bountyhunter
Well-Known Member
On his website, **broken link removed**
Rod Elliot measured 3% distortion across a ceramic capacitor that was attenuating its own distortion so its distortion was worse.
I'll study it more thoroughly when I get a chance, but this is likely where the disconnect is:
What is often missed completely, is that capacitors used for signal coupling must have a very low impedance for all frequencies that one expects to pass through the system
That is simply flat wrong for the design I used with FET input amps which have very high impedance. The capacitor's varying impedance doesn't matter if it is varying from "very negligible" to "extremely negligible" compared to the impedance it is driving into. In some designs, the coupling may be critical if the input impedance is low. Mine is very high. I learned that from an old designer (always use a good high impedance buffer stage first).
EDIT: perused the article, and I do have to give him points for honesty: from the article:
Perform all the blind tests you can with capacitors used in real circuits. Having done this, if you still think there is a difference (and can demonstrate it to others in a blind test), then you will probably be the first to do so.
And:
These effects are examined by a combination of simulation and actual testing. Simulation features heavily here, simply because most of the effects are extremely difficult (some are almost impossible) to measure. The resolution of the simulator is far greater than any known test instrument, but one has to be careful to ensure the models used act in the same way as real components.
Yep, that's where the train always jumps the tracks.....
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