Yamaha AD8HR Service Manual page 54

AD8HR
TOTAL INSPECTIONS
1. SETUP
1-1. Conditions
Set as described below unless there are instructions otherwise.
Set the GAIN to 10dB and the WORD CLOCK INT to 96kHz.
Measure at DIGITAL OUT A (AES/EBU).
Input a signal only to the channel (hereafter CH) being measured.
When measuring NCH, check that a signal is input to NCH.
0 dBu = 0.775Vrms
0 dBFS = 0 decibels - fullscale
Set the output impedance of the oscillator to 150Ω.
Set the input impedance on the oscilloscope or level meter to 100kΩ or more.
In the noise measurement, correct with the Filter "A" WEIGHTING of System Two.
In the distortion measurement, correct with BW:FS/2 of System Two.
The EIN measurement should be made using the DA824 and MY8-AE cards and compensating (measuring the average
value not effective value) with an LPF of -6dB/oct at 12.7kHz, or should be the test using System Two and a conversion
value corrected with BW: 20kHz LP.
Do not initialize the system unless having any influence on repair. Measured value shows the Factory Preset condition.
When initializing the system, make sure to verify the data. Therefore, make sure to check the data. See "7. Factory
Settings" for the initialization. (P.57)
1-2. Connection
q
2. Testing with WORD CLOCK INT 96kHz
2-1. INPUT 1 - 8CH
q Gain
Input Frequency Input Level
+10dBu
-8dBu
1kHz -20dBu
-50dBu
-62dBu
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In case of using System Two
System
Two
DIGITAL
OUT A
AD8HR
GAIN Specified OUT level
+10dB
-8dB
-20dBFS
-20dB
(-2dBu)
-50dB
-62dB
w
In case of using DA824
Oscilloscope
Oscillator
Level meter
Rs=150Ω
Distortion meter
IN
DIGITAL
OUT A
MY8
-AE
AD8HR
DA824
※The internal gain SW
should be set to +18dB.
Tolerance Range
-20 ± 1dBFS
(-2 ± 1dB)
The number in the parentheses ( ) shows
the output of DA824.
OUT