CMA-1XE is an audiophile microphone pre-amplifier offering the highest standards
of performance. Designed to give a high level of microphone transparency with
ultra-low noise and distortion, providing consistently good sound over the whole
range of gain settings, with a precisely re-settable level control to cover all
The CMA-1XE is designed for
the discerning professional recording engineer. The microphone pre-amplifier is
a critical component in the recording chain, as it must take a low-level signal
from any of a wide range of transducers and amplify it so that it can be transmitted
to a recording or distribution system without loss of information or the introduction
of noise. To meet today's requirements for quality, particularly driven by advanced
digital media such as 192 kHz/24 bit DVD-A (192S), places huge demands on the
preamplifier electronics. The CMA-1XE has been designed to meet these challenges.
CMA-1XE is a pre-amplifier that can provide precise 1 dB gain adjustment with
minimal noise - it is designed to provide a very transparent signal path where
the original signal from the microphone is perfectly preserved and our precision
stepped attenuator allows exact gain matching of two or more amplifiers for use
with stereo microphones.
Using the CMA-1XE:
The CMA-1XE is a minimalist
microphone preamplifier. The original design by Andrew Gemmell-Smith
has been improved by Professional Sound Engineer Colin Attwell to
provide quality, integrity, transparency and EMI/RFI protection from mains-borne
interference, or external radiation from nearby transmitting stations and mobile
telephones. Consistent with this, each unit has only controls for the stepped
attenuator (guaranteeing repeatable gain levels on all recording sessions) and
for 48V phantom power. There are No filtering
or level monitoring circuits in this design.
24 pole Swiss ELMA-Mektron rotary switched attenuator for gain adjustment in 1
dB steps over two 23dB lockable switched ranges providing a total range of 46dB:
-76dBu to -30dBu.
• Audio inputs and outputs are via
gold pinned Neutrik XLR connectors.
• A lockable toggle switch
with silver contacts for 48V phantom power on/off.
• The RFI
Filtered mains input is via an IEC connector and battery power via XLR.
LED Power indicator.
• The unit is housed in a Deltron GP15
EMI/RFI sealed die cast box finished to RAL-35 Gray with all stainless steel/nylock
fittings and solid rubber screwed feet!
response: 20Hz - 20 kHz +0dB/-0.5dB.
• Equivalent input noise:
-131.3db 150 ohm (30Hz - 30 kHz).
• Distortion (THD): 0.009%.
• Common mode rejection: -100dB at 10 kHz (max gain).
impedance: >3k ohms balanced.
• Max input level: -10dBu.
• Gain Range: 30dB to 76 dB in two 23dB ranges, switched by
lockable toggle switch (silver contacts).
• Calibration: Range
'A' = -76dBu to -99dBu, Range 'B' -99dBu to 122dBu.
-46dB in 1dB steps, accuracy better than ± 0.2dB.
impedance: <1 ohm balanced and floating.
• Max output level/headroom:
• Phantom power: Switchable 48V by lockable toggle
switch (silver contacts).
• DC Power Indicator: Red LED +25
• External Battery Power: ± 15v, +48v via
XLR-4F (Male XLR fitted).
• Mains Power Supply: Via toroidal
transformer with conventional regulation.
• Mains voltage
specification: RFI Filtered 230v AC 50Hz 6VA EU (120v version also available).
• Mains Fuse: 20mm T100mA/250v screw fitting.
(mm): 275(w) x 175(d) x 65(h) Weight: 1.5kg.
(0dBu = 0.775 volts RMS).