Alto L-12 Service Manual page 46

Remarks: the frequency response test of normal instruments:
a. Turn EQ LOW knob of the relating channel clockwise to the max (+15), the
output is +15dBu(± 2dB), then turn EQ LOW knob of the relating channel
counter-clockwise to the min. (-15), the output is –15dBu(± 2dB);
Input the signal at 2.5kHz, Turn EQ MID knob of the relating channel
b.
clockwise to the max (+12), the output is +12dBu(± 2dB), then turn EQ MID
knob of the
relating channel counter-clockwise to the min. (-12), the output is –
12dBu(± 2dB);
c. Input the signal at 15kHz, Turn EQ HIGN knob of the relating channel clockwise to
the max (+15), the output is +15dBu(± 3dB), then turn EQ HIGH knob of the relating
channel counter-clockwise to the min. (-15), the output is –15dBu(± 3dB);
4. test DSP
a. Input the signal from MIC1, output the signal from MAIN MIX OUTPUT, turn
AUX RTN2(DFX)clockwise to the MAX, turn PRESETS and VARATIONS knobs,
the signal will be processed by DSP, if the level of the signal is over-high, PEAK
LED will be illuminated to red, press DFX MUTE button, Bypass the signal, press
the footswitch, which is connected to DFX FOOSWITCH, the signal will get out of
BYPASS.
b. Input the signal from MIC 1 to MIC 4, output the signal from AUX SEND S1, turn
AUX 2 /DFX TO AUX 1 counter-clockwise to the MAX., turn PRESET and
VARATIONS knobs, the signal will be processed by DSP. (do not need to test L6
with this step)
5. Sampling test
Connecting L 6 to a power amplifier and speakers, listening to the sound, no noise is OK.
Company preset: turn all volume knobs to the MIN. other control knobs to the middle,
all switches to the position of OFF.
DONE
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