Owner's Manual

8-EN
SWITCH SETTINGS
• Before switching each Selector Switch, turn off the power and insert a small screwdriver, etc.,
perpendicularly to the Switch.
(Front Side)
(Rear Side)
Input Gain Adjustment Control
Set the R-A90S input gain to the minimum
position. Using a dynamic CD as a source,
increase the head unit volume until the output
distorts. Then, reduce the volume 1 step (or until
the output is no longer distorted). Now, increase
the amplifier gain until the sound from the
speakers becomes distorted. Reduce the gain
slightly so the sound is no longer distorted to
achieve the optimum gain setting.
Crossover Mode Selector Switch
(CHANNEL-1/2)
a) Set to the “OFF” position when the
amplifier will be used for driving
full range speakers or when using
an external electronic crossover.
The full frequency bandwidth will
be output to the speakers with no
high or low frequency attenuation.
b) Set to the “HP” position when the
amplifier is used to drive a tweeter/
midrange system.
At this setting, Crossover Frequency
Adjustment Knob (
) provides
adjustment between 50 Hz to 400
Hz. The frequencies below the
crossover point will be attenuated
at 12 dB/octave.
NOTE:
• In this case the maximum Bass EQ
boost level is reduced.
c) Set to the “HP-H” position when the
amplifier is used to drive a tweeter
system.
At this setting, Crossover Frequency
Adjustment Knob (
) provides
adjustment between 400 Hz to 6
kHz. The frequencies below the
crossover point will be attenuated
at 12 dB/octave.