Tascam MMR-8 - Manual (Page 130)

TASCAM MMR-8 Owner’s Manual • Chapter 8 • Maintenance and Service 130
MIC Calibration Procedure
Follow this step-by-step procedure to calibrate the MMR-8 Input Converters (MIC).
1. Get out of the Reference Tone mode by pressing the SETUP key. Go to menu 530. Press TRIM and
use the Wheel to select the Off menu selection. Press STO to turn off the tone. Press the STOP
switch. Press CLR to exit Setup mode.
2. Press INPUT and turn on all channels for monitor input by pressing SEL on each track (all eight Input
LEDs should be turned on).
3. Connect a cable from the audio analyzer output to MMR Input connector, channel 1, at the rear of the
unit. Set the audio analyzer output to be a sine wave with a level of +4 dBu. Also connect the audio
analyzer input to MMR Output channel 1. (The next step assumes the user wants a unity system gain
with an input clip level of +24 dBu. The full scale (CLIP) adjustment range is from +9 dBu to
+25 dBu. )
4. While monitoring the channel 1 output level, adjust the Input board channel 1 trimpot for an output
level reading of +4 dBu (+/-.05 dB). This equals 1.228 Vrms (+/-.025 Vrms) measured at XLR pin
2(+) and 3(-) pins.
5. Move the audio analyzer output and input to the next channel. Repeat step 4 for each channel
6. Turn off the power. Replace the top cover on the MMR. Remove the calibration cables.
End of the analog input level calibration procedure.
Analog Converter cards location within the MMR-8 chassis (top view).
Input Converter Board Output Converter Board