Neumann M 147 Tube User manual

Product Information
Georg Neumann GmbH, Berlin • Ollenhauerstr. 98 • 13403 Berlin • Germany •Tel.: [phone] • Fax: [phone]
E-Mail: [email protected], [email protected], [email protected] • Website: www.neumann.com
M 147 Tube
Tube Microphone

he M 147 Tube is a vacuum tube condenser micro-
phone with cardioid characteristic. At the heart of this mi-
crophone is the K 47/49 dual diaphragm capsule, inherit-
ed from this model’s now legendary predecessors, the U 47
and the M 49.
Following the capsule is a tube that functions as an imped-
ance converter. The next stage is an efficient, transformer-
less output circuit, that guarantees an extremely low self-
noise level. Note: This innovative combination of current
tube technology with the most advanced solid-state circuitry
was decisive in awarding the 1997 TEC Award to the
related M 149 Tube mic.
The M 147 Tube can feed extremely long microphone
cables without affecting the quality of the audio signal.
Like all Neumann tube microphones, the M 147 Tube
comes with an elegant satin nickel finish.
The microphone is delivered as a complete set in a high-
quality aluminum case. Included with the microphone are
a microphone cable, a metal swivel mount for a mic stand,
and a compact universal power supply for standard mains
sockets. Our modern manufacturing methods makes it
possible to offer this complete set at a very attractive price.
Applications
The famous capsule, together with complimenting tube
characteristics, makes the M 147 Tube especially well suit-
ed as a vocal mic. In addition, it is a superb spot mic for all
types of musical instruments.
The extremely low self-noise of its tube circuitry makes the
mic perfectly suited for use in modern recording chains,
analog and digital.
Acoustic Features
The M 147 Tube is addressed from the side where the
microphone body has the diamond-shaped Neumann com-
pany logo. The black color identifies tube microphones.
The capsule is equivalent to the one used in the U 47, and is
the deciding factor in determining the sound characteristic.
It has a flat frequency response to the upper midrange, and
a boost of up to 3 dB above 2 kHz.
The headgrille design is a smaller version of the U 47. It pro-
tects the capsule effectively against popping and wind noise.
Polar Pattern
The M 147 Tube has a cardioid characteristic, leaning more
toward super-cardioid due to its distinctive capsule design.
At higher frequencies the pattern becomes more direction-
al. This is very similar to the model after which this new
tube microphone was patterned, the U 47 and the succes-
sor, the U 47 fet.
Delivery Range
M 147 Tube microphone,
N 149 A power supply incl. power cord, SG 1 swivel mount,
KT 8 microphone cable, dust cover, aluminium case
Catalog No.
M 147 Tube (230 Volt, Euro) ................................... ni .................... 08435
M 147 Tube (117 Volt, US) ....................................... ni .................... 08434
M 147 Tube (230 Volt, UK) ...................................... ni .................... 08436
Selection of Accessories
Power supply, N 149 V (EU) ............................................... 12253.00101
Power supply, N 149 V (US) ............................................... 12253.00201
Power supply, N 149 V (UK)............................................... 12253.00301
Elastic suspension, EA 1 .............................................. ni .................... 08449
Elastic suspension, EA 1 mt ...................................... blk .................. 08450
Auditorium hanger, MNV 87 ..................................... ni .................... 06804
Auditorium hanger, MNV 87 mt .............................. blk .................. 06806
Table stand, MF 3 ............................................................ blk .................. 07321
Table stand, MF 4 ............................................................ blk .................. 07337
Stand extension, STV 4 .................................................. blk .................. 06190
Stand extension, STV 20 .............................................. blk.................. 06187
Stand extension, STV 40 .............................................. blk.................. 06188
Stand extension, STV 60 .............................................. blk.................. 06189
Popscreen, PS 10 .............................................................. blk .................. 07345
Popscreen, PS 20 .............................................................. blk.................. 07346
Windscreen, WS 87 ........................................................ blk .................. 06753
Microphone cable, IC 3 mt ......................................... blk.................. 06543
A complete survey and detailed descriptions of all accessories
are contained in the accessories catalog
Meaning of color codes: blk = black, ni = nickel
Features
• Universal tube microphone
• Pressure gradient transducer with the large diaphragm capsule
from the legendary U 47 and M 49
• Transformerless circuitry
• Low self noise level
• Comes with swivel stand mount made of metal, universal power
supply, and cable in an attractive aluminium case
Application Hints
• Vocalist mic: its warm and yet transparent sound gives volume
and presence
• Announcer’s mic for broadcasting/voice over
• Spot mic for close miking of solo instruments, especially strings,
wind instruments, and piano
These are just some of the most common applications. We
recommend additional experimentation to gain maximum use
from this microphone.

