SERVICE MANUAL - Nexo

NXAMP4x44-7. Channel separation1) Ground the channel 2, channel 3 and channel 4 input terminals via a 600 Ω resistor.Input the 1 kHz, 0 dBu sine wave to the channel 1 input terminal and measure the output voltage obtained at thechannel 1 output terminal as the reference voltage (0 dB).Confirm that the output voltage at the channel 2, channel 3 and channel 4 output terminals is -65 dB or less ascompared with the reference voltage.2) Ground the channel 1, channel 3 and channel 4 input terminals via a 600 Ω resistor.Input the 1 kHz, 0 dBu sine wave to the channel 2 input terminal and measure the output voltage obtained at thechannel 2 output terminal as the reference voltage (0 dB).Confirm that the output voltage at the channel 1, channel 3 and channel 4 output terminals is -65 dB or less ascompared with the reference voltage.3) Ground the channel 1, channel 2 and channel 4 input terminals via a 600 Ω resistor.Input the 1 kHz, 0 dBu sine wave to the channel 3 input terminal and measure the output voltage obtained at thechannel 3 output terminal as the reference voltage (0 dB).Confirm that the output voltage at the channel 1, channel 2 and channel 4 output terminals is -65 dB or less ascompared with the reference voltage.4) Ground the channel 1, channel 2 and channel 3 input terminals via a 600 Ω resistor.Input the 1 kHz, 0 dBu sine wave to the channel 4 input terminal and measure the output voltage obtained at thechannel 4 output terminal as the reference voltage (0 dB).Confirm that the output voltage at the channel 1, channel 2 and channel 3 output terminals is -65 dB or less ascompared with the reference voltage.Note: Measure the output level with the 22 Hz-22 kHz band pass filter specified at 1-3.4-8. Output noise levelWith each input terminal grounded via a 600 Ω resistor, measure the noise level at each output terminal and confirm thatthe measured value is -56 dBu or less.Note: Measure the noise level with the 22 Hz-22 kHz band pass filter specified at 1-3.4-9. StabilityWith no load resistors connected to all output terminals, input the 1 kHz, +2.0 dBu square wave to all input terminals andmeasure the primary power consumption (Wno_load).With the 0.1 uF capacitor connected to all output terminals, input the 1 kHz, +2.0 dBu square wave to all input terminalsand measure the primary power consumption (Wcap_load).Confirm that the following equation is satisfied.Wcap_load-Wno_load = 60 W or less81