"Nick Gorham" wrote in message

Don Pearce wrote:
On Wed, 24 May 2006 13:10:40 +0100, Nick Gorham
wrote:


Jim Lesurf wrote:

In article , Nick
Gorham wrote:


Serge Auckland wrote:


I'll accept that pots, capacitors, resistors etc.
sound different when I see objective measurements
that indicate that there should be a difference and
the results of properly conducted double-blind tests
that show that there was a difference.



http://members.aol.com/sbench102/caps.html


I've only had a quick look at the above, and the pages
linked to it. However they don't seem to me to be
particularly relevant to the question of capacitors
normally having a 'sound' in normal use. The first thing that struck me
about the page was the
following which I quote:

"The signal level was held constant at about 70 volts
RMS at 600 Hz across the capacitors. (for about 26mA
signal current). This is probably more than you would
normally expect,..." My reaction to the last phrase was,,, "indeed!"
:-)

I can't recall ever building or using an audio
amplifier or tuner that had anything like this large
an *audio voltage* across any of the *capacitors*.
Note the above is 70v RMS *between the capacitor
terminals*. i.e. not just an input where most of the
voltage appears elsewhere. I have certainly built (and
use!) amps which have audio voltages this large inside
them, but not between the terminals of any of the
signal capacitors.

The fact you may not have built such a thing, doesn't
mean they do not exist. Using a coupling cap between a
driver and the grid of a 211 would have this sort of
voltage, as will most driver valves. a 845 would have a
much higher voltage.

A stupid problem associated with doing a stupid thing.

A even more extreme example could be a cap used in a
parallel feed output stage, that could have 1kv or more
across it.


You appear to be confusing DC conditions with signal
voltage. d


Maybe, ok, in both cases there will be a DC voltage, but
there will also be the signal voltage of the magnitude we
are talking about.

But, it won't appear across the capacitor's dielectric.