Digital In To Analog Out Frequency Response Test; Thd+N Measurement; Analog In To Analog Out Thd+N Test; Analog In To Digital Out Thd+N Test - Lexicon 960L Service Manual

7. Move the Audio Input cable to Audio Input #2 and repeat the test.
8. Repeat the test on the remaining Input /Outputs pairs 3-4,5-6, and 7-8.

Digital In To Analog Out Frequency Response Test:

Note: Change the Clock Source and Inputs to AES - see Audio/Functional Tests Setup.
1. Disable all Filters on the distortion analyzer
2. Connect a balanced XLR audio cable between the digital function generator and the 960L # 1-2 AES
Input.
3. Connect a balanced XLR audio cable between the 960L # 1 Audio Output and the distortion analyzer.
4. Apply a 1kHz sinewave @ -1 dBFS.
5. Set the Analyzer for a 0dB reference (@1khz)
6. Sweep the oscillator from 20Hz to 20kHz and verify the level is +/- 1dBr throughout the sweep.
7. Move the audio output cable to the # 2 Output and repeat the test.
8. Repeat the test for the remaining Input /Outputs pairs 3-4,5-6, and 7-8.

THD+N Measurement:

Analog In to Analog Out THD+N Test:

Note: Change the Clock Source to Internal and Inputs to Analog - see Audio/Functional Tests Setup.
1. Connect a balanced XLR audio cable between the low distortion oscillator and the 960L # 1 Audio
Input.
2. Connect a balanced XLR audio cable between the 960L # 1 Audio Output and the distortion analyzer.
3. Apply a 997Hz sinewave @ 9.75 VRMS.
4. Set the distortion analyzer to measure THD+N.
5. Enable the Audio Band Pass filter on the distortion analyzer.
6. Verify the output THD+N on the Analyzer is < 0.002%.
7. Repeat the rest for the remaining Input /Outputs 2-8.

Analog In to Digital Out THD+N Test:

1. Connect a balanced XLR audio cable between the low distortion oscillator and the 960L # 1 Audio
Input.
2. Connect a balanced XLR audio cable between the 960L # 1-2 AES Output and the digital distortion
analyzer.
3. Apply a 997Hz sinewave @ 10.94 VRMS.
4. Set the distortion analyzer to measure THD+N.
5. Enable the Audio Band Pass filter on the distortion analyzer.
6. Verify the output THD+N on the Analyzer is < -94 dBFS.
7. Move the audio input cable to the # 2 Input and repeat the test.
8. Repeat the test for the remaining Input /Outputs pairs 3-4,5-6, and 7-8.

Digital In to Analog Out THD+N Test:

Note: Change the Clock Source and Inputs to AES - see Audio/Functional Tests Setup.
1. Connect a balanced XLR audio cable between the digital function generator and the 960L # 1-2 AES
Input.
2. Connect a balanced XLR audio cable between the 960L # 1 Audio Output and the distortion analyzer.
3. Apply a 997Hz sinewave @ -1 dBFS.
4. Set the distortion analyzer to measure THD+N.
5. Enable the Audio Band Pass filter on the distortion analyzer.
6. Verify the output THD+N on the Analyzer is < -94 dBFS.
7. Move the audio output cable to the # 2 Output and repeat the test.
8. Repeat the test for the remaining Input /Outputs pairs 3-4,5-6, and 7-8.
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