Yamaha CS1D Operating Manual page 484

Input functions
B SLOPE
These buttons select the slope of the high pass filter
from 6 dB, 12 dB, or 18 dB.
C (LOW shelving)
If this button is on, LOW EQ will function as a shelv-
ing filter. The Q knob will disappear.
D Knobs
For each band, these buttons adjust the Q, F (center
frequency), and GAIN (amount of boost/cut).
E
(HIGH shelving)
If this button is on, HIGH EQ will function as a
shelving filter. The Q knob will disappear.
F LPF
If this button is on, HIGH EQ will function as a low
pass filter. The GAIN knob will disappear, and Q will
change to SLOPE.
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