Triple Dig Input Module
Airlab from D&R Phone +31 294 418014, email:
info@d-r.nl
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Mono Microphone input
The front end of this module is designed to amplify balanced microphone signals. A +48 Volt phantom
power supply is available for condenser microphones. The Airlab has the ultimate in mic amplification with
a wide dynamic range and extremely low noise.
The microphone input is electronically balanced and protected against R.F. interference.
Input impedance is 2 kOhm. This is high enough to accept all modern microphones.
The Gain control can vary the input levels with a range of 40dB in one turn.
The signal to noise ratio is -127.0 dBr and is therefore well suited to low noise applications.
Phantom Powering
This +48 Volt power is required for condenser microphones and can be applied to the microphone inputs
via a jumper setting on the PCB. (See also chapter 12)
When the phantom power is applied and the channel is active, a 'click' can be heard when a microphone is
plugged in. This is due to a D.C. component on the input, which is suddenly interrupted and amplified by +/-
70 dB. It's therefore important NOT to do this with channel faders up and channel ON. It's even better to
switch of the console entirely before connecting or disconnecting any kind of equipment.
DO NOT use unbalanced or electret microphones when the phantom power is applied as it could damage
the microphones.
High-Pass Filter on MIC
The high-pass filter attenuates the low frequencies below 80 Hz and can be switched on or off by jumper
settings (see also chapter 12). It is only active on MIC inputs.
NOTE: Some microphones have built in high-pass filters and therefore do not require use of the
Airlab high-pass filter.
Microphones used for speech are usually set for high-pass filtering in order to avoid 'popping' and other
unwanted low frequency rumble and therefore improve the quality and intelligibility of the spoken word.