Neumann KM75

Translated from the Neumann KM-series manual.

Like other microphones in the KM70 series, the KM75 is solid-state and transformerless, with a circuit shared with the KM73 (omnidirectional) and KM74 (cardioid).

The microphone operates on 7.5–14 V DC T-power and is housed in a compact, nickel-plated cylindrical body terminated with either a 3-pin DIN (Tuchel) connector or XLR output.* It is designed for use in professional broadcast and recording applications, particularly in environments where high directionality is required.

The small microphone KM 75 is a special version of the KM74. The frequency response shows a steady drop after the low frequencies, which at 50Hz is about 12 dB. As a result, the microphone is not very sensitive to low-frequency noise.

It is therefore used preferentially for close-up use and for outdoor recordings. The capsules of the microphones KM73. KM 74 and KM 75 are mechanically the same. The individual types can thus be converted into each other by exchanging the capsules. The name of the capsules is KK 73. KK 74 and KK 75. For identification, the capsule KK 73 is marked with a surrounding ring, the capsule KK 75 with a dot. The capsule KK74 does not carry any special markings.

* The XLR version is denoted KM75i.

Acoustic Operation: Pressure gradient receiver

Characteristic: Cardioid

Frequency range 40–20,000 Hz

Field operating transfer factor at 1 kΩ: approx. 2.5 mV/μbar

Electrical termination resistance: 1000 Ω

Electrical internal resistance (impedance): 200 Ω

Capsule capacitance approx. 37 pF

Equivalent loudness (dB re 2x10^-4 μb): approx. 27 dB

Noise voltage (DIN 45 405): ≦ 11 V peak value

Limit sound pressure level for 0.5% total harmonic distortion at 40 Hz, 1 kHz and 5 kHz: ≧200 µbar

Operating voltage: 12 V (+1 V/- 4.5 V)

Current consumption: approx. 7 mA

Operating time with battery devices: ≥ 20 hours

Weight: 90 g

Dimensions: 21 + 24 mm diameter. 145 mm long

The KM75 brochure can be found through Neumann's excellent File Finder website.