Akai AS-8100

AUDIO
SIGNAL
GENERATOR
AS-8100
120W 8
DUMMY LOAD RESISTOR
Fig. 20
Supply output from the Audio Signal Generator to
the various “Aux” output terminals of Model
AS-8100. Connect a dummy load resistor equip-
ped with resistor value switch to the various
speaker output terminals as shown in Fig. 20 and
connect this output terminal to the Oscilloscope
input terminal.
Turn EPC Operating Point Adjustment Semi-Fixed
Resistor VR-1 (1 KB) fully clockwise.
Set Mode Selector Switch to “Stereo” and set
dummy load resistor switch to 8Q position. Adjust
volume control to obtain an undistorted oscillo-
scope waveform of maximum value.
At this condition, set dummy. load resistor switch
to “2.7Q” position and turn operating point
adjustment semi-fixed resistor VR-1 counter-clock-
wise to the point at which the output waveform is
erased and from this point, turn clockwise again
about 20° from erased point. With a 2.7Q dummy
ioad resistor, the waveform will appear as shown in
Fig. 21.
Set Mode Switch to “Surround” and manipulate
Surround Balance Shift to check whether or not
EPC functions. If EPC functioned during this
check, turn EPC operating point adjustment semi-
- fixed resistor slightly further clockwise.
SPEAKER
OUTPUT
VI.EPC (ELECTRONIC PROTECTION CIRCUIT )
ADJUSTMENT
DUMMY LOAD
RESISTOR OSCILLOSCOPE
Fig. 19
Fig. 21 Waveform when the dummy
load resistor is 2.7Q
In the check outlined in item 5), if EPC did not
function, try shorting the various speaker output
terminals. Check to confirm that no matter which
terminal is shorted, EPC functions. When making
this check, even if a single waveform is not erased,
turn EPC operating point adjustment semi-fixed
resistor slightly further clockwise.
When EPC functions regardless of which speaker
output terminal is shorted, EPC adjustment is
perfect.