Vintage Capacitor Dielectric

[VanguardAudioLabs]

This is something that's bugged me for a minute.

I see these in several mics i repair/service. Usually small values under 0.1uF, and often in the 10-1000pF range. Google Lens came up blank.

It would be weird for these to be ceramics in the audio path area (in this case, the RF filter caps in a Schoeps CMC5.), but they remind me of ceramics in size and capacitance values. These are 22nF/40V according to schem, but only marking is the 22n shown in photo.

Are these ceramics, or something else?

 

[rock soderstrom]

Are these ceramics, or something else?

I know this type of capacitor from vintage equipment. I think it's a ceramic capacitor, at least that's what I've believed for almost 40 years. But I can't give you a hundred percent guarantee.

 

[VanguardAudioLabs]

I know this type of capacitor from vintage equipment. I think it's a ceramic capacitor, at least that's what I've believed for almost 40 years. But I can't give you a hundred percent guarantee.

did a bit more digging and they SEEM like ceramics based on photos. Here's one example, although you know how it goes on the internet…

 

[JohnRoberts]

Vintage (old) capacitors that value and physical size are most likely ceramic. The only linear old ceramics (NPO/COG) were only available in small values (often across quartz crystals).

A RF filter is not passing the audio but if extremely non-linear can introduce IM distortion back down into the passband.

JR

 

[ToBSn]

This is something that's bugged me for a minute.

I see these in several mics i repair/service. Usually small values under 0.1uF, and often in the 10-1000pF range. Google Lens came up blank.

It would be weird for these to be ceramics in the audio path area (in this case, the RF filter caps in a Schoeps CMC5.), but they remind me of ceramics in size and capacitance values. These are 22nF/40V according to schem, but only marking is the 22n shown in photo.

Are these ceramics, or something else?
View attachment 142881

These are ceramic caps from Philips (BC):

Marking for Capacitance:
Capacitance value is indicated on the body, e.g. p56 for 0.56pF, 82p for 82pF, n15 for 150pF

Classification:
Class 1B: 0.56pF to 560pF
Class 2: 680pF to 10nF

Colour code of temperature coefficient ppm/°C:
The temperature coefficient is indicated by a colour code in accordance with IEC and EIA recommendations.
black = 0 (NP0)
red/purple = +100 (P100)
orange = -150 (N150)
purple = -750 (N750)
orange/orange = -1500 (N1500)
yellow from 680pF
blue from 6.8nF
green 22nF

https://shop.griederbauteile.ch/en/info/c/Capacitor/CAF2.pdf

 

[VanguardAudioLabs]

These are ceramic caps from Philips (BC):

Marking for Capacitance:
Capacitance value is indicated on the body, e.g. p56 for 0.56pF, 82p for 82pF, n15 for 150pF

Classification:
Class 1B: 0.56pF to 560pF
Class 2: 680pF to 10nF

Colour code of temperature coefficient ppm/°C:
The temperature coefficient is indicated by a colour code in accordance with IEC and EIA recommendations.
black = 0 (NP0)
red/purple = +100 (P100)
orange = -150 (N150)
purple = -750 (N750)
orange/orange = -1500 (N1500)
yellow from 680pF
blue from 6.8nF
green 22nF

https://shop.griederbauteile.ch/en/info/c/Capacitor/CAF2.pdf

This is incredibly detailed, tahnk you!