11 Jun
2010
11 Jun
'10
3:21 a.m.
I think this would be an excellent area to investigate
with your
tools. Almost a better use of the scientific method than whole
soundcard testing because you can focus on a single variable that is
known to be problematic.
...*reputed* to be problematic. The issues people have with
capacitors tend to be the big, low-ESR power caps that are driven hard
their entire lives. The conditions for audio caps are very different.
And unfortunately, electrolytic capacitors are the one
component that
are about as far from their theoretical ideal of any component.
No, not even close. Cored inductors are *way* worse. Transistors
themselves are far less linear then caps.
In
fact, i think it's totally braindamaged to be using electrolytic
capacitor for audio coupling...
Also false, and I've proven it to myself experimentally.
Electrolytics used to couple small signals (such as line in/line out)
affect audio unmeasurably, unless the cap is dead or the circuit is
incorrectly designed.
Caps can make a difference in filter circuits where they're operating
near the active area of the filter, but I've never been able to
measure any electrolytic contribution to an audio circuit in a strict
coupling function.
At one point I had intended to write up the differences between
various capacitors used in output stage couplig via direct
experimental measurement, and found that I couldn't actually measure a
damned thing. No measurable contribution whatsoever (down to -110dB,
my measurement limit). None. Zero. Nada. The analyzers that were
far more sensitive than my very good ears couldn't tell the caps from
a wire.
Monty