Tube Microphone
M 147 Tube
Filter
The electronic circuitry of the M 147 Tube mic has a flat
frequency response from 20 Hz to well above 20 kHz. Only
the attributes of the capsule determine the typical sound
characteristics of the microphone.
N 149 A Power Supply
The N 149 A universal power supply works with all mains
AC voltages from 100 V to 240 V, 50 or 60 Hz. Mains
power is connected through a standard IEC 320
mains socket. The only difference between the
three versions of the M 147 Tube set is the
power cord supplied. Note: The N 149
and N 149 V power supplies that
come with the M 149 Tube are
fully compatible with the
M 147 Tube micro-
phone.
Electrical Features
When compared to other microphones, the impedance con-
verter used in the M 147 Tube is distinguished by its ex-
tremely low self-noise level of only 12 dB-A / 24 dB CCIR
weighted.
Similar to the recently introduced M 149 Tube, the new
M 147 Tube combines a specifically selected vacuum tube
(triode) with modern circuitry. This technique takes full
advantage of the special transfer characteristics of the tube
and passes the processed audio signal of the capsule to the
microphone output, without any coloration or unwanted side
effects.
The tube amplifies the capsule’s signal by approximately
10 dB, thus preventing any possible influences from subse-
quent electronics. The M 147 Tube delivers a high output
voltage, and therefore can feed microphone cables up to
300 m length without signal degradation.
The ideal operating conditions (anode current and heater
voltage) of the tube are maintained throughout its life ex-
pectancy. A sensor lead detects any voltage drop that
occurs through the microphone cable and compensates for
it in the N 149 A power supply.
The tube warms up gradually using inverse cur-
rent limiting to guarantee long life.
Operational Stability
Both, the capsule and the
entire circuitry are
shock mounted to
prevent any struc-
ture-borne
noise.
Because of
its wide oper-
ating range, the
M 147 Tube
can reproduce
extremely low
frequency signals
without distortion.
This implies that the micro-
phone may also be sensitive to un-
wanted LF interference by structure-borne noise, or wind
noise. To avoid possible signal degradation, we offer the EA 1
elastic suspension and the WS 87 windscreen as accessories.
During close miking of vocals we recommend using the PS 10
or PS 20 pop screen. You will find detailed information in
our accessory catalog.

Technical Data
Tube Microphone
M 147 Tube
Selection of Accessories
Table stand, MF 4 (in
connection with stand extension)
Stand extensions,
STV 4 /20 / 40 / 60
Table stand, MF 3 (in
connection with stand extension)Auditorium hanger, MNV 87 (mt)
Elastic suspension,
EA 1 (mt)
Power supply, N 149 V
(Vintage-Version)
Windscreen, WS 87Popscreen, PS 20Popscreen, PS 10 Microphone Cable, IC 3 mt
Acoustical operating principle ................................ Pressure gradient transducer
Directional pattern .................................................................................................... Cardioid
Frequency range ......................................................................................... 20 Hz...20 kHz
Sensitivity at 1 kHz into 1 kohm ................................................................... 20 mV/Pa
Rated impedance ...................................................................................................... 50 ohms
Rated load impedance .................................................................................... 1000 ohms
Equivalent SPL CCIR 468-3 ....................................................................................... 24 dB
Equivalent SPL DIN/IEC 651 ............................................................................... 12 dB-A
S/N ratio CCIR 468-3 .................................................................................................... 70 dB
S/N ratio DIN/IEC 651 ................................................................................................ 82 dB
Typical SPL (tube characteristic):
for < 0.5% THD (for < 5% THD) ........................................................ 114 (134) dB
Maximum output voltage .......................................................................................... 8 dBu
Dynamic range of the microphone amplifier:
DIN/IEC 651 for < 0.5% THD (for < 5% THD) ........................ 102 (122) dB
Powering ......................................................................................... Power supply N 149 A
Matching connector microphone ........................................................................ DIN 8F
Matching connector power supply .................................................................... XLR 3F
Weight ................................................................................................................................... 460 g
Diameter ........................................................................................................................... 57 mm
Length .............................................................................................................................. 142 mm

Errors excepted, subject to changes • Printed in Germany • Publ. 11/00 77225/A03