Thanks to JAH for this one:
There has been some recent discussion on the differences of AKG 414's...It took me a bit but I dug up some old paper work and re-typed it so it could be added to the Archives.
Corey Eng wrote:
There have been a few AKG microphones which use the numbers 414 in them. I will try to list the one that I remember working on at the factory.
C412 & amp: C414 - Built in the early 70’s, came in two pieces, the stand adapter and the actual microphone. Came with the original brass capsule. It uses basically the transistor version of the CI2A, which a nuvistor tube (miniature tube). Instead of an external power supply it used phantom power (i.e 1248Vdc). Problem with this mi. was while the base of the microphone was metal the gill housing was made out of plastic. The mic. is prone to RFI if not modified and the plastic cracks if not taken care of.
C414EB — Introduced in the late 70’s (1977 or so), All metal construction (Silver housings). Early versions had the brass capsule while the later ones had the plastic injected type. In my opinion this is one of the better sounding microphones especially if it has an old brass capsule in it. The older boards have component problems over time the capacitors went bad. Once updated with current parts they should last a lifetime. Mic. Runs on 12 to 48Vdc phantom power. I believe the EB stands for Extended Bass.
C4141-EB/P48 — Introduced sometime in the early 80’s. It is at 48V phantom power version of the C414EB. Note this mic. Does not use the same PCB as the C414EB. The DC to DC converter is designed differently along with the pre-amp. The mic uses the plastic injected capsule. Housing is black. This mic is prone to RFI due to the way the frame was constructed. This problem is easy to fix and was in the later productions of this mic. This is an OK mic, but I still like the C414EB better.
C414B-ULS - Stands for Ultra Linear Series. This mic has a really flat frequency response. Superior DC to DC converter and pre-amp. This mic had been in production since the late 80’s. This is a wonderful mic and has a sound all to itself.
C414B-TI. —Exact same mic as the C414B-ULS except it uses and Capacitor instead of transformer at its output stag, this allows the mic. To reproduce frequencies lower than the C414EB-ULS. I remember one gentleman using this mic to record elephant movements in Africa.
C414B-TLII - Same mic as the C414B-ULS except it uses the TLII version on the CK12 capsule. Note: The plastic injected CK12 was designed to have flat frequencies response. The TLII capsule was designed to have a boost at the high end to emulate the sound the old brass CK 12 has.