Neumann M 149 Tube

The polar pattern switch selects one of nine directional patterns: omnidirectional, wide-angle-cardioid, cardioid, hypercardioid, figure-8, and one additional intermediate pattern between each major position.

 The circuit of the M 149 Tube microphone has been developed to exceed traditional designs. We have selected a modern tube (triode) and combined its exceptional transmission characteristics with the advantages of our proven transformerless output circuit.

The aim was to provide a more controlled environment for the audio signal on its path from the capsule to the output section.

The final stage is an integrated amplifier, especially designed for such applications. It features very low distortion (THD < 0.002 % at ± 10 V), very low self-noise, and high output current capability.

As a result, the tube circuit is completely decoupled from the microphone output and its characteristic response curve will be unaffected by very high signal levels or varying load conditions.

The lower output impedance and higher output current capability allow cable lengths up to 300 m (1000 feet) without any degradation of the audio signal.

The tube amplifier changes the high impedance of the capsule and adds 10 dB of gain to the audio signal, providing optimum operating specifications. The wide dynamic range is impressive, as peak output can be ±10 V, at 20 mA.

The ideal operating point of the tube is maintained throughout its entire life expectancy. Plate current and filament voltage are constantly regulated. A sensor circuit monitors and compensates for any voltage drop across the microphone cable. The tube is heated up slowly through inverse current limiting to guarantee long life. Optimum operating conditions are reached within a very short time.

A seven-position slide switch is located on the back of the microphone. It selects a high-pass filter, advancing in half-octave steps between 20 Hz and 160 Hz (-3dB). This filter is useful to suppress rumble from air-conditioning and in windy situations.

In addition, the filter provides an effective tool to control the audio signal when the microphone is used at close distance and therefore proximity effect alters the program material. 

The specifically designed N 149 A power supply unit feeds the M 149 Tube through an 8-core cable. The output connector for the audio signal is a 3-pin XLR. The output signal is balanced.

The microphone comes as a set in an attractive aluminium case, together with the 8-core microphone connecting cable, the N 149 A power supply with plug-in mains unit, the EA 170 full elastic microphone suspension and a dust cover.
*The design of the microphone is a registered design of the Georg Neumann GmbH in certain countries. 

Switchable tube microphone

Transformerless circuitry

High output level

Pressure gradient transducer with the M 49 capsule

Acoustically very open wire mesh cage

Nine directional characteristics: omni, wide angle cardioid, cardioid, hypercardioid, figure 8, and one intermediate position each

7fold switchable low frequency roll-off

 

Technical Data

Acoustical operating principle	Pressure gradient transducer
Directional pattern	Omnidirectional, wide angle cardioid, cardioid, hypercardioid, figure-8 plus one intermediate position each
Frequency range	20 Hz ... 20 kHz
Sensitivity at 1 kHz into 1 kohm	34/47/62 mV/Pa1)
Rated impedance	50 ohms
Rated load impedance	1 kohms
Equivalent noise level, CCIR2)	28/25/23 dB1)
Equivalent noise level, A-weighted2)	16/13/11 dB-A1)
Signal-to-noise ratio, CCIR2) (rel. 94 dB SPL)	66/69/71 dB1)
Signal-to-noise ratio, A-weighted2) (rel. 94 dB SPL)	78/81/83 dB1)
Typical SPL (tube characteristic)3)	K < 0,5 %: 120 dB, K < 5 %: 136 dB
Maximum output voltage	18 dBu
Powering	Power supply N 149 A
Matching connectors	Microphone DIN8F, Power supply XLR3F
Weight	730 g
Diameter	70 mm
Length	201 mm
______________________________________________ 1) Omnidirectional / cardioid / figure-8 2) according to IEC 60268-1; CCIR-weighting acccording to CCIR 468-3, quasi peak; A-weighting according to IEC 61672-1, RMS 3) measured as equivalent el. input signal

 

Accessories

Adapter Cable AC 25
Auditorium Hanger MNV 87 (mt)
Boom Attachment M 212 c
Elastic Suspension EA 170 (mt)
Floor Stand MF 5
Microphone Cable IC 3 mt
Microphone Cable KT 8
Popscreen PS 15
Popscreen PS 20 a
Power Supply N 149 A
Stand M 210/1
Stand M 214/1
Stand M 252
Stand Extension STV 4/20/40/60
Table Stand MF 3
Table Stand MF 4
Vertical Bar MZEF 8060/8120