CMA-1XE Microphone Amplifier

The 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 recording applications.
Applications:
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.
The 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.
Features:
•  Single 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.
•  Red 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!
Specifications:
•  Frequency 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).
•  Input 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.
•  Attenuation: -46dB in 1dB steps, accuracy better than ± 0.2dB.
•  Output impedance: <1 ohm balanced and floating.
•  Max output level/headroom: +27dBu.
•  Phantom power: Switchable 48V by lockable toggle switch (silver contacts).
•  DC Power Indicator: Red LED +25 volt line.
•  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.
•  Dimensions (mm): 275(w) x 175(d) x 65(h) Weight: 1.5kg.
   Ref:  (0dBu = 0.775 volts RMS).