Yamaha spx2000 Service Manual page 29

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INSPECTIONS
1. Preparations
1-1. Conditions
Use following conditions unless otherwise specified.
• INPUT VOLUME: MAX
• Level select switch: +4dBu side (both input and output)
• Analog output load: 600 Ω
• Word clock (FS): 96kHz
To select the word clock, press the UTILITY key several
times and when "CLOCK SOURCE" appears on the
LCD, press the INC/DEC key.
• 0dBu = 0.775Vrms
• 0dBFS = 0dB, full scale
• Oscillator output impedance: 150 Ω.
A sine wave is output.
• Input impedance of oscilloscope, level meter, etc.: 100
kΩ or more
• Noise measurement is corrected with 12.7kHz, -6dB/
octave low pass filter. (Use average values instead of
effective values for measurement.)
• Cross talk and distortion ratio measurement is corrected
with 80kHz, -18dB/octave low pass filter.
• For check items other than "2-7", turn on the BYPASS
TE
L 13942296513
key and keep the BYPASS LED lit while checking.
1-2. Measuring Instruments
• Use System Two CASCADE Control Software APWIN
Version 2.22 of Audio Precision Co. or its equivalent.
• Noise meter (Use LMV-1817 of READER Corp. or
the equivalent when measuring the noise.)
SPX2000
ANALOG IN
ANALOG OUT
AES/EBU IN
AES/EBU OUT
USB TO HOST
MIDI OUT
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1-3. Writing Programs
.
If the main program is not the latest version, it must be
upgraded to the latest program. For the details, refer to
"Method for Writing the Program" on page 49.
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SP
SP
SYSTEM TWO
WCLK IN
• Connect the powered
MIDI IN
speaker to the ANALOG
O U T t e r m i n a l w h e n
executing Test item 2-8
Sound Check.
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8
2. Check Items
2-1. When ANALOG INPUT/OUTPUT WORD
CLOCK is INT 96kHz
Condition:
Signals are inputted through ANALOG INPUT L, R
(XLR) and output from ANALOG OUTPUT L, R
(XLR).
[1] Gain (both L and R)
Connecting hot and cold terminals of OUTPUT L, R to
GND respectively provides the same result.
Input frequency
1 kHz
[2] Frequency response (both L and R)
Condition:
1kHz is used as reference of the permissible range.
Input frequency
[3] Level difference between left and right
The range of difference in the gain measured in [1] above
Q Q
3 6 7 1 3
is specified as follows.
[4] Residual noise (both L and R)
Condition: The input function should be turned off.
[5] Crosstalk between left and right
Condition:
The R channel input function should be turned off when
signals are inputted to the L channel.
The L channel input function should be turned off when
signals are inputted to the R channel.
Input frequency Output level L(R) Permissible range R (L)
1 kHz
2-2. When ANALOG INPUT/OUTPUT WORD
CLOCK is INT 48kHz
Condition:
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Signals are inputted through ANALOG INPUT L, R
(PHONE) and output from ANALOG OUTPUT L, R
.
(PHONE).
2 9 9 4 2 8
Input level Specified output level Permissible range
+4 dBu +14 dBu
Input level Permissible range
20 Hz +4 dBu -1． 5∼+0． 5 dB
40 kHz +4 dBu -1． 5∼+0． 5 dB
1 5 0 5 8 2 9 9 4
Permissible range
Within 1dB
Permissible range
-80 dBu or below
+22 dBu -58 dBu or below
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co
SPX2000
9 9
+14±2 dBu
2 8 9 9
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