"b" wrote in message
ups.com...

Eric ha escrito:

Hi,



I have a question about the audiophile capacitor replacement. In normal
production boards, signal coupling capacitor normally using polar
electrolytic capacitors. In some higher grade models, bi-polar
electrolytic
capacitors will be introduced. Some people will upgrade it will audio
grade
capacitors such as oil caps, polypropylene caps. In my audio device, the
coupling caps are 100uF polar electrolytic caps. I am looking for Jensen
oil caps and it will be very expensive and the size is very big. Someone
suggests me I can replace with 20uF oil caps instead of huge big one.

This all seems rather unscientific to me, with more than a whiff of
snake oil (dunno about capacitor oil!)
- since when can you reduce the capacitance to a fifth of the value of
the original and expect good perfomance?
What utter crap. You'd end up with a result as if the amp had aged 20
years and the caps had lost their capacitance. Use always the same
value as the original: 100uF, with same or slightly greater voltage
rating.

Unless there is a fault with the appliance, (often evidenced by hum,
motor boating or excessive hiss on the output) I'd say don't mess about
changing caps for the sake of it. You won't hear any perceptible
difference. There are people out there making a living by spreading
this nonsense about to the non-technical.

-B.

Jensen copper foil / oiled paper caps as upgrade replacements, are usually
more associated with the lower values that you tend to find as coupling caps
in valve amplifiers. They are physically bigger than the bog standard
polyesters that you would normally find fitted, and are very expensive.
There is, however, a measurable improvement to be had by fitting them, but I
would have to question if the cost was warranted.

Their electrolytic caps are, IIRC, all high voltage types for valve amp
power supplies, so not appropriate for interstage coupling on semiconductor
amps. As they are high voltage caps, their physical size will be
correspondingly larger, so the only way to get the size back down, would be
to reduce the value. I agree with the other poster, that this would be a bad
move for the performance of the amp, and far from giving a performance
improvement, would likely result in a detrimental effect.

There may be a measurable difference to be had, by replacing conventional
interstage coupling electros with bipolar types, which are readily
available, and no bigger than conventional types, but I doubt that you would
be able to notice the difference in a real-world music playing situation.
Again, I would agree with the other poster that if it ain't broke, don't try
to fix it.If you want to know more about the subject, you could try the
people over on uk.rec.audio. I know for sure that there are a couple of
people there who have fitted Jensen caps to amps, and may be better able to
advise you.

Arfa