John Curl's Blowtorch preamplifier part III

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It can't do L-R to M-S conversion and I need twiddly knobs for adjusting. The pragmatic approach would be to do the conversion in analog and feed through a DEQ2496 , but that's extra conversion stages and the UI on the DEQ isn't great. I fear once again I am in a group of one in my requirements.


Yup, that is the cheapy version!

I've got an old Rane graphic if you want it
 
I'm not talking mechanical ' agitation ' ............
I mean the variance of the signal voltage
It manifests like a super class B 'ness .....

I understand but it can't there is no physics for that. Did you read the quote, a several micron gap is an open circuit to several hundred volts metals touching is ohmic? The minimum voltage in air to jump a gap at atmospheric pressure is 327V. The only variance would come from ohmic changes due to current density. At small signals there is not much possible going on and it would be symmetric not rectifying I would think in any case. I certainly am open to any evidence otherwise.

I could suggest some experiments like take two very fine wires contacting at 90 degrees passing a very small signal sin wave and them slowly break the connection and inspect the result as the connection is broken.
 
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There is some info I could not find in a quick scan of the net on low level signals and contacts. JC probably has hard copy somewhere. In any case on initial contact, some energy level is needed to initiate conduction. Once that has happened its a continuous metallic connection (no class B dead zone). The energy level needed is very low. I have meters with sub microvolt sensitivity at 100 MegOhm Z with input relays that work fine. I do not think it's an issue. The relay I linked to is a reed relay in a system with -140 dB internal harmonics. A distorting relay would really stand out in that application.
 
There is some info I could not find in a quick scan of the net on low level signals and contacts. JC probably has hard copy somewhere. In any case on initial contact, some energy level is needed to initiate conduction. Once that has happened its a continuous metallic connection (no class B dead zone). The energy level needed is very low. I have meters with sub microvolt sensitivity at 100 MegOhm Z with input relays that work fine. I do not think it's an issue. The relay I linked to is a reed relay in a system with -140 dB internal harmonics. A distorting relay would really stand out in that application.

Reed relays are sealed. The issue for unsealed relays is what the atmosphere does to the contacts. I haven't seen a glass sealed conventional relay. Plastic cased relays are subject to out-gassing. That is why bifurcated crossbar contacts are used. High mating force and four contact points. One of the four should mechanically punch through the contamination. A practical solution.

Reed relay distortion drops as current decreases, so high impedance circuitry would reduce distortion and mercury wetted contacts would allow low level operation. The right relay properly used.

My last physics prof friend was very succinct on the subject. The rules apply 80%+ of the time, but not always. (Who would have though there is a difference between theory and reality?) He also had a rig where the low level problem showed up.

His other interesting story was one of his major projects required no iron in the vicinity. They had to pull the rebar out of the concrete in his space, not a cheap project.
 
His other interesting story was one of his major projects required no iron in the vicinity. They had to pull the rebar out of the concrete in his space, not a cheap project.

That's why I had to build a wooden bench for my air core coils. Steel top benches were standard issue.

EDIT - Sorry I missed the point, we never used unsealed relays for anything and I have only used one as a turn on delay for power supplies.
 
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> I certainly am open to any evidence otherwise.

I'm surprised you've never had it happen ....

Not what you describe, abrupt rectification as in a singularity of derivative in V/I. Why not make a little picture of what you mean if that is not it. Cat's whiskers, etc. are semiconductor junctions and behave more or less like a diode.

Example copper to grossly corroded copper, no "dead zone" Home Made Diodes From Copper Oxide | Hackaday
 
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Democratization of science.

Well said, the electric universe also comes with the typical disdain for all theory and math.

The idea that outsiders ("the people") will revolutionize physics, in a way that those outsiders understand, is powerful. "Science is returned to the people—the garage tinkerer, the practical engineer, and the natural philosopher," Thornhill told Motherboard. "People say to me that it has changed their lives because it makes sense for them," he said. "And because it is a real cosmology, there is something for everyone, be they scholar, artist, engineer, or the 'man on the street.'"
 
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