John Curl's Blowtorch preamplifier part II

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But that residual would be the nonlinear component, at least if we are reasonably sure it is not the limitation of the modelling accuracy.

Jan

Fitting over a range of amplitudes could uncover a change in R's and C's with current/voltage which could be fit to a non-linear function for each component. BTW SPICE has no problem with polynomial descriptions for R and C.

https://www.cadence.com/rl/Resources/application_notes/nonlinear_capacitor_model_appnote.pdf
 
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Wasn't saying capacitors could be modeled accurately with only linear elements. Not disputing non-linearity in capacitors. I was referring only to the DA portion of the model.

se

OK, then the question would follow: if the non-linearity is not caused by the DA, what other 'parts' of the capacitor could then cause it? Except for the dielectricum, there's the electrodes, the wires, what else. What do we know about those in regard to nonlinearity?

Vacuphile brought up air condensors from vintage radio's. Do they show nonlinearity?

Jan
 
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OK, then the question would follow: if the non-linearity is not caused by the DA, what other 'parts' of the capacitor could then cause it? Except for the dielectricum, there's the electrodes, the wires, what else. What do we know about those in regard to nonlinearity?

Not a question that particularly interests me actually.

This whole thing began when Richard claimed it was DA that was responsible for the capacitor distortion he said he had measured. He stated this unequivocally, and just as unequivocally said that the DA models needed to be revisited to include this non-linearly.

He was asked just how he was able to isolate DA as being the culprit, given that DA was quite accurately modeled using linear elements. And that is what led to this train wreck.

My point has simply been that DA isn't this hugely frightening audiophile Bogey Man that it's been made into by Richard, John and others over the years.

se
 
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...was asked just how he was able to isolate DA as being the culprit, given that DA was quite accurately modeled using linear elements.
se

Well sure, but given that we DO have cap distortion, I'm surprised you're not curious to know where it comes from. That might help us to select the right cap for a specific purpose.

But hey, it's not my beef either.

Jan
 
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