Yamaha MR816CSX Service Manual page 46

MR816CSX/MR816X
<2-11> Headphones volume attenuation
Set up as in description marked
<2-1> (P. 44).
Set up as follows.
Headphones 1, 2 volume:
INPUT
L
-80 or less
CH1
CH2 ‒
INPUT
L
CH3 -80 or less
CH4 ‒
<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:
Input CH1
GAIN PAD
LEVEL
-25 dBu
MAX
(Unbalance)
<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 "• Phantom +48V" 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.
Voltage
+35 +/-3 V
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] :
46
4 in procedure
MIN
Unit: [dBu]
Headphones 1
R
‒
-80 or less
Unit: [dBu]
Headphones 2
R
‒
-80 or less
OUTPUT 1 LEVEL
DIFFERENCE
ON -6 +/-1 dB
600 ohms
• Input/output terminals
Unconnected
[INSERT I/O 1, 2]:
• Controller settings
Unless otherwise specifi ed, set up as follows.
• CH INPUT
GAIN volume (CH 1 – 8) :
[PAD] switch (CH 1 – 8) :
[Hi-Z] switch (CH 1) :
[+48V] switch (CH 1 – 8) :
• Muting Circuit [QUICK CONNECT 7,8]
Mute:
Controllers which are not described above can be set to
any settings.
• Input signal
Use 1 kHz sine wave for input signal unless otherwise
specifi ed.
Input the following signals to the INPUT terminals.
MIC/LINE INPUT
1–4
System Balance
Source
150 ohm
Impedance
• Setup of measuring device
Don ' t set up the fi lter of the measuring device unless
otherwise specifi 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.
INPUT
INPUT GAIN
LEVEL
MIC/LINE -16 MIN
INPUT
1 – 4
-60 MAX
MIN
OFF
OFF
OFF
OFF
Unit: [dBu]
OUTPUT
PAD
1 – 4
1
ON -22 +/-2 ←
2
←
OFF +4 +/-2 (*4)