Crosstalk Tests; Analog In To Digital Out Crosstalk Test; Digital In To Analog Out Crosstalk Test; Dynamic Range Tests - Lexicon 960L Service Manual

960L Multi-Channel Digital Effects System Service Manual

Crosstalk Tests:

Analog In to Digital Out Crosstalk 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. Enable the Audio Band Pass filter on the distortion analyzer.
5. Verify the level on AES Output #2 to be < -100 dB throughout the sweep.
6. Move the Input cable to the # 2 Input and repeat the test for AES Output #1.
7. Repeat the test for the remaining Input /Outputs pairs 3-4, 5-6, and 7-8.

Digital In to Analog Out Crosstalk 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 # 2 Audio Output and the distortion analyzer.
3. Apply a 997Hz sinewave @ -1 dBFS.
4. Enable the Audio Band Pass filter on the distortion analyzer.
5. Verify the level on Output #2 to be < -100 dB throughout the sweep.
6. Move the audio output cable to the # 1 Output and repeat the test.
7. Repeat the test for the remaining Input /Outputs pairs 3-4,5-6, and 7-8.

Dynamic Range Tests:

Analog In to Analog Out Dynamic Range 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 @ 24dBu.
4. Set the distortion analyzer for a 0dB reference.
5. Enable the Audio Band Pass filters on the distortion analyzer.
6. Lower the input by 60dB to -36dBu.
7. Verify the THD+N at the # 1 output to be <-110 dBr.
8. Repeat the test for the remaining Input/Outputs 2-8.

Analog In to Digital Out Dynamic Range 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 @ 24dBu.
4. Set the distortion analyzer for a 0dB reference.
5. Lower the input by 60 dB to -36dBu.
6. Verify the THD+N level at the # 1-2 AES Output to be <-110 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 Dynamic Range Test:

Note: Change the Clock Source and Inputs to AES - see Audio/Functional Tests Setup.
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