XERXES INSTRUCTION MANUAL
REV 0.7
Page
7
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21
are being controlled. Additionally, the note envelope and keyboard tracking can be changed dynamically
based on velocity and keyboard position.
FREQUENCY
Adjusts the filter cutoff point across the frequency spectrum. The lower the knob
setting, the lower the cutoff point.
RESONANCE
Resonance amplifies a narrow range of frequencies at the filter cutoff point. When
increasing the resonance knob, it intensifies the effect up to about 7, at which point
the filter starts oscillating independently with a feedback frequency that is not related
to the oscillator output. This can produce sound effects when used with a frequency
envelope.
FILTER TYPES
•
Lowpass:
Allows lower frequencies to pass below the filter cutoff point.
Frequencies above the filter cutoff point are being blocked at a rate of
24db/octave.
•
Bandpass 1:
When left LED is on, only a narrow band of frequencies close to the
filter cutoff point are passing the filter. Frequencies above and below the cutoff
are attenuated at a rate of 6dB/octave.
•
Bandpass 2:
When right LED is on, only a narrow band of frequencies close to the
filter cutoff point are passing the filter. Frequencies above and below the cutoff
are attenuated at a rate of 12dB/octave. BP2 filter band is narrower than BP1.
•
High Pass:
Allows higher frequencies to pass above the filter cutoff point.
Frequencies below the filter cutoff point are being blocked at a rate of
12db/octave.
ENVELOPE
Envelope knob adjusts the amount a filter envelope will modify the filter cutoff point
at the beginning of each note. Turning the envelope clockwise from 0 causes the filter
envelope to increase the filter cutoff point, resulting in a brighter attack. Turning it
counter-clockwise from 0 has the opposite effect. The filter envelope decreases the
filter cutoff point, resulting in a more muted attack at the beginning of the note. It is
best to modify the Envelope Amount together with the filter cutoff point to find the
best balance for a desired effect.
KEYBOARD
Keyboard knob allows the filter cutoff to track
the note’s pitch played on the
keyboard. When it is turned clockwise from 0, higher pitches have a higher cutoff
frequency, and lower pitches have lower cutoff. This results in higher notes on the
keyboard having a brighter timbre than lower notes. When it is turned counter-
clockwise from 0, the filter cutoff tracks the keyboard position in reverse
–
lower
notes on the keyboard will have brighter timbre than higher notes.
LFO
Low Frequency Oscillator is used to change various parameters such as pitch, filter, amplifier, pulse
width, and oscillator 2 sync phase with adjustable speed, intensity, and delay. There are two
independent LFOs selected by the A/B switch, and their frequencies can be either independent or
