John Curl's Blowtorch preamplifier part III

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George, pp. 314-325
 

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I remember trying to characterize a digital meter in 1989 that had a 16 bit dual slope converter preceded by a 3 bit PGA. The idea with the instrument was that we could pick off small thermocouple spans riding on large process offset temperatures - so a furnace operating at 525C and customers wanted to say read from 500 to 550 so they were able to just program the range in.

One hell of a thing to be able to get repeatable measurements during development - ice flasks for CJC, fiddling around with thermal gradients on the meter leads (an 8.5 digit HP meter - can't recall the model number).

Reverse the cable and you'd have readings all over the place until the whole thing stabilized again.

Oh the joy of card board boxes to shield test bench set-ups from air currents.

:D
 
You treat thermal drift as AC?

No, noise is AC???? Do you understand my point? BTW as jn pointed out metals (even pure metals) all exhibit the Seebeck effect which can profoundly contaminate nanovolt/pico-amp measurements.

I have used this twice to debug micro-volt level circuit problems one fixable one just had to remain. It turns out gold bond wires to kovar lead frames have a very small thermocouple potential but enough to cause 5uV offset in an instrumentation amplifier due only to the temperature difference between the input pins after warm up.
 
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there is a difference between jfets and bipolars, but I invented both complementary differential input stages, separated by a 4-5 year interval. So, in 1968, I used bipolars for my amp input stage, and later I used complementary jfets for the GD, and ultimately for the Levinson JC-2 line stage. See schematic.


I remember being very excited seeing that layout for the first time when it appeared in Audio Amateur (many moons ago). Did you design the M Levinson LNP-2 also? Their literature seems to imply it, but? I recently saw one sitting unused and forgotten in a closet - yikes.


Much thanks, as always,
Chris
 
No, noise is AC???? Do you understand my point? BTW as jn pointed out metals (even pure metals) all exhibit the Seebeck effect which can profoundly contaminate nanovolt/pico-amp measurements.

I have used this twice to debug micro-volt level circuit problems one fixable one just had to remain. It turns out gold bond wires to kovar lead frames have a very small thermocouple potential but enough to cause 5uV offset in an instrumentation amplifier due only to the temperature difference between the input pins after warm up.

As usual....

This relates to my tests which use a narrownand AC filter to look at the expected test result?
 
Back on track, are we evenharmonics? It doesn't matter much what Max or anyone else uses, you will not be able to match what Max does to them, because it is confidential what he does. Apparently he would like to develop a service from improving electronics. Very commendable in my opinion. My colleague, Jack Bybee does much the same thing. It has been very useful to me for the last 25 years.
JC, thanks for the encouragements.

Evenharmonics, yes, I am about improving audio/video electronics of all kinds, and counter to JB's BQP method, my method is instantly fittable (no shut downs, no wiring modifications), no exotic materials or processes, easily mass producible and economical therefore available to all as OEM or retrofit, and for good reasons.
Like I have said recently and in the past, my method has been trialed on innumerable examples of portable, domestic, hi-end and pro audio and with the same subjective results which is a new clean, clear, friendly, fun, happy sounding audio......so many systems regardless of cost fail this primary test but can be improved or 'cured' in an instant.

What is this clean, clear, happy sound ?.....it's amplified or reproduced sound that just sounds 'right' immediately and long term and that's not just my opinion.
We have all heard systems or items that sound good, darn good, impressively good, but after extended listening and living with them find them to be still not quite 'there'......yet !.
So we keep chasing, keep reading reviews, keep experimenting, keep buying new gear, keep buying new 'accessories' like power conditioners or cables or stands etc, this keeps on until some kind of balance point like perceived value, finances, WAF etc settles.
But, that yearning is still there for the 'audiophile', no different to the wine connoisseur, the collector, the junkie.

So what if typical economical home systems just sounded 'right' from the get go ?....that means for us 99%ers.
What if headphones all just sounded 'right'......etc etc.
I believe I have that solution and my mission now is to document and explain the operation of this 'concept'.
Along the way I have encountered factors like wire directionality that I have proven to my satisfaction to be perfectly real.
Counter intuitively perhaps, it is because of my filtering method that subtle effects like directionality become starkly apparent, and when viewed from energy transfer point of view seems inevitable for the likes of drawn wire.

