# Option Board 4 Ch Microphone Inputs Option Board 4 Ch Microphone Inputs (O\_AIX\_4MIC\_a) #### Analog Inputs - 4 channels - Connector type = D-Sub25 female connector - Microphone or line input operation - Microphone mode @ 150 Ohm load: - input-impedance mic: 9 kOhm, electronically balanced - gain range: -10 dB (Pad), 0 dB, 10 dB ... 65 dB - phantom power: +48 V DC, individually switchable per channel - frequency response @ 48 kHz sampling rate: +/- 0.1 dB, 11 Hz to 22 kHz - dynamic range @ 10 dB gain: 115.3 dB RMS unweighted, 118.0 dB A-weighted - equivalent input noise: -128 dB - Line mode @ 40 Ohm load: - input-impedance line: 20 kOhm, electronically balanced - Common data: - analog line channel to channel isolation, 20Hz to 20kHz @ 10 dB gain: min. 118 dB - THD+N @ -3 dBFS, 1 kHz, 10 dB gain: 0,00075 % - THD+N @ -3 dBFS, 1 kHz, 40 dB gain: 0,0075 % - THD+N @ -3 dBFS, 1 kHz, max gain: 0,020 % #### Connector DB-25 Pin Assignment

Pin (Female Connector)	Function
1	Not Used
2	Ground
3	Not Used
4	Not Used
5	Ground
6	Not Used
7	Input 4 +
8	Ground
9	Input 3 -
10	Input 2 +
11	Ground
12	Input 1 -
13	Not Used
14	Not Used
15	Not Used
16	Ground
17	Not Used
18	Not Used
19	Ground
20	Input 4 -
21	Input 3 +
22	Ground
23	Input 2 -
24	Input 1 +
25	Ground