Tim, since the point of this thread is to talk about how it all works--Neumann's LC 3 cables and other KM 100-series accessories are not active; their capsule heads are. That's why the interchangeable capsule heads for this series of Neumann microphones have the names "AK 20," "AK 30" etc.--the "A" stands for "active."
They are all built in two distinct parts (see attached photo)--the front part is the actual transducer, while behind it sits a little cylindrical barrel containing a FET and a couple of resistors. This same barrel is part of every active capsule head in this series. Its little circuit accepts DC power from the output stage (the "body" of the microphone) and delivers a fairly-low impedance, unbalanced signal to the output stage via the cable, gooseneck or tube--or directly, if no extension accessories are being used.
The output stage contains ICs and an output network to accept phantom powering and to convert the signal from the FET circuit to a balanced, low-impedance signal, which is then fed to the XLR connector.
--best regards
P.S.: Aside from the patent issues, the main practical difference between this approach and the Schoeps approach is that the Schoeps approach keeps the capsules simpler; if you want just the basic microphone and maybe some alternate capsules, but no active accessories, you don't pay any extra for the flexibility options. If you decide to buy a "Colette cable" or other active accessory then yes, that does become more expensive. But people don't tend to need many different active accessories, and it's nice to keep the cost of alternate capsules down to a dull roar.
The Neumann approach makes their extension accessories less expensive, but then every capsule has to include the extra cost of the special "active" element whether the customer intends to use extension accessories or not (many people don't). As a result Neumann's KM 100-series capsule heads are rather more expensive than they would be otherwise. If you own a pair of KM 100-series microphones and want to acquire capsule heads with other directional patterns, you end up paying for the multiple "active" elements even though you can use only two of them at a time. (Thus the KM 180 series exists ...)