RadioBanter - View Single Post - Voltage sensitivity of ceramic capacitors

Ralph Mowery · October 27th 18, 11:00 PM posted to uk.radio.amateur,rec.radio.amateur.homebrew

In article alpine.LNX.2.20.1810271206170.5141@thrush,
says...

Interesting thread over in rra.boatanchors suggesting that
ceramic capacitors' capacitance is voltage sensitive and
thus responsible for distortion in the audio path.

Since it's audio, won't the capacitance values be high enough that you're
more likely to use electrolytics in the audio path?

I got most of that started when I asked a question about someone
replacing paper capacitors with the ceramic disk in an old transmitter I
bought.

As the discussing is in boatanchors, it is mainly assumed to be old tube
equipment, which is what I have. Values around .01 to .1 mfd are often
used in the signal path. The impedances of the tube circuits are often
half a megohm and up. Outside of filter capacitors about the only place
in an audio circuit for electrolytics is in the cathode resistor bypass
where that resistor is usually under 500 ohms of tube circuits.

If lower impedance of transistors, then the value of the capacitors are
often high enough to go to electrolytics.