Eeyore wrote:

Nick Gorham wrote:

This might be of interest

No they don't. But only crappy ones.

High-K ceramics are fabulously non-linear. Med-K ones are only slightly
better. But no competent designer would use them in an audio path.

As for plastic film dielectrics, I doubt STRONGLY there's even any
remote hope of an audible difference.

However using the right VALUE and considering TOLERANCES is VERY
important and may mislead people into wandering up blind alleys.

Heck, even zero-bias electrolytics are audibly blameless when used
corrrectly. That's where an experienced designer's skill counts.

Graham

A client of mine had me replace all the Wima polypropylene MKP caps in
his tube amps
with Auricaps, and he reckoned his music sounded better, even though in
an AB test using
one channel with Auricaps and the other with Wimas, he couldn't pick
which one had which caps.
But when he had all the caps in both channels replaced, he still said it
made a difference for the better.

Then he had me replace all the small sized NP electros and polyester
bypasses in his speaker crossovers
with Obligato polyprops which meant the crossover boards had to become
much larger
to accomodate the much larger caps.
Even the caps in the impedance equalizing Zobels were changed to
Obligato.
The caps were of various sizes and types, and some looked like standard
polyprop motor starts,
and others were the same type of cap but encased in epoxy resin and
inside copper
and brass plumbing tubing, obviously aimed at impressing audiophiles.
So all the Obligatos were well sealed inside their containers, and had
little chance to
resonate physically.
The change to Obligatos made a difference to reduce the "edginess" of
the sound,
and made sound staging more defined, and made sound more "fluid", and
less tiring,
and more involving, and bass was especially better.
Great care was taken to adhere to the same values of C used as in the
original crossovers.

The client said the speakar upgrade expense was worth every cent of the
$600.

Methinks motor start polyprops in series with midrange drivers instead
of electros
need only be generic motor starts, not necessarily the Obligato brand,
and you should get good results.

Bean counters in up-market speaker companies hate such cap expense
because the cheapskate opposition
won't use them.

But expense on caps is a complete waste if the amps have high THD/IMD,
and the speakers have crap drivers
and poor boxes and were not made with a flat response, and the rest of
the system is crap.

Anyway, my client has the only system I know which I can listen to vinyl
or CD all night
without feeling "sounded out". It is streets ahead of everyone else's
systems I know.

Patrick Turner.