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.
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...
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...
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.
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.
So you cant hear it regardless.
In my old tube amps
ceramics could be microphonic.
But that took a good 40 years to happen.
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.
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.
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.
But as JMF said, I'm too extremely skeptic you can listen such a difference.
My audiophile power cord sounds way better than your silver mica cal/100pf.
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 ).
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 ).
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.
Components don’t have “sound”. Circuits do.
Two different circuits, assembled from different components, can have exactly the same sound or transfer function. Remember the famous Carver challenge?
https://www.stereophile.com/content/carver-challenge
Two different circuits, assembled from different components, can have exactly the same sound or transfer function. Remember the famous Carver challenge?
https://www.stereophile.com/content/carver-challenge
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.
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.
Well, maybe he likes throwing a few multi farad supercapacitors in there because... more is better?
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.
https://techweb.rohm.com/know-how/nowisee/7549/
There is a more specific and better explanation than mine.
There is a more specific and better explanation than mine.
Most people over 25 can't hear the 2nd harmonic over 7khz. The shrill tones comes from un even gain or driver response.
If the distortion is bad enough it may make artifacts below the fundamental. In this case 7khz. These would be audible.
Is that 100pf cap for phono cart EQ?
If the distortion is bad enough it may make artifacts below the fundamental. In this case 7khz. These would be audible.
Is that 100pf cap for phono cart EQ?