Microphone Preamplifier / Audio Distribution Amplifier
A System 1000 Module

MDA-101PA - Mic-Pre Power DA™

The MDA-101 combines an ultra-low-noise, variable gain microphone preamp with a DA. It has one input and 10 line level outputs. It provides the ideal method of microphone signal distribution, because all signals are distributed at line level. Since input clip is +29 dBu at minimum gain, the card is a good choice for line level distribution applications that occasionally require significant gain. With line level distribution, long runs are far less susceptible to noise pickup from lighting or other sources, and line level inputs are all that is needed at the receive end. Plug on accessory daughterboards, such as the RGC-04 remote gain control, add significant versatility to the DA. Join the BBC, NBC-TV, NPR, and the Boston Symphony in choosing the finest mic-pre DAs!

The MDA-101PA-ra module is a MDA-101PA with remotely controlled attenuator.

Features

• 1 dB noise figure, -130 dBu EIN
• Gain range from -2 to +73 dB (with pad)
• CMRR > 100 dB to 2 kHz, 75 dB @ 20 kHz
• Bandwidth = 160 kHz, 20 kHz Ø = -8°
• THD < 0.001% @ 2 kHz, 0.0035% @ 20 kHz
• Virtually no intermodulation distortion
• 3 types of mic power; +48 & +12 V phantom, AB/T
• Common mode input filter for RF immunity
• Ten 60 ohm balanced outputs
• Remote input pad option
• Optional daughterboards available

THD+N and Phase vs. Freq Performance Graph

Larger image of MDA-101PA

The FSG-01 is a First Stage Gain control daughterboard for the MDA-101, a System 1000 microphone preamplifier - line level DA. The FSG-01 performs gain change directly at the input stage of the microphone preamp thereby optimizing the noise and distortion performance of the preamp. By placing the actual gain change at the first stage of a microphone preamplifier, the noise figure and distortion performance of the preamp is maintained. VCA gain control is often placed in the third stage of a preamp, however this is a compromise to overall distortion and noise performance as well as making first stage clip condition correction impossible without a remote input attenuator.