ATT. -10dB
:
The Tube Microphone M 222 accepts sound pressure levels up to 142 dB without
attenuation. Output voltage then can reach 10 V rms (measured with SCHOEPS
omni MK2S, without load). This could overload your microphone inputs. Switching
on "ATT. -10dB" will reduce the output level with the maximum sound pressure
level remaining the same.
P 48
:
In the "OFF" position there are no semiconductors whatsoever in the signal path of
the M 222 with the NT 222 AC. This offers pure tube technique without
transformers or transistors. Output impedance then is about 500 that allows
microphone cables up to 40 m total length. For operation with longer cables and/or
use in strong magnetic fields you can switch on "P 48" adding a class-A
transformerless and condenserless solid state output stage with an output
impedance of 50 for cables up to 200 m. This line driver is powered by the
phantom power (12V - 48V) of the following microphone input.
This means
: "P 48" is only possible when your equipment offers phantom-power.
But with "P 48" OFF you can use
any
microphone input (phantom-powered or not,
balanced or not, high or middle impedanced, even parallel feeding is possible - but
for best results we recommend to switch off any powering).
Technical Data M 222 with NT 222 AC
:
Mains voltage:
220 V (180 .. 240 V), one fuse 50 mA slow
110 V (90 .. 120 V), two fuses 50 mA slow
Change of mains voltage: Inside the NT 222 AC there
are two sockets for fuses.
Plug in
one
fuse
between
the sockets for 220 V or
two
fuses
into
the sockets for 110 V.
On the PCB you will find further hints.
Power consumption: ca. 3 VA
Max. Output Level: 10 V
eff
(switches "OFF", "HARMONICS 0", no load)
Indicators:
green LED: "ON"
(mains on)
red LED:
"P 48"
(line driver on)
yellow LED: "UNBAL." (unbalanced operation)
Microphone Powering: Heating 4 V (open loop 5 V), anode voltage 60 V
Output Impedance: 500 ("P 48": 50 )
transformerless, balanced or unbalanced
Load Resistance:
min. 1 k ("P 48": 600 )
no damage by open loop or short circuit
Pin Assignment:
Input:
Pin 1 GND
Pin 2 + phase M 222
Pin 3 - phase M 222
Pin 4 + 4 V (open loop + 5 V)
Pin 5 + 60 V
Output: PIN 1 GND
PIN 2 + phase
PIN 3 - phase, may be bridged with PIN 1
for unbalanced operation ("P48" OFF)
Overall dimensions: 57 mm x 105 mm x 145 mm, metal case, Nextel gray
