32
TECHNICAL DESCRIPTION
The cartridge
Types 4003 and 4006 are omnidirectional (pressure) microphones
that use a 16mm diameter prepolarized condenser cartridge. The
diaphragm is a nickel foil which has been coated with an ultra-thin
polymer layer for optimum corrosion resistance. The microphone
housing is of German silver, an alloy with a high content of nickel to
match the stable thermal qualities of the diaphragm. The cartridge
has low self noise (typical 15dB(A) re. 20µPa) and high sensitivity
(4003: 40mV/Pa and 4006: 10mV/Pa). For optimum stability the
microphone cartridges have undergone a special pre-aging process
which stabilizes all tensions in the materials as well as the polariza-
tion voltage.
The preamplifiers
Types 4003 and 4006 are acoustically identical, but differ in their
preamplifier powering system. The 4003 is powered with 130V via
the HMA4000 High-Voltage Microphone Amplifier and has a modi-
fied 4-pin XLR-connector (see Fig. 1 for pin designation). This special
powering system enables the microphone preamplifier to handle
approximately 10dB higher SPL than similar microphone types pow-
ered through conventional P48 systems (4003: 154dB SPL peak
and 4006: 143dB SPL peak).
Furthermore the 4003 together with the HMA4000 is a totally
transformerless system and therefore has an extended low-fre-
quency handling capability (10Hz to 20kHz ± 2dB). The 4006 is pow-
ered via a standard P48 system and is equipped with a standard 3-
pin XLR-connector (see Fig. 2 for pin designation). Types 4003 and
4006 use state of the art low-noise preamplifier technology. The
preamplifiers are driven with unity gain to keep noise as low as pos-
sible.
All microphones come with an individual calibration chart of the self
noise, sensitivity and the individual frequency response.
Fig. 1. External view of the output socket of the Type 4003.
Fig. 2. External view of the output socket of the Type 4006.
Ground
Signal
4
3
2
1
130 V DC
Preamplifier Supply
Ground
Signal +
Signal -
3
2
1
Important:
The microphone will only operate within it's specifications if
powered correctly.
