Yamaha mg8/2fx Service Manual page 25

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At the C-R OUT (L/R), setting the Level Control to the 12 o'clock position, feeding each 20Hz, 1kHz and 20kHz
signal, the distortion shall be less than 0.2%, when the output signal level is +3dBu.
*In the route (1), check every OUT when the signal is fed to CH1,and check only the ST L OUT when the signal is fed
to CH2 and other channels.
*In the route (2), turning the PAN/BAL control to L fully, the distortion shall be less than 0.1%, when the ST L OUT
signal level is +4dBu.
3.10 Maximum Output
In the state 3.1, the distortion factor shall be less than 1% when the output level is +20dBu at ST L OUT, ST R OUT,
SEND/EFFECT and C-R OUT.
The distortion factor shall be less than 1% when the output level is +7.5dBu at PHONES (L/R).
In measuring the ST L OUT, the ST R OUT, set the PAN or BAL Control to L or R fully respectively.
In measuring the C-R OUT and PHONES, set the C-R/PHONE Control to MAX.
3.11 Equivalent Input Noise
In the state 3.1, connect between the CH INPUT MIC terminals (2pin-Hot and 3pin-Cold) with 150Ω, the noise level
obtained at ST L OUT shall be less than -51.5dBu.
If it is over than -51.5dBu, calculate the input converted noise level (= noise level - channel gain) and it shall be less
than -127.5dBu.
Connect between the ST INPUT MIC terminals(2pin-Hot and 3pin-Cold) with 150Ω, the noise level obtained at ST
L OUT shall be less than -47.5dBu.
If it is over than -47.5dBu, calculate the input converted noise level (= noise level - channel gain) and it shall be less
than -123.5dBu.
(Noise is measured with a 12.7kHz -6dB/octave low pass filter.)
3.12 Residual Noise
In the state 3.1, set the Level Control of all input CH to MIN.
Then when the MASTER VR set to the MAX or MIN position, the noise level shall be less than the level specified in
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the Table 3.12-1.
*When measuring the C-R OUT and the PHONES, set the ST VR to MIN.
(Noise is measured with a 12.7kHz -6dB/octave low pass filter.)
Table 3.12-1 [Unit: dBu]
VR STEREO OUT
MAX -81.0
MIN -100.0
3.13 PHANTOM
Connect a 10kΩ load resistance between the pin 1 and 2 of the MIC and short-circuit between the pin 2 and 3.
Turn on the PHANTOM switch(LED shall light)and the voltage between pin 1 and 2 shall be within +35±3V.
3.14 DIGITAL EFFECT
EFFECT RTN switch ON and feed -30dBu signal to CH1 MIC.
The output level shall be over 0 dBu in the Table 3.14-1.
Table 3.14-1 [Unit: dBu]
OUTPUT CH1: GAIN VR
ST L OUT
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ST R OUT
Feed no signal and set the CH EFFECT level control and CH LEVEL VR to MIN.
The noise level of "ST OUT L/R"shall be less than -60dBu.
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EFFECT OUT
-85.0
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CH1: LEVEL VR
EFFECT VR
MIN MAX
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2 9
8
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C-R OUT
-87.0
-93.0
CH1: PAN PROGRAM select
R
L
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9 4 2 8
1 5 0 5 8 2 9 9 4
PARAMETER
switch
1
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MG8 / 2FX
9 9
2 8 9 9
MIN
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