Yamaha EMX66M Service Manual page 38

EMX66M
3.2 For the case that the POWER AMP switch is 'MAIN BRIDGE'
3.2.1 Preparation
• POWER AMP switch: MAIN BRIDGE
• INPUT terminal: CH 5 LINE 1
• MASTER (MAIN): MAX
• OUTPUT terminal: BRIDGE
• Load Resistance: 8Ω(more than 600W)
Except otherwise indicated, the load resistance of SPEAKER should
be connected only for the amplifier check.
• LEVEL control of CH1-4, 6: MIN
• Except the above, same as the setting of 2.1
3.2.2 Gain Check
Apply -26.0dB signal into input terminal, and confirm that the output level of 22.0±2 dBs can be gained.
3.2.3 Frequency Response Check
Apply -26.0dBs signal into input terminal, and confirm that the output level for 20Hz, 20kHz signal are within +1, -3dB from the
level for 1kHz signal.
4. Miscellaneous
4.1 Power Supply Voltage Variation
Change the voltage of power supply in the range of ±10%, and confirm that the system works normally.
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Input
T
4Ω
Speaker
Resistor
Terminal
4Ω GND
Resistor
S
Level meter