K67 and K87 differences

[AV]

Hello
I am new in this DIY world and wish to know the main differences between a Neumann K67 and K87 capsules.
I know that K67 is a not isolated one and K87 have two isolated backplates but, what means this in terms of usability?

I explain myself. Can I use both capsules in all circuits? May I, in exemple, modify the G7 mic project that plan to build if I use a K67 or a K87 capsule?

 

[dmp]

You can tie the two backplates together in many cases - there are a few designs that rely on isolated backplanes for the different patterns (elam 251 for instance)

The G7 won't have a problem with that BUT the G7 is a flat amplifier. The k67/87 capsules have a treble boost and then a rolloff in the U67/87 amplifier to compensate.

So use a flat capsule in the G7 (i.e. U47/C12)

 

[Delta Sigma]

I believe K87 is designed for lower voltage (phantom power). No idea what voltage would cause membrane collapse though.

 

[wave]

In my experience the K67 and the K87 are the same hardware and geometry, the difference being that the K87 has isolated backplates (from each other) and the Kk67 has connected backplates. You could use them interchangeably in a circuit if you know when to connect or isolated the backplates. It would be difficult to take K67 and make it work like a K87 as the K87 has insulated shoulder screws for the backplate connection hardware. These screws are custom made by/for Neumann and I have never seen them in an OTS part. If you could find some M1.4 nylon screws, those could work.

-Dave

 

[AV]

Thank you very much, guys, for the replies.
I have 3 K67 capsules that I put in 2 CAD GXL300 micrphones and the other was planning to put in a vintage U87 clon but technician said me that is not possible.
The vintage circuit need a isolated blackplate capsule.
If I put the k67 (not isolated) it could not be polarized correctly and it only will works in cardioid mode.

Someone told me that the first U87 uses K67 capsules, so I do not understand why the U87 vintage clon can not works with my U67.