System Verification
The procedure below is the same Final Test performed on MS Series units at the factory. Assuming there has been no apparent damage in shipment, it is not necessary to repeat it. However, it may be desirable to perform it as an initial confirmation of proper operation, as a periodic performance check, or whenever there is doubt about the unit’s operation.
Initial Setup
The following is done with NO audio or video input to the rear panel connectors.
1 . Set the VOLUME slider to mid position.
2. Plug External Supply into rear of chassis and corresponding AC outlet.
3. Verify that the BALLISTICS LED indicator is set to the VU setting.
4. Verify that the SPEAKER MUTE LED indicator is NOT illuminated.
5. Verify that the PHASE indicator LED is displaying GREEN.
6. Verify that the SIG LED indicators on the rear panel are OFF.
7. Set the REF/dBu button to +4 dBu; the +4 dBu LED should be illuminated.
8. Set the A/D SELECT to Analog; the Analog LED should be illuminated.
Check-Out
The following is done with audio input applied to the channels at the rear panel. The audio input should be a balanced, 0 dBu, 1 kHz continuous tone or burst. The test tone being used should be heard from the speakers, with the VOLUME slider set for a comfortable listening level.
1 . Verify that the test tone is heard from the speakers. Vary the VOLUME slider and verify that the signal goes from full off to full on throughout the slider control range.
2. Insert a stereo 1/4” headphone into the HEADPHONE jack and verify that operation is the same for the headphones for volume as it was for the speakers.
3. While monitoring the speakers, press the SPEAKER MUTE button to toggle from OFF to MUTE. Verify that the speakers are in fact muted. Return to the OFF position when done.
4. Assure that the VU/PPM metering indicator is displaying VU; if not, press the VU/PPM button so that the VU indicator LED is illuminated.
5. Set the audio source to +4 dBu and the REF/dBu button to +4, and verify for each channel that the Level Meters indicate 0 dB. Toggle the button to +8. The meter reading should drop to
6. Press the VU/PPM Select button and verify that the PPM LED becomes illuminated. Also verify that the meter reading increases by 6 dB and the meter response is more rapid in the PPM mode.
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