Neumann.Berlin M 150 Tube Mode D'emploi page 3

After a few minutes, the tube in the microphone
will achieve a stable operating condition, and will
then exhibit extremely low self-noise.
The microphone is to be addressed primarily from
the side on which the Neumann logo is located.
Gradually increase the volume of the connected
equipment.
Set the gain of the connected equipment so that
no distortion occurs at the highest sound pres-
sure level.
Setting the pre-attenuation
The switchable pre-attenuation increases the
maximum signal level by 10 dB, in order to avoid
overloading when transmitting signals at ex-
tremely high sound pressure levels.
Pre-attenuation is activated by means of a switch
on the back of the microphone.
Setting the high-pass filter
The switchable high-pass filter can be used to
suppress low-frequency interference (e.g. caused
by impact sound or wind noise) or to compensate
for the proximity effect.
The high-pass filter is activated by means of a
switch on the back of the microphone.
Suppressing noise interference
The frequency response of the M 150 Tube extends
far below 0 Hz. The microphone is of course
correspondingly sensitive to low-frequency inter-
ference.
7. Troubleshooting
▶
Problem Possible causes
Microphone The power supply unit is not switched on.
not operating
The microphone is not connected to the
power supply unit or is not ready for
operation.
No signal The microphone is not connected to the
transmission correct microphone amplifier input of the
subsequent equipment.
EN
4
Extremely low-frequency signals can be gener-
ated by interference such as pop or wind noise. In
order to suppress such noise signals, we recom-
mend the use of a windscreen or popscreen from
our range of accessories.
Sound test
Simply speak into the microphone. Do not blow
into the microphone or subject it to pop noise,
since this can easily result in hazardous sound
pressure levels.
6. Shutdown and storage
Before switching off the microphone or discon-
necting the cables, reduce the volume of con-
nected equipment.
Only then should the power supply equipment be
switched off.
Disconnect the cables.
When disconnecting a cable, always pull only on
the connector and not on the cable itself.
Microphones which are not in use should not be
allowed to remain on the stand gathering dust. A
microphone which is unused for a prolonged pe-
riod should be stored under normal atmospheric
conditions, and should be protected from dust.
For this purpose, use a lint-free, air-permeable
dust cover or the original packaging of the micro-
phone.
▶
Solution
Check the connection to the power supply
line.
Check the LED status on the power supply
unit.
Check the signal path.
Check the corresponding channel settings.
8. Technical data and
connector assignments
Permissible atmospheric conditions: 1)
Operating temperature range ........... 0 °C ... +70 °C
Storage temperature range ........... –0 °C ... +70 °C
Humidity range ..................... 0 % ... 90 % at +0 °C
0 % ... 85 % at +60 °C
Acoustical op. principle .........pressure transducer
Directional pattern ........................omnidirectional
Frequency range ...............................0 Hz...0 kHz
Sensitivity ) ...............................................0 mV/Pa
Rated impedance ........................................50 ohms
Rated load impedance ..........................1000 ohms
Signal-to-noise ratio ,
)
CCIR .............................................................. 66 dB
4)
Signal-to-noise ratio ) ,
A-weighted 4) ................................................... 79 dB
Equivalent noise level,
CCIR ................................................................8 dB
4)
Equivalent noise level,
A-weighted 4) ................................................ 15 dB-A
Max. SPL (tube characteristic) 5)
for THD < 0.5 % ..............................................114 dB
for THD < 5 % ................................................. 14 dB
Dynamic range of the amplifier
A-weighted
4)5)
for THD < 0.5% ................................................ 99 dB
for THD < 5%...................................................119 dB
Max. output voltage ........................................ 8 dBu
Power supply ............................................... N 149 A
Required connectors:
Microphone .................................................... DIN8F
Power supply unit ..........................................XLR F
Weight ............................................................ 800 g
Dimensions ................................ Ø 78 mm x 165 mm
94 dB SPL equiv. to 1 Pa = 10 µbar
0 dB equiv. to 0 µPa
The 8-pin connectors of the microphone and the
power supply unit have the following pin assign-
ments:
Pin 1: −70 V
Pin : +5 V
Pin : Modulation (+phase)
Pin 4: +70 V
Pin 5: Sensor line
Pin 6: Ground
Pin 7: + V
Pin 8: Modulation (–phase)
The -pin XLR output of the power supply unit has
the following standard pin assignments:
Pin 1: 0 V/Ground
Pin : Modulation (+phase)
Pin : Modulation (−phase)
Circuit technology information
The operating point of the tube and the heating
voltage are stabilized by a control circuit in the
power supply unit. A sensor circuit detects and
compensates for voltage drops in the microphone
cable for cable lengths of up to approximately
100 m. Even a malfunction of this circuit due to
a short circuit or interruption is not hazardous,
since in this case the heating voltage is reduced
and all other operating voltages are switched off.
The tube is heated by means of inverse current
limiting, thus ensuring a long service life.
1) All values for non-condensing humidity. The values are
valid for clean and well-looked-after microphones or
microphone capsules, respectively. Any kind of pollution
of capsules and membranes may restrict the said values.
) at 1 kHz into 1 kohms rated load impedance.
re 94 dB SPL
)
4) according to IEC 6068-1;
CCIR-weighting acccording to CCIR 468-, quasi peak;
A-weighting according to IEC 6167-1, RMS
THD of microphone amplifier at an input voltage
5)
equivalent to the capsule output at the specified SPL.
5
EN