Since 1988 Josephson has been making state-of-the-art interchangeable small diaphragm condenser microphones for demanding sound pickup applications in our Series Six. These have all been custom products, and during 2004 and 2005 we are picking the best of the custom designs and making them available in regular production. Each of the microphones consists of a capsule and a body. It's our design approach to make the microphone electronics inside the body be as neutral as possible, leaving all the "character" (or lack of it) to the capsule. While this is wonderful theory, the real world of interaction with cables and other electronics makes it necessary to offer several different versions of the electronics for different purposes.

Microphone capsules supplied so far have included

• KA11 omnidirectional
• KA21 subcardioid/wide cardioid
• KA22 cardioid
• KA22S side-address cardioid
• KA24 cardioid, low frequency rolloff
• KA25 hypercardioid

Microphone bodies are

• C603A Original transformerless active-balanced output, 1988-1998
• C604A Like C603A but for T12 (Tonader, AB or parallel) power 1989-1998
• C606A Like C603A but with new cascode front end circuit for improved dynamic range 1995-2003
• C606B Like C606A but with high voltage polarize output and housing for half-inch instrumentation capsules 1996-2004
• C609 Cascode FET front end coupled with advanced Lundahl transformer output, used in the e22S microphone 1995-current
• C610 Vacuum tube version - never put into production due to lack of reliable, quiet tubes
• C617 Second generation version of C606B. Stabilized 200 volt polarize output and lower noise. 2004-current
  While the older models are no longer available, Josephson continues to support all types with spare parts, calibration and upgrades as needed.
  
  Why so many types of electronics? We're looking for the absolute maximum dynamic range, but this sometimes requires other compromises. For instance, our C606 range has a very low output impedance, and fairly high output levels. This combination doesn't play well with some older transformer-based input stages. We developed the C609 body with our cascode FET front end circuit and custom Lundahl output transformer for these applications.