Bose FreeSpace IZA 2120-HZ Service Manual page 122

4. Input Signal Clip Level Test
4.1 Apply a -36dBV +/- 3.5dBV, 1kHz sine wave to the RCA input jacks.
4.2 Verify that the Input Signal / Clip LED on the front panel is lit GREEN.
4.3 Apply a +10dBV +/- 2dBV, 1kHz sine wave to the RCA input jacks.
4.4 Verify that the Input Signal / Clip LED on the front panel is lit RED.
5. Output Signal Clip Level Test
5.1 Apply a +1.5dBV +/- 2.5dBV, 1kHz sine wave to the RCA input jacks.
5.2 Verify that the Output Signal / Clip LED on the front panel is lit GREEN.
5.3 Apply a +35.0dBV +/- 2.5dBV, 1kHz sine wave to the RCA input jacks.
5.4 Verify that the Output Signal / Clip LED on the front panel is lit RED.
100V Output Mode Tests
•
Set the 70V / 100V output switch to 100V output.
• Connect the amplifier outputs to 83 ohm, 250W loads.
1. Output Gain Test
1.1 Place the Input Mode switch to the Dual position.
1.2 Apply a 1kHz, 0.5dBV sine wave to the RCA input jacks.
1.3 Measure the output level. Verify that it is +40.0dBV +/- 0.5 dBV.
1.4 Measure the THD+N level. Verify that it is < 0.3%.
2. Frequency Response Test
2.1 Apply a -20dBV, 1kHz sine wave to the RCA input jacks. Adjust the signal input level to
provide a 1W output across the 42 ohm loads. Reference a dB meter to this output level.
2.2 Change the input frequency to 55Hz. Measure the output level. Verify that it is -3dBr
+/- 1dBr.
2.3 Change the input frequency to 18kHz. Measure the output level. Verify that it is -1.5dBr
+/- 1dBr.
3. Signal to Noise Test
3.1 Apply a 0.5dbV, 1kHz sine wave to the input RCA jacks. Verify that you have a 120W output
from both channels.
TEST PROCEDURES
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