Yamaha MR816x, Руководство по обслуживанию

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MR816CSX/MR816X
44
• 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 filter of the measuring device unless
otherwise speci
fi ed.
• Notice
If a result of test related to noise (distortion, equivalent
input noise, crosstalk, mute, residual noise, etc.) is NG,
execute factory set and then test again.
(Refer to "FACTORY SET" on P. 40)
<2> Analog test
Set the MR816CSX/MR816X to the AD/DA through
setup (AD/DA, Digital Input/Output audio connection) for
checking. (Refer to "
•
Audio connection" in procedure
5-1-3-1 (P. 42))
<2-1> Gain (MIC input)
Set up the GAIN volumes [1 – 8] and [PAD] switches
as in the following table.
Unit:[dBu]
Unit:[dBu]
*1:
Check that level differences between OUTPUT 1 –
8 channels and Headphones [1, 2] L/R channels are
as follows:
<2-2> Gain (LINE input)
Perform the same test as the 1 of procedure <2-1> .
<2-3> Frequency Characteristics
Set up as in description marked
2
and
4
in
procedure <2-1>.
Check that the level of each output when the
frequency is 20 Hz and 40 kHz are within the range
shown below compared with the level when the
frequency is 1 kHz.
<2-4> Distortion
Set up as in description marked
1
and
3
in
procedure <2-1>.
Then, adjust input level so that output level is as in
the description below:
Check that the distortion of outputs is as follows:
Unit:[dBu]
Unit:[dBu]
* Use 22 Hz HPF and 30 kHz LPF.
<2-5> Equivalent input noise
Set up as in description marked
2
in procedure
<2-1>.
Connect 150 Ω resistor to the input terminals as
follows:
MIC/LINE INPUT 1 ‒ 8:
Between pin 2 (Hot) and pin 3 (Cold)
Measure the output level at the [OUTPUT 1 ‒ 8]
terminals.
Check that the noise levels are as follows:
Unit:[dBu]
* Use 22 Hz HPF and 30 kHz LPF.
<2-6> Output residual noise
Set up as in description marked 1 and 3 in
procedure <2-1>.
Measure output levels with no signal input.
Check that the noise levels are as follows:
Unit:[dBu]
* Use 22 Hz HPF and 30 kHz LPF.
MIC/LINE INPUT
1 – 8
System Balance
Source
Impedance
150 ohm
INPUT
INPUT
LEVEL
GAIN PAD
OUTPUT
1
‒
8
MIC/LINE
INPUT
1 – 8
-16 MIN ON -22+/-2
-60 MAX OFF +4 +/-2
(*1)
1
2
INPUT
INPUT
LEVEL
GAIN PAD
HEADPHONES
1, 2
MIC/LINE
INPUT
1 – 4
-16 MIN ON -32.9+2/-3
-60 MAX OFF -6.9 +2/-3
(*1)
3
4
Tolerance
2 dB or less
Tolerance
1/-3 dB
OUTPUT LEVEL
OUTPUT 1 – 8 +4
Headphones 1, 2 -6.9
OUTPUT Distortion
OUTPUT 1 – 8 0.03% or less
Headphones 1, 2 0.1 % or less
INPUT OUTPUT 1 – 8
MIC/LINE INPUT 1 – 8 -46 (EIN: -110)
OUTPUT 1 – 8 Headphones 1, 2
Noise Level
-80 or less -80 or less
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