John Curl's Blowtorch preamplifier

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For input stage + VAS folded cascode + ideal buffer + FB, the distortion is very low (much les than 0.001%), at some 55Vpeak:
 

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Right you are PMA, it won't work as printed. I will have to get you to 'proof' my schematics in future. I should have seen this. Fortunately, it does not extend to the layout, or else we would not have a working product. The PIN #'s are right however, that is why it still works. I will contact Carl and have him update the schematic. By the way, we now use rev N and will probably change that soon, so some details are missing.
 
superconductivity

john curl said:
Auplater, do you know why superconductivity would bypass the 'residual resistance' of normal wire?


dunno about "normal wire"... probably has to do with the BCS model... you're the physicist...

I'd suppose since the electron/phonon cooper interaction responsible for superconduction would presuppose lack of impurities, vacancies, and lattice defects (pinning dislocations, etc.), as the wire probably wouldn't superconduct if these existed and/or caused a problem, perhaps given a different mode of conduction, these presumed "residual effects" wouldn't be an issue in a correctly made superconducting interconnect.

But again, I'm just a lowly materials guy, not a physicist.😉 😉

John L.
 
john curl said:
You are probably right, as well, Wavebourn. I should have added a 100 ohm resistor.

This I don't understand. It either worked without it or not. Why would you need to add it after the fact? To be safe, to be politically correct? Just in case..............

I think this just took a turn into the stupid zone and I really thought there was an undercurrent of sanity that was open to the possibility that there might be other outlooks.

What I was alluding to was: if one design works without them and one is unstable unless they are there, what would a curious person do?

This is what I do. Interesting results sometimes.

Whatever, enough.
 
myhrrhleine said:

Sure.
But there are audible sounds which ou can hear, but may not realise it.
Some 'study' may have told you it is not audible, and you believed it.
It's like hearing below 0.1Hz
Most will say it can't be done. Yet many do hear that low.
They even make earplugs to reduce the loudness.

For these signals you might say, "I don't hear them but they give me a funny feeling."
 
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