Yamaha XP1000 Service Manual page 26

XP1000/XP2500/XP3500
INSPECTION
Scope
This inspection specifications is applied to the power amplifier XP1000/XP2500/XP3500.
1. Power Source/Frequency
Destination
U, T
H, B, K, O
A
2. Preparation for STEREO/PARALLEL mode
Attenuator
Input terminal
MODE switch
GAIN switch
HPF switch
Load resistor
Unless otherwise specified, the operation shall be both channels drive.
Unless ohterwise specified, the input signal shall be high quality sine wave.
3. Inspection and Adjustment
3. 1 POWER LED, PROTECTION LED and Power on muting time
POWER LED and PROTECTION LED shall light when the POWER switch is turned on.
2.5 +/- 1 seconds after the power switch is turned on, PROTECTION LED shall lights off.
3. 2 Fan and TEMP LED
The fan shall operate when short circuit on the two jumper wires that mounted of DC circuit board marked "FAN-C".
The TEMP LED shall lights up when short circuit on the two jumper wires that marked "TM-C".
3. 3 Idle current
Connect the input terminal to the GROUND and adjust VR101(channel A) and VR102(channel B) on the PA UNIT so
that the DC voltage of Vb between the pin1 and pin2 of CN108(channel A) and the CN107(channel B) shall be 0.5 +/- 0.1mV.
After finishing all inspections, adjust the Vb again to 0.5 +/- 0.1mV.
3. 4 DC Voltage of output terminal
Connect the input terminal to the GROUND and measure the DC voltage Vdc of the output terminal shall be 0 +/- 75mV.
3. 5 Gain
3. 5. 1 Nominal Gain
The output voltage should be +22.0 +/- 0.5dBu when input signal is 1kHz, -10.0dBu.
3. 5. 2 GAIN switch
Set the Gain SW to 26dB.
With 1kHz -10dBu input signal, the output voltage shall be +16.0 +/- 0.5dBu.
Set the GAIN switch to +4dBu.
With 1kHz -10dBu input, the output voltage shall be as following table.
XP1000
+17.2 dBu
+/-0.5 dBu
3. 5. 3 Attenuator
Set the input attenuator to -10dB.
With 1kHz -10dBu input signal, the output voltage shall be +12.0 +/- 3.0dB.
3. 5. 4 PARALLE MODE
Set the MODE switch to PARALLEL.
Apply 1kHz -10dBu signal to input terminal of channel A.
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Input signal must not be applied to input terminal of channel B when PALLEL MODE.
At this time, the output voltages of both channels shall be +22.0 +/- 0.5dBu.
Voltage Frequency
+2
120 V %
-0
+2
230 V %
-0
+2
240 V %
-0
"0"(MAX) (Both Channel)
cannon type connector: 2PIN-HOT/3PIN-COLD/1PIN-GND
STEREO
32dB
OFF (Both Cannel)
8 Ω +/- 1%
XP2500
+21.2 dBu +22.7 dBu
+/-0.5 dBu
60 Hz
50 Hz
50 Hz
XP3500
+/-0.5 dBu