Like my signature says, "Never ignore the noise, it carries information".....in other words system 'noise' is information and we pick it up even down at -80dB, and this system 'noise' can be changed in spectral and dynamic behaviours which has downstream multiplicative/interactive consequences.
To this end I can render system noise more white and it subjectively disappears, and I can then 'flavour' the system noise and system sound character/signature" at will.
EH, that's part of what's going on I hope this helps.


Dan.
 
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Fascinating discussion, too bad Esslin, Ionesco, Jarry, Beckett are no longer able to take notes.


Spoiler alert: Godot couldn't make it. OTOH, this doesn't seem so terrible, as long as it's adjustable down to zero, no harm, no foul. It's accumulated a lot of baggage and bad press for reason, but in the context of one person exploring personal preferences, it's not fatal.


Might even be fun to try. Remember when some folks experimented with deliberately adding tape noise or phono surface noise? Maybe a simple colored dither (adjustable!) might be informative. Dunno. Worse things have happened.


All good fortune,
Chris
 
JC isn’t replying to PM. I was trying to ask what he needed hookup wire for, well I have one suggestion. (Ok maybe more than one but I don’t know intended use)

ZenWave Audio sells their own proprietary gold/silver mix made by Neotech. It is a different ratio than you can by from anyone else, and it is Litz. Dave, the owner does practice good engineering. He may sell some exotic-ish ends, but he doesn’t do any goofy stuff.
 
Spoiler alert: Godot couldn't make it. OTOH, this doesn't seem so terrible, as long as it's adjustable down to zero, no harm, no foul. It's accumulated a lot of baggage and bad press for reason, but in the context of one person exploring personal preferences, it's not fatal.

I was thinking more in terms of a chorus in absurd theatre.

Same as in the Greek theatre, chorus would form a collective character who expresses opinions and occasionally threatens to intervene. It also expresses authors point of view and generates standards by which actions of individual characters could be judged. Also serves as the ideal spectator, reacting to events, adding color. movement and spectacle.

No opinion or preference is fatal, but some times the chorus seem to sing and dance for La Cantatrice Chauve.
 
... I believe I have that solution and my mission now is to document and explain the operation of this 'concept'...
God speed Dan, you do that. You have stated much as you can while trying to be as non offensive as possible. A "Happy sound" is not a good term to use, it could also mean the treated system becomes incapacitated to convey other emotional content through sound. Perhaps it is best to focus more on measurement for now.
 
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George, pp. 314-325
Thank you Mr. Curl.
For the time, I don’t have access to it but I will soon.
I am interested to verify how much externally applied energy is referenced there for to generate crystal defects and movement of grain boundaries. Chances are the electric fields will be orders of magnitude higher than those generated by the potentials in use in audio or home main’s electrical installations.

in the Greek theatre, chorus would form a collective character who expresses opinions and occasionally threatens to intervene. It also expresses authors point of view and generates standards by which actions of individual characters could be judged.
Also serves as the ideal spectator, reacting to events, .

Yes. Chorus was meant to represent the citizens of the city/state (performance was actually a socially instructive act. Drama was “taught” to the public, not “performed” in front of a public)

adding color. movement and spectacle.

Only in comedy, for to satire the “excess” in someone’s behavior.
In drama it was not even considered to be utilized. Movement was minimal, slow and collective. Masks held in front of the faces had the intended gesture imprinted, also made the voice coming out louder and uniform (filtered).

That said, I have seen burlesque performances of classic drama, praised by the audience for the innovation introduced by the director …. “merdre”


No opinion or preference is fatal, but some times the chorus seem to sing and dance for La Cantatrice Chauve.
:up:

George
 
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So, you're adding dither? Seems a little after-the-fact, but certainly not fatal.

Not quite sure how it can be adding dither - as:

my method is instantly fittable (no shut downs, no wiring modifications)

From what MH has said, it's a goop that is applied to the outside of things, hence no need to even disconnect a cable...
 
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