John Curl's Blowtorch preamplifier part II

[scott wurcer]

Mercury is the cure 😉. Mercury filled hoses.

Ken will sell you a safe equivalent. 🙂

 

[gk7]

At least John has proved that he knows how to scan pages out of second year physics texts. The point is unclear, maybe even non-existent, but not everyone his age knows how to work a scanner, so mad props for that accomplishment!

Where I do come from such a tasteless comment would be regarded as very bad manners.
Moderators are "more equal" obviously...

 

[john curl]

Oh, but it HAS, Kindhornman. That is the nature of the controversy.

 

[jneutron]

Hi John,

Actually, what I tried to describe was the Lenz effect, differenting flux modulation along two vectors; aligned with, and perpendicular to the pole piece. Couple of thoughts:

1. a copper shortening ring fights flux modulation in the pole piece by generating back EMF. The main disadvantage as I see it is that it lowers driver sensitivity. You need to put more energy in without having more work being done.

2. a slit pole piece does nothing to prevent longitudinal flux modulation in the pole piece, and this is the distortion mechanism a shortening ring attempts to minimize.

3. resistance is determined by material, diameter and length of the VC wire. It is as such not influenced by stuff send back into the voice coil. Everything sent back into the VC might show up as you call it an increase in effective resistance, but the stuff sent back into the VC will be at a phase angle, so we should really speak about impedance here.

4. aluminum braking, iron eddies, shorting ring eddies therefore will not show up in electrical measurements as an increase in R. They will rather show up as a decrease in Qms, a decrease in impedance, or both. I can't immediately envisage a mechanisme could result in an increase in impedance, for example because of the braking effect of a conductive VC.

5. the real problem I see with a shortening ring is that a voice coil around a solid core (pole piece) with a shortening ring constitutes a lousy transformer, exactly because of eddy currents in the core. The non-linearities these eddy currents introduce will translate into distortion products. Your slit core would make it a better transformer, so I surmise it could be effective in lowering distortion. But you will still need a shortening ring, see 1. and 2.

All eddy dissipation results in increased Rs. Any braking dissipates as well, resulting in increase in Rs. All Lenz effect decreases inductance by definition, and the currents within the material which creates the opposing magfield will dissipate within the solid.

There are so many ways to look at this problem, no? One can get lost in trying to compare 1 to 1 what we speak of..

If we can eliminate eddies and make the reluctance circuit stiffer, I bet we'll get better sensitivity and less distortion. Q is always, what cost..

jn

 

[SY]

Where I do come from such a tasteless comment would be regarded as very bad manners.

As Epictetus would say, "And when did I tell you that I was polite?"

If I recall correctly, you're from Austria? I do have many stories about my time there.

 

[SY]

Oh, but it HAS, Kindhornman. That is the nature of the controversy.

There's no controversy. An unpublished and unsupported extraordinary claim from a quack is not going to convince anyone, unless they are either terminally stupid or trying to sell something. "Controversy" implies that there's actually something to argue about.

 

[Groove T]

Mercury is the cure 😉. Mercury filled hoses.

Only when embedded in heavy water and shielded with LED-light feed with batteries!😛

 

[john curl]

That's me, "terminally stupid" '-)

 

[scott wurcer]

If I recall correctly, you're from Austria?

Watch it there, we could all settle this over a big platter of Zwetschkenknoedel (even you can eat those). 😀

I do miss our neighbors tree, these are not a big commercial crop here.

 

[SY]

We just had something like that, but with a Polish name that I can't pronounce. Apparently a very big deal here at this season.

 

[SY]

That's me, "terminally stupid" '-)

My assumption is that you're smart enough to know that this bizarre claim is nonsense.

 

[john curl]

No, I don't. About 30 years ago VDH contacted me in a hallway of an AES or CES and told me about his 'measurement', the test equipment that he had to buy to do it, and what it meant.
I don't sell cable, so why did he tell me?

 

[SY]

I don't sell cable, so why did he tell me?

It's all about keeping the true believers believing. And in VdH's case, preying on the sick and desperate.

 

[john curl]

Everybody else, what have you learned from reading these last few pages?
1. The physics of electrical conductivity is more complex than you thought?
2. Quantum mechanics is 'crazy' and it is almost impossible to make a consistent model from it?
3. Maybe, just maybe, electrical conductivity is not as 'robust' as early models suggest? Please comment.

 

[john curl]

First Bybee, now VDH, who's next? '-)

 

[SY]

Is Bybee selling quack medicine? I had no idea.

 

[john curl]

You should see the new stuff we are trying out. Magic! '-) However, we are BUYING, not selling the latest stuff. Some people are crazier than us! '-)

 

[scott wurcer]

We just had something like that, but with a Polish name that I can't pronounce. Apparently a very big deal here at this season.

Knedle ze śliwkami, I don't know how to pronounce it either.

 

[scott wurcer]

You should see the new stuff we are trying out. Magic! '-) However, we are BUYING, not selling the latest stuff. Some people are crazier than us! '-)

If they're selling, I would think they aren't that crazy after all.

 

[Kindhornman]

I would think if there was any new physics or important new discoveries about basic electronics that we all need to learn both JN and Scott would inform us about that. Scott works at a level of scale that none of the rest of us have to think about and JN works with some of what we are calling weird quantum science and super conductivity. I believe when they tell us that these unusual claims are to be ignored that we should listen.

John,
You have developed some very well received electronics circuits in your time in this industry and though you may be somewhat stuck in the use of older devices I do believe that you can design a circuit with many of the newer opamps if you wanted to do that. It just doesn't sell into the market that your products are aimed at and I understand that an accept that. There is nothing wrong with being successful in a niche market, that is a goal that many would be happy to achieve.