Neumann.Berlin fet 80R (i) Supplement Manual

Neumann-Information 1841
NOV.
I 984
Operation of NEUMANN fet 80R(i) microphones in conjunction with unba-
lanced or Center tap grounded inputs
The
microphones of
the fet 80 R
(i) series are
Phantom
powered from
48
Vdt
according to IEC 268-15A/DIN 45, 596.
In
Phantom
powering
both modulation
conductors
of the
microphone cable as
-weil as the modulation leaving the power supply
are at the powering voltage
potential of +48 Vdt.
For
professional balanced and floating
amplifiers and
console inputs this is of no consequence.
However
when such Phantom
powered
microphones
are
connected to inputs
which
have side
or the Center
tap
grounded,
the
powering voltage is shorted
out and no
Operation
is possible.
For Center tap grounded
equipment with an input
transformer
(e.g.some NAGRA
NAGRA
recorders),
this
Center
tap
ground tan virtually always
be
discon-
nected without causing any negative
operational results.
For
connection af NEUMANN fet 80 R
microphones to
unbalanced inputs,
there are
the following possibilities:
1.
Microphone
and
power
supply may be
operated
without any
alterations
even
into unbalanced
or Center
tap
grounded inputs, if a
high quality
cable
transformer (1
:l
turns ratio)
of the AT 8/1
(i)
type is
inserted
into
the modulation
line.
Since there are numerous
types of
microphone
input
connectors,
this
transformer
is supplied with stripped and tinned
secondary leads only.
A specific
connector will
be attached
to the secondary
on
special Order
and at additional
price.
The maximum input Signal
capability
of the AT 8/1 (i) is 300 mV at 40 Hz;
frequency range is
30...16,000
Hz.
Fig.
1
Bu 1
5u 1 +--20cm
4 b--
30cm
---+
INTERNATIONAL
DIN
PRIMARV
SEKUNDARV
i
.
- MICROPHONE
(150.. 250a.h)
Bu 1
Bu 1
;NTEANATIONAL
DIN
0
ty$ AT811 i
Soldering side vietq
Fiq. 1
GN7
CHARLOTTENSTRASSE 3 . D-l000 BERLIN 61 I POSTFACH 610469 . TELEGRAMM: NEUMANNACUSTIC
TELEFON: (030) 25993-0 . TELEFAX: (030) 25993-108 . TELEX: 184595 NEUAK D
Printed in Germany