A 'fix' for microphonic polystyrene caps.

[JohnRoberts]

At that time (late 70s), I knew them as NPO ceramics. Didn't know what COG was until this Millenium. They were cheaper than small polystyrenes and at first, we looked down on them until we discovered the microphony and production problems with polystyrenes.

I am disappointed in myself if these were available, cheaper, and better than polystyrene capacitors (or as good). I'm cheap. I used lots of these in my old kit business.

I recall early this century struggling to source some audio quality capacitors that would survive surface mount reflow. I tried some film SMD parts (Panasonic IIRC?), but my contract manufacturer managed to melt them, literally. It seems only fairly recently (decades) that NP0/COG ceramic parts have become available in large enough values for practical audio filter use.

Cheap ceramic caps were held in low regard because some of the dielectrics were rather nonlinear. COG/NP0 have done wonders for ceramic's reputation.

JR

PS: Hows it going down under?

 

[ricardo]

Am guessing this has been discussed before, but I am wondering if some of the canonical microphones would have used styrene if C0G was available, maybe I have dates flipped though...

The microphony is part of the signature sound of these 'canonical' mikes. A subtle way to add an extra sheen, air, clarity & definition to the sound ... and NO. I'm not joking

It's like the fact that ALL Golden Pinnae amps have subtle bursts of oscillations on real speaker loads made more complex by signal and thermal history. No wonder they sound different.

 

[ricardo]

PS: Hows it going down under?

Still alive though feeling the effects of old age. Loadsa health issues. No more swimming with crocodiles though still swimming with sharks

 

[k brown]

Still alive though feeling the effects of old age. Loadsa health issues. No more swimming with crocodiles though still swimming with sharks

You mean you still post on Gearspace?

 

[jp8]

Something like these, perhaps?

https://khronscave.blogspot.com/2024/07/86-condenser-cavalcade-akg-perception.html

Yes, indeed! I actually have this mic, but forgot I posted pics in another thread a while ago. It's indeed not a tight fit as Krohn posted, but it does touch the inner wall of the tube, so I would expect it would reduce PCB vibrations. This mic is sitting idle here, so I removed the foam and checked microphony by putting it in my faraday cage and tapping on the box. Didn't notice much difference. Stuffing some foam in the mic at the high-Z area works pretty good.

Jan