Yamaha MR816CSX, Руководство по обслуживанию

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MR816CSX/MR816X
46
<2-11> Headphones volume attenuation
Set up as in description marked 4 in procedure
<2-1> (P. 44).
Set up as follows.
Headphones 1, 2 volume: MIN
Unit: [dBu]
Unit: [dBu]
<2-12> Hi-Z
Set up as in the following table.
Input signal from CH 1 with unbalanced system.
Turn ON the [Hi-Z] switch of CH 1.
Check that the difference of output levels between
the output level when a 500 k Ω resistor is
connected in series to the signal line compared to
the output level before connecting the resistor is as
follows:
<2-13> Phantom
With the No. 2 and No. 3 pins of the [MIC/LINE
INPUT 1 ‒ 8] terminal shorted, connect a resistance
load of 10 k Ω between the No. 1 and No. 2 pins.
Turn ON the Phantom function of the channel to be
measured.
Refer to "• P48V" in procedure 5-1-3-1 (P.
43) for the way to turn on the Phantom function.
Check that the voltage applied to the resistor is
within the following range.
5-1-3-3. Digital characteristic inspection
Set 0 dBu = 0.775 Vrms, 0 dBV = 1 Vrms and 0 dBFS
= +18 dBu.
<1> Preparations
•
Load resistance
Load resistance of each output terminal should be as
follows:
[OUTPUT 1 – 4]
: 600 ohms
• Input/output terminals
[INSERT I/O 1, 2]:
Unconnected
• Controller settings
Unless otherwise speci fi ed, set up as follows.
• CH INPUT
GAIN volume (CH 1 – 8)
: MIN
[PAD] switch (CH 1 – 8)
: OFF
[Hi-Z] switch (CH 1)
: OFF
[+48V] switch (CH 1 – 8)
: OFF
• Muting Circuit [QUICK CONNECT 7,8]
Mute: OFF
Controllers which are not described above can be set to
any settings.
• Input signal
Use 1 kHz sine wave for input signal unless otherwise
speci
fi ed.
Input the following signals to the INPUT terminals.
• Setup of measuring device
Don
'
t set up the fi lter of the measuring device unless
otherwise speci fi ed.
• Notice
If a result of test related to noise (distortion, mute) is
NG, execute factory set and then test again. (Refer to
"
FACTORY SET
"
on P. 40)
<2> Digital I/O test
<2-1> ADAT (OPTICAL) test
• Set the MR816CSX/MR816X to the ADAT ⇔
Analog audio connection setup for checking.
(Refer to "• Audio connection" in procedure
5-1-3-1 (P. 42))
• Connect the [adat IN] terminal and [adat OUT]
terminal to be in loop connection.
<2-1-1> Gain (MIC input)
Set up the GAIN volumes [1
‒
4] and [PAD] switches
as in the following table.
Unit: [dBu]
INPUT
Headphones 1
L R
CH1
-80 or less
‒
CH2 ‒
-80 or less
INPUT
Headphones 2
L R
CH3 -80 or less ‒
CH4 ‒
-80 or less
Voltage
+35 +/-3 V
MIC/LINE INPUT
1–4
System Balance
Source
Impedance
150 ohm
Input CH1
LEVEL
GAIN PAD
OUTPUT 1 LEVEL
DIFFERENCE
-25 dBu
(Unbalance)
MAX ON -6 +/-1 dB
INPUT
INPUT
LEVEL
GAIN PAD
OUTPUT
1 – 4
MIC/LINE
INPUT
1 – 4
-16 MIN ON -22 +/-2
-60 MAX OFF +4 +/-2 (*4)
1
2
←
←