[Scott Dorsey]

In article , Trevor wrote:
On 16/02/2017 3:57 PM, PStamler wrote:
At the risk of attracting one of Mr. Allison's personal attacks,I
have measured the rise in capacitors' impedance at high frequencies
-- in some cases they switch from being capacitative to inductive
well within the audio band.

If you often use power supply filter caps etc. for audio coupling
purposes, that's definitely something you'd would want to take into
account I guess. :-) There is a reason why one selects components for
purpose of course.

Sadly, that was the technology of the 1970s. People were designing with
transistors but they were still thinking about tubes in their heads, so
everything was capacitively coupled and electrolytics were needed in order
to deal with the high values required due to the low impedances.

I was at a mastering facility a few years back with some audiophile label
guys who were looking at having some LPs cut. They asked the mastering
engineer if there were any electrolytic capacitors in the signal path of
the Neumann lathe amplifier and he about spit himself. "Millions of them!"
he said. "Millions!"

And so, because we live with a lot of older equipment designed in this
regime, we have to deal with it and we have to find capacitors appropriate
for the application.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."