing the basics like you, and he perfectly understands that he will never succeed in convincing you of what he says "he is after". Joe R is a clever salesman. With every reply here on one of his BS posts he gets the attention he is looking for because that is his only agenda; he is playing with you guys..... The only way of getting rid of him is obvious: ignore him, don't react. Sooner (hopefully) or later he will loose interest and will go elsewhere. Just my two cents.
 
#28,258
john curl said:
Personally, I would rather direct the conversation to how we can improve the electronics in our audio equipment. This also seems to be dismissed by the 'critics' here, so I am showing how far away my understanding of what works really is from JN et al.
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Awwww...and here I thought you didn't care...

john curl said:
I think I might get Olsen's book out and review direct radiators. I am already trying to get the original 1925 Rice and Kellogg paper on direct radiators, but I am having a printing problem that may take time to fix. It seemed to me, when I first read it in 1975 (50 years after it was first presented) to be the most intuitive paper on how a loudspeaker really works in my experience. Maybe some of you should read a 'classic' text that gives you additional insight as well.
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Sure, how about Abraham B Cohen's book..

Seriously, you should go modern, say, Klipple (granted he has some errors, I leave it to you to find them...a test as it were, fundamental flaw in thinking)

While your at it, look up ESA's stuff if you want some of the best.

john curl said:
I have not tried these new Bybees yet. I don't know the best place to put them, yet.
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OMG.....the responses that ran through my mind.... 😀

jn
 
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#28,260
daanve said:
Really amazing that a bunch of well educated and experienced EE's here do not seem to have a clue of what Joe R is after. Some psychological insight might help...
It's attention guys, attention..
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I wish I had your erudition in English, let alone Dutch, in which I could not order a ham sandwich.

I have not commented here before since I still try and follow my dear mum's advice to say nothing when one has nothing positive to say. But here comes the "but" - I do wish the rantings of narcissistic attention seeking trolls would just desist and start their own threads which i could cheerfully not join.
 
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