M 249c

Common name: Neumann M 249c

Production Status: Discontinued / Vintage

The Neumann M 249c is a special version of the M 49c microphone with a RF shielded 7-pin Tuchel connector manufactured from 1964 until 1974. Although connectors are different there is no difference in powering. The M 49 is an high grade condenser microphone developed by Georg Neumann GmbH in partnership with the NWDR – Nordwestdeutscher Rundfunk (Northwest German Broadcasting) with the headquarters located in Hamburg. The M49 c in the latest revision of the original M 49. The M 49 is an high grade condenser microphone developed by Georg Neumann GmbH in partnership with NWDR – Nordwestdeutscher Rundfunk (Northwest German Broadcasting) with the headquarters located in Hamburg. The M49 b in the first revision of the original M 49. The NWDR engineers worked al lot with CMV 3 and U 47 models so they discovered the limits of these microphones in live broadcasts. The main limit being that it was necessary to approach the microphone in order to change the polar pattern. The other limit was that the microphone sensitivity changes with the polar pattern. Moreover they noticed that most of the dramas would have had benefits from different microphone patterns depending on the atmosphere and settings being described. The M 49 was developed to overcome these problems. It was the first remotely controlled pattern microphone, continuously variable between omnidirectional through cardioid to bidirectional while maintaining a practically constant sensitivity. The pattern can be changed by slowing rotating a control potentiometer without any switching noise. The microphone amplifier was designed in cooperation with NWDR’s engineering department just to achieve this. Georg Neumann designed the microphone with some further improvements that later became the standard for Neumann’s products. The dual diaphragm capsule was housed in a new shaped head grille for the purpose of avoiding diffraction and interference typical of previous cylindrical head grilles (refer to Stephen Paul’s piece about the effect of U 47’s head grille). The U 47 has only limited damping for the tube and the capsule holder. The M 49 amplifier is mounted on a rubber disk decoupling the amp itself from the microphone housing. The M 49 development started in 1949 and the microphone was presented to German broadcasters in 1952. The microphone received several revisions and it was in production until 1974. The “c” version is the latest one available, released in 1964. The first version is easily recognizable by the absence of the  Neumann logo, replaced by a “red gem”, while the M 49b and M 49c have the classic Neumann logo, and can only be distinguished by the microphone plate with the serial number. The M 49 “b” and “c” versions differ only in the different tube cathode coupling. The “c” version exhibits a 4 dB lower noise floor. The large dual diaphragm capsule is the K 49 with MCF gold plated diaphragms in place of the PVC M7. The output transformer is the Bv.11 with two secondary windings for 50/200 ohm nominal output impedance, wound with an electrostatic shield. The amplifier vacuum tube is the Telefunken AC 701 k. As the microphone was designed for broadcast applications its pre-amplifier circuit features built-in low and high frequencies attenuation. These microphones can be modified to achieve a full frequency response with lower phase distortion. The classic yoke mount holder isn’t a genuine Neumann accessory and it never was in the brand catalogue. It was manufactured by Danner – Berlin.

Electrical Characteristics

Frequency Response
40Hz - 16 kHz
Output Sensitivity
0.6 mV/Pa
Max SPL
125
Max SPL, THD:
0.5
Self Noise (CCIR)
dB
Self Noise (DIN/IEC)
dB-A
Output Impedance
50 or 200Ω
Recommended Load
1kΩ
Powering
Proprietary unit
Supply Current
mA
Alternative Powering
Tube Model
Telefunken AC 701

Switchable Options

Pad
Filter/EQ

Physical Characteristics

Connector
Tuchel 3462 (7-pin)
Connector notes
Available Colours
Satin nickel
Weight
800 g
Length
163 mm
Min diameter width
Max diameter
80 mm
Depth

Accessories

Included
Optional