Equivalent Noise Level:
typ. 28 dB CCIR qps (NT 222 AC all switches "OFF",
"HARMONICS 0", M 222 measured with SCHOEPS
omni MK2S)
Noise level of the M 222 with NT 222 AC
All switches "OFF", "HARMONICS 0", no load
Common Mode Rejection: typ. 35 dB ("P 48": 50 dB)
Warmup Time:
20 seconds (before starting a recording wait 10
minutes until the tube has reached a stable
temperature to avoid thermal "clicks")
Cable KS 5 U:
The included microphone cable (5 m) is flexible and
has a low capacitance, gold-plated pins and a 100 %
shield. It can be extended by standard high-quality
stereo microphone cables (XLR 5).
Use of longer cables:
Using cables with a low capacitance (as all SCHOEPS
cables) it is possible to extend the enclosed KS 5 U
up to the following total length:
Connection M 222 to NT 222 AC: 20 m
Output NT 222 AC:
20 m
with "P 48":
200 m
For unbalanced operation the pins 3 and 1 of your XLR-3 cable may be bridged
at the end of the microphone's cable (next to your recording equipment).
Before switching on your NT 222 AC ensure that all volume controls are at
zero to avoid damages to loudspeakers or headphones.
CUT 150 Hz
:
This filter compensates the proximity effect of pressure-gradient transducers or
eliminates infrasonic signals caused by light wind. It cuts off frequencies below
150 Hz at a slope of 6 dB/oct. The exact corner frequency depends on the input
impedance of the following equipment. With the line driver "P 48" switched on
(see below) this filter will work as an infrasonic suppression below 30 Hz. With
the "CUT 150 Hz" switched OFF the frequency response will reach from 10 Hz
up to 30 kHz (depending on the capsule type).
UNBAL.
:
When connecting your Tube Microphone M 222 to an unbalanced input loss of
level may occur. You can avoid this by switching on "UNBAL." (for
unbal
anced
operation) or (maybe better near stronger magnetic or electrical fields) connect
- phase (pin 3 of your XLR-3) and ground (pin 1 of your XLR-3) close to your
recording equipment (with "UNBAL." switched OFF). But whenever possible you
should prefer the balanced mode ("UNBAL." in the OFF position) for it offers a
common mode rejection of at least 35 dB. This means the suppression of any
influenced magnetic disturbances.
HARMONICS
:
This switch alters the Q-point of the tube in 5 steps from "0" (off) to "4"
(maximum), causing the gradual increase of harmonics to set in earlier to
emphasize the typical tube sound.
CAUTION
: When switching this function put all volumes to zero as altering the
Q-point will always cause a strong crackle.
typ. harmonics vs. output level
from left to right:
HARMONICS
4
3
2
1
HARMONICS
OFF
-46 dB = 0,5 % THD
-60 dB = 0,1 % THD
0 dBV = 130 dB SPL (MK2S)
