The AK-47 MkI is a large diaphragm tube condenser microphone with a 9-way pattern selection switch on the power supply. The amplifier circuit was developed in partnership with AMI/TAB Funkenwerk and utilizes an AMI BV47 output transformer, a NOS TELEFUNKEN EF732 vacuum tube, and a TK67D capsule. This microphone was discontinued and replaced by the AK-47 MkII, which features an upgraded BV8 transformer (built to tighter tolerances and historic specifications than the original BV47), component upgrades, and wider circuit traces for better current handling and lower self-noise. The AK-47 MkII utilizes the same TK67D capsule as the AK-47 MkI, so sonically the frequency responses are similar, while the transient response, self-noise and current handling were all improved in the MkII design. The current production TF47 circuit is based on the AK-47 MkII.
Information on the current production TF47 can be found here.

