Operation Manual

28 Parameters
located at the center of each module for a wide range of possibilities. The effect list includes a
Delay, Distortion, Chorus, Flanger, Phaser, Wah Wah, Auto Wah and a Notch filter.
The Multi-Effects module is also visible from the Play view just below the utility section. This
allows one to see rapidly which effects are selected for a given sound, turn the effects on or off and
rapidly adjust the amount of each effect. The Compressor, Equalizer and Reverb can also be
adjusted from this view.
5.3.1 EQ
The EQ module provides equalization over the low, mid, and high frequency bands. It is composed
of a low shelf filter, two peak filters, and a high shelf filter in series, labelled LF, LMF, HMF, and
HF respectively.
The functioning of the low shelf
filter is depicted in Figure 11. The
filter applies a gain factor to low fre-
quency components located below a
cutoff frequency while leaving those above unchanged. The cutoff frequency of this filter is ad-
justed using the Freq knob and can vary between 40 and 400 Hz. The Gain knob is used to adjust
the gain factor applied to the signal in a ±15dB range. In its center position there is no attenuation
(0 dB). Turning it clockwise boosts the amplitude of low frequencies while turning it anti-clockwise
reduces it.
The high frequency content of the signal is controlled with a high shelf filter that works in
the opposite manner as the low shelf filter as illustrated in Figure 11. The filter applies a gain
factor to components located above a cutoff frequency while leaving those below unchanged. The
cutoff frequency of this filter, located above 1 kHz, is adjusted with the help of the Freq knob
while the gain factor applied to the signal, in a ±15dB range, is adjusted using Gain knob. In its
center position there is no attenuation (0 dB). Turning it clockwise boosts the amplitude of high
frequencies while turning it anti-clockwise reduces it.
Amplitude (dB)
0dB
Freq Frequency (Hz)
Amplitude (dB)
0dB
Frequency (Hz)Freq
Gain = −30 dB
Gain = 10 dB
Gain = 20 dB
Gain = 30 dB Gain = 30 dB
Gain = 20 dB
Gain = 10 dB
Gain = −30 dB
Figure 11: Low and high shelf filters.