User Manual

CHAPTER 23. LIVE INSTRUMENT REFERENCE 395
23.8.5 Filter Section
Operator's Filter Section.
Operator's lters can be very useful for modifying the sonically rich timbres