[sci.electronics] Generalizations

keithe@tekgvs.TEK.COM (Keith Ericson) (08/12/87)

In a couple of earlier articles some other folks write:

>>Really want to make it sound MUCH better? Pull all the electrolytics out of
>>the preamp and power amp and put in 2 uF mylars or polyprops if you can
>>find them.
>
>Bullsh*t.  Most of the capacitors in the preamp and power amp are on
>the order of 50 to 100 uF; the smallest are 4.7uF.  Replacing them with
>2uF polypropylene caps is going to change the sound, that's sure
>enough.

Folks - this is just a microcasm of what we see on the net, and in
audio-hype publications _ALL_THE_STEENKENG_TIME_!!! There is always
the feeling that "if it worked here, in this circuit, for me, in my
application, it must be a GOOD_THING and YOU should do it, to." To
borrow the response above, "Bullsh*t."

There is a reason for umpteen different kinds of capacitors, scads
of different phono cartridges, and "billyuns and billyuns" of every
other kind of parts and pieces: some perform better IN THEIR
PARTICULAR AREA OF SPECIALIZATION than do others.

Generalizations are, in general, not worth a hoot (except for this
one, of course :-) ). If things in life were that easy we wouldn't
need engineers (or doctors, or... or...) because we could all just
"look it up in the book" and solve our problems. It just ain't that
simple!!! And you can't MAKE it that simple.

Just remember the old trick in taking multiple-choice/true-false
tests: any statement that contains "always" or "never" is most
likely false. Apply that credo to life and you'll filter out a lot
of worthless crap. And perhaps prevent yourself from disseminating a
lot of worthless crap.

Thanks for listening (?).

keith 

bblue@crash.CTS.COM (Bill Blue) (08/14/87)

In article <2551@tekgvs.TEK.COM> keithe@tekgvs.UUCP (Keith Ericson) writes:
>In a couple of earlier articles some other folks write:
>
>>>Really want to make it sound MUCH better? Pull all the electrolytics out of
>>>the preamp and power amp and put in 2 uF mylars or polyprops if you can
>>>find them.
>>
>>Bullsh*t.  Most of the capacitors in the preamp and power amp are on
>>the order of 50 to 100 uF; the smallest are 4.7uF.  Replacing them with
>>2uF polypropylene caps is going to change the sound, that's sure
>>enough.
>
>Folks - this is just a microcasm of what we see on the net, and in
>audio-hype publications _ALL_THE_STEENKENG_TIME_!!! There is always
>the feeling that "if it worked here, in this circuit, for me, in my
>application, it must be a GOOD_THING and YOU should do it, to." To
>borrow the response above, "Bullsh*t."
>
>There is a reason for umpteen different kinds of capacitors, scads
>of different phono cartridges, and "billyuns and billyuns" of every
>other kind of parts and pieces: some perform better IN THEIR
>PARTICULAR AREA OF SPECIALIZATION than do others.

Sorry Keith, but you can't just generalize this away by observing
(and reacting to) the fact that various components sound differently in
audio circuits.  And it has nothing at all with which one was
recommended. It has been widely known and accepted for *years* that,
specifically, mylar and polypropylene capacitors are outstanding
performers in an audio path.  It doesn't matter which audio path, or
anything else.  It is an absolute.  It's as absolute as the knowledge
that metal film resistors a) also sound better than carbon comps, and
b) are lower noise.  The biggest problem with using those types of
capacitors is that they are large for a given capacity.  You could, for
example, find a 4700mf electrolytic that is quite smaller than a 5mf
polypropylene.  That, and their expense (and to a lesser degree
ignorance of some designers) are the major factors in why we don't see
them in anything but the higher quality audiophile equipment.

>
>Generalizations are, in general, not worth a hoot (except for this
>one, of course :-) ). If things in life were that easy we wouldn't
>need engineers (or doctors, or... or...) because we could all just
>"look it up in the book" and solve our problems. It just ain't that
>simple!!! And you can't MAKE it that simple.

Yes, there can be a lot of generalizations...  a) cars designed for use
with unleaded gas should be fed unleaded gas, b) A component that is
designed for use with AC Current cannot be fed DC current and be
expected to still work, and c) polypropylene caps will sound better than
electrolytics in *any* audio path, given an appropriate value selection.


Part of the problem here (and possibly with other absolute statements)
is with people's reaction to the word 'better'.  To avoid this confusion
and put things in perspective, I will clarify my original statement:
Polypropylene and mylar capacitors will introduce less signal distortion
into the audio path than will electrolytics.  How this is perceived
(i.e. is it better or not) will depend largely on what you want to (or
expect to) hear.

--Bill