Lexicon RV-8 Service Manual page 39

Lexicon
Signal to Noise Test (SNR):
1. Using the signal levels from step 5 of the Frequency Response Test, turn off the oscillator and verify
a noise level measurement <-105dBr.
2. This procedure should be repeated to test analog inputs labeled 2 through 8. To do this, move the
cable from the output of the Low Distortion Oscillator to the next pair of inputs, and repeat the tests
above to test the remaining Main Zone RCA outputs. Repeat the above tests for the remaining Main
Zone amplifier outputs.
Digital Optical Input to Analog Output Test
This test will verify the specifications of the digital input and analog output circuitry.
Setup:
1. Connect a digital audio cable from the output of the Digital Function Generator to the S/PDIF optical
input 1 on the RV-8 rear panel.
2. Connect analog 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 S/PDIF INPUT OP1 TEST. Press the Menu
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 @ + 0dBFS to the S/PDIF coaxial 1 input of the RV-8.
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 Gain Test).
4. Verify that the output level measurement from the RV-8 is between the range of +3.28Vrms and
+3.63Vrms. 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 0.05%.
Frequency Response Test (FREQ):
1. Set the scale on the Distortion Analyzer to measure +1Vrms 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 100kHz.
5. Verify the signal levels are +0.10dBr to –0.5dBr (10/20Hz-20kHz), +0.10dBr to –0.2dBr (20Hz-
20kHz), +0.10dBr to –0.5dBr (40kHz), and +0.10dBr to –3.0dBr (100kHz) of reference level over the
entire sweep.
arrows, scroll through the Diagnostic Menu and select the AUDIO I/O TESTS.
arrow to
4-21