Audio Performance Verification - Lexicon RV-8 Service Manual

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AUDIO PERFORMANCE VERIFICATION

Performing these tests assures that the audio signal paths in the RV-8 meet published specifications.
These tests will verify the performance specifications of the gain, frequency response, THD+N, and S/N
ratio of each channel.
Analog Audio Inputs To Main Zone RCA Outputs Test
This test will verify the specifications of the Main Zone RCA outputs.
Setup:
1. Connect an audio cable between the output of the Low Distortion Oscillator and the RV-8 left RCA
input 1.
2. Connect an audio cable between the front left RCA output of the RV-8 and the input of the Distortion
Analyzer.
3. Using the Menu /
4. In the AUDIO I/O TEST menu, highlight AUDIO INPUT 1 TEST. Press the remote control Menu
arrow to engage the test. The RV-8 is now set to route audio from the left and right RCA inputs
labeled 1 to all RCA analog outputs.
Gain Test (GAIN):
1. Apply a 997Hz signal @ +4Vrms to the RV-8 left RCA analog input 1.
2. Set the scale on the Distortion Analyzer to measure +8Vrms signal level.
3. Turn all the filters off on the Analyzer (Filter not required for this test).
4. Verify that the output level measurement from the RV-8 is between the range of +3.10Vrms and
+3.70Vrms. Note this level.
Total Harmonic Distortion Test (THD):
1. Adjust the scale on the Distortion Analyzer to measure 0.01% THD+N and turn off the low-pass or
audio band pass filter.
2. Verify that the THD+N measured on the Analyzer is less than 0.09%.
Frequency Response Test (FREQ):
1. Set the scale on the Distortion Analyzer to measure a +4Vrms signal level.
2. Using the output level from step 4 of the Gain Test, set the Distortion Analyzer for a 0dB reference to
check frequency response of the RV-8.
3. Turn the filter on the Analyzer off.
4. Sweep the oscillator frequency from 10Hz to 40kHz.
5. Verify the signal levels are +0.10dBr to –0.8dBr (10Hz-20Hz), +0.10dBr to –0.25dBr (20Hz-20kHz),
and +0.10dBr to –0.8dBr (20kHz-40kHz) of reference level over the entire sweep. Note these levels.
arrows scroll through the Diagnostic Menu and select the AUDIO I/O TESTS.
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