The specific distortion profile matters. Summary measures are meaningless,
and at least one study shows _no_ correlation between something like THD
and human perception of distortion (see
http://www.gedlee.com/distortion_perception.htm for their AES paper and
study results).
Eeyore wrote in
:
Patrick Turner wrote:
The dielectric constant is an issue with caps.
With film caps ? Any plastic film cap ?
But not in coupling caps in tube amps where the
charge across a cap remains virtually unchanged
while the amp is running.
If the distortion in the cap is 0.01% which is all you'd ever expect
to measure
In a *film cap*. You have to be barking mad !
I've only ever measured that kind of distortion with zero bias
electrolytics under worst case conditions ! Film caps have distortion
that is umeasurably small. Certainly less than an AP test set can
measure and that means 0.0007%
Indeed measure an AP back to back and you get ~ 0.0006-0.0007% and
there's several film caps in the circuit already.
If you're going to make comments of that nature you'll need to be able
to back them up.
Graham