Specifications

32
Microphone Amplifiers
CMC 5Ug
for 48 V
phantom
powering
Microphone Amplifier CMC _
– flat frequency response
– extremely low noise and distortion
– balanced, very low-impedance output
– can be used with very long ca bles (se ve ral hund red
meters)
The capsules of condenser microphones (the only type
which we manufacture) can't be connected directly to
microphone cables or inputs; a microphone amplifier is
required in between. Thus a complete microphone of
the Colette series comprises any of the twenty available
types of capsules combined with an amplifier (e.g. a
CMC _).
The microphone amplifier provides the electrostatic
charge which the capsule requires in order to produce
a signal. Since only a miniscule amount of current is
contained in this signal, amplification of the current is
required. To avoid interference to the signal on the
way from the microphone to the input of the mixer or
preamp, the signal is conveyed at low impedance and
in balanced form. CMC amplifiers offer a symmetrical,
transformerless, direct-coupled Class A output stage
with low impedance, low distortion, and high freedom
from interference.
Powering Condenser Microphones
Since microphone amplifiers are electrically active, they
require a source of operating current. The prevailing
standard method for providing such current is known
as ”phantom powering.” There are two implementa-
tions: the 48-Volt version (which is widely used) and
the 12-Volt version, which is less often encountered.
We offer two microphone amplifier versions: the
more recent model CMC 6 (for standard 48- and 12-
Volt phantom powering) and the older model CMC 5,
which is exclusively for use with 48-Volt phantom
powering.
The circuitry of the CMC 6 recognizes the supply
voltage and adjusts itself automatically. Its perform-
ance characteristics remain essentially the same either
way; mainly, the difference is that the current drawn
at 12 Volts is greater than at 48 Volts. However, the
12-Volt mode is more efficient and might be preferred
for battery-powered recording.
CMC 5 or CMC 6? – A Guide for the Choice
The CMC 6 offers greater flexibility with regard to
powering as well as higher immunity to any radio-fre-
quency interference which may be radiated into a
microphone cable. For installations in which 48-Volt
powering will always be provided and in which RFI is
not an issue, the model CMC 5 is available.
With regard to audio quality the difference between
the CMC 5 and CMC 6 is quite small, and concerns
only the very lowest audio frequencies. The standard
versions of both amplifiers contain filters to guard
against inaudible infrasonic disturbances which could
lead to overload in a preamp or mixer, particularly if it
COLETTE
modular
CMC 6Ug
microphone amplifier
MK _
microphone capsule
Type designation of a complete microphone:
CMC 64 Ug
6 powering 12 V ± 1 V and
48 V ± 4 V phantom
4 capsule type MK 4
U connector XLR-3M
g surface finish matte gray,
non-reflective surface
finish