Most 'Musical' pF Value Cap

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Joined 2022
I've been going a little nuts as I'm sure quite a few on here could appreciate swapping caps in the signal path of my preamp. I've had great differences with LCR Polystyrene, Amtrans PP, CDM Mica, and the ceramics which were in there. PP can be very detailed but bright, styrene smoothner but maybe not the most accurate and veiled somewhat. Interested in some of your favorites - 100pF is my value.
 
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Joined 2018
100pF in the signal path? Like in series? That's a suitable value for an RF coupling cap, not audio...

Perhaps its a shunt load cap?

Or are you looking at a compensation cap (needed for stability)?

What's the preamp circuit, and where is this cap within it? Otherwise its only vague speculation that can be offered...
 
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Joined 2009
PP can be very detailed but bright, styrene smoothner but maybe not the most accurate and veiled somewhat.
Some people claim to detect dielectric used by ear, in exact same value caps.

Until I see proof of that {using double blind testing) I remain skeptical.
Correct that to very skeptical.
 
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Joined 2019
Id assume 100p is for stability.
So you cant hear it regardless.
In my old tube amps
ceramics could be microphonic.
But that took a good 40 years to happen.
 
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Joined 2009
Define "better sounding"
Beyond 120% subjective description, expectation bias, "listening with your eyes", etc.

In any case, something which sounds different will measure different, that's for sure.
The opposite does not necessarily happen.

As in:

* A Piezo tweeter sounds shrill and nasty.
Measurement shows an 8-10dB peak at 3 kHz.
Good.
Measurement matches that gross problem observation.

while
P
* Amplifier 1 measures 0.1% distortion; Amplifier 2 measures 0.01 % distortion.
Difference is easy to measure.
Easy to detect by ear?
Not that easy ... to put it mildly.
Yet a group of people claims they can.

Oh well.
 
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Joined 2011
Once again: any capacitor is not a simple capacitor. It is mix of a capacitor with series inductance and resistance of tails and plates, and shunt leak resistance of dielectric and packaging, that configures a complete filter. So it is obvious that changing the kind of capacitor maintaining the absolute value, will change amplifier's frequency and phase behavior.

But as JMF said, I'm too extremely skeptic you can listen such a difference.
 
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Joined 2019
My choice would be Wima FKP2 film/foil and if i want silver mica then i would buy Charcroft.

No experience with NOS boxed silver mica's.

Soviet K71-7 stacked polystyrene could also be a choice.

S+M orange polystyrenes, stacked, are said to be the best but the the range of values possible to find is extremly limited, usually 3,3n ( or 33n, i forgot ).
 
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Joined 2010
The OP hasn't got back with the answers to post #2, but I'll guess this 100pF is for compensation/stability as mentioned in #2. I'll further suppose the circuit works fine with 102pF, but is prone to oscillate (at some high ultrasonic frequency, of course, resulting in increase in noise and a definite change in sound) with 99pF. Thus capacitors with "different dielectrics" will sound different depending on their exact capacitance value, not their dielectric.
 
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Joined 2018
Once again: any capacitor is not a simple capacitor. It is mix of a capacitor with series inductance and resistance of tails and plates, and shunt leak resistance of dielectric and packaging, that configures a complete filter. So it is obvious that changing the kind of capacitor maintaining the absolute value, will change amplifier's frequency and phase behavior.
Are you claiming some capacitors in audio have a self-resonant frequency down at 100kHz or lower? Because that's what you need to start affecting phase and frequency response in the audio spectrum.
 
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Joined 2011
Several years ago with a friend measured a 1uF 50V lytic and found resonance at about 70KHz. This was in an new unit unused. And bigger C's will have proportionately lower resonant freq.
 
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Not to mention I know that I've seen pictures of long leads wound into coils for appearances I guess... A few extra uH always makes things interesting.
 
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