Primo EM50 measurement capsule

[k brown]

Anyone build anything with these? Same 1/2"capsule used for the Nakamichi CP3; heard various claims that Nak hand-selected them for the CP3, or had specially modified vesion made for them (?).

Same capsule was available with tiny body containing a 2SK118 FET and bias resistors, unterminated as EM4052PMI4.

 

[rogs]

It looks from the data sheets for currently available Primo capsules that the EM23 has the closest spec to the EM50 -- (except that it's quite a lot larger!) --
http://www.primomic.de/pdf/EM50.pdf
https://www.micbooster.com/documents/EM23.pdf
I've never come across either of those capsules 'in the flesh' as it were.
I have been very impressed with their EM200/204 larger diameter 'standard' electret capsules (with integral FETs) .....