The microphone capsule photo and information thread

[pasarski]

Thanks, good news.

You don't have by any chance AOM 5024 or Primo EM 272 based mics to compare to?

The published S/N is not that great

No I have not tried those. I don't ever look the Ali specs, they are probably written by chatGPT My OPIC ( I call it Rogsophone) is so quiet that the preamp noise dominates.

 

[pmfalcman]

the Ali specs, they are probably written by chatGPT

You're too optimistic
BTW - I only trust these if they're bad.
And for this capsule S/N is 72 dB(A).

Sometime ago I happened there upon a SDC mic that's specced at S/N = 94 dB....
Somehow I do not believe this number.
But it's a great looking mic, tbh.

My OPIC ( I call it Rogsophone) is so quiet that the preamp noise dominates.

Hmmm.... It may mean that you have a lousy preamp
Just kidding. This is great news. Thank you!

Nb.: for some time I "walk around" OPIC thinking of building a pair

 

[pasarski]

Hmmm.... It may mean that you have a lousy preamp
Just kidding. This is great news. Thank you!

Actually the preamp has wonderful published noise spec of "Equivalent Input Noise@A-wt,150 Ohm | -130.5dBu" but of course it's a manufacturer's number so who knows?

 

[TimG]

The Mighty Rode NTK thanks to head basket fail.

 

[thomasdf]

I was doing some cleaning in my studio and thought I’d share some picture of a pretty rare Oktava microphone, the МКЭ-7. I have a matched pair and the paper manuals with all the infos, graphs etc. Beautiful !
Supposedly an Omni electret but it looks like an Omni SDC to me ?
Shame I haven’t use them a lot because they sounded a bit thin / harsh. I also never recapped them or opened until now. Maybe they sound better without the aluminium grid. I’d have to do some testing.

I am sure you capsule gurus will have clever insight to share

 

[Khron]

Supposedly an Omni electret but it looks like an Omni SDC to me ?

No bias voltage applied to the capsule, and why can't an electret have a "small diaphragm"?

 

[rock soderstrom]

No bias voltage applied to the capsule

It does, the capsule receives an external polarization voltage via R1 from the R2/R3 node. This is a source follower, very similar to the cathode follower in my current “The Electron” project.

 

[bremusound]

I don‘t think it‘s an omni capsule tbh. Frequency response doesn‘t fit and the lower part of the capsule construction would make no sense.

 

[thomasdf]

Well maybe I'm completely wrong ! I'll Google translate the manual and will report back

edit : unidirectionnal electret indeed !

 

[hop.sing]

The official frequency response looks like it is tailored for a close distance speech microphone. Looks a little bit like the one from the Schoeps mk40 capsule.