Crosstalk; Peak And Signal Led Light-Up Level; Meter Led Lighting Check; Distortion Factor - Yamaha MG32/14FX Service Manual

MG24/14FX
MG32/14FX

4.7 Crosstalk

Set the GROUP1-4, ST and MONO master fader to the MAX position. At the input CH1, set the fader to the MAX position
and turn on the ON switch.
Turn the 1-2 assign switch ON and the PAN control (BAL control in the case of ST CH INPUT) counterclockwise fully.
When the signal of +20dBu is outputted to the GROUP1 OUT output, the level of the leakage into GROUP2 OUT output
shall be -50dBu or less. Also turning the PAN control clockwise fully, when the signal of +20dBu is outputted to the
GROUP2 OUT output, the level of the leakage into GROUP1 OUT output shall be -50dBu or less. The same is said of
relation between GROUP3 and GROUP4, ST L and R.

4.8 PEAK and SIGNAL LED light-up level

In the state 4.1, each PEAK and SIGNAL LED of input channel 1-24/32 shall light up when a signal specified as below
is fed to the input.
Table 4.8-1 [dBu]
INPUT
CH1-16/24
ST CH17-24/25-32 *
*1 Insert the jack to L and R both, and input a signal one side at a time.

4.9 Meter LED lighting check

Set the METER source select switch to GROUP position. PEAK LEDs shall lights up, when GROUP1-4 output level
reach +17.5 +/-2dBu.
0 LEDs shall lights up, when GROUP1-4 output level reach +4 +/-2dBu.
Operate the GROUP1-4 master faders and check that LEDs light up in order from "-20" to "PEAK".

4.10 Distortion Factor

In the signal routes of the Table 4.2.-1 to 4.2-12 indicated with ($), ($1), ($2) and ($3), set the VR and Fader of INPUT
and MASTER to the Nominal Position, and set the GAIN to the position specified in the Table (except PHONES).
Then, feeding each 20Hz, 1kHz and 20kHz signal, the distortion shall be less than 0.1 % when the output signal level is
+14dBu. At the PHONES OUT (L/R), setting the PHONES 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.
($1): Check GROUP1 and GROUP3 OUT when the signal is fed to CH1, and check only the GROUP1 OUT when
the signal is fed to CH2 and others.
($2): CH1 only.
($3): AUX1 only.
4.11 Maximum Output(@1kHz)
In the state 4.1, the distortion factor at 1kHz shall be less than 1% when the output level is +24dBu at ST L/R OUT, and
MONO OUT, and +20dBu at GROUP1-4 OUT, AUX1-6 OUT, EFFECT1-2 OUT, and ST SUB L/R OUT.
The distortion factor at 1kHz shall be less than 1% when the output level is +7.5dBu at PHONES (L/R).
In measuring the ST L/R OUT, the GROUP1-4 OUT and the ST SUB L/R OUT, set the PAN or BAL Control to L or R fully
respectively.
4.12 Equivalent Input Noise
In the state 4.1, shunt the CH INPUT A terminal with 150 ohms, set the ST assign switch and CH ON switch on, the ST L Output
noise level shall be less than -44dBu. If it is over than -44dBu, calculate the input converted noise level (= noise level - channel
gain) and it shall be less than -128dBu.
70
SIGNAL LED PEAK LED
-70 ±3 -43 ±2
-38 ±3 -17 ±2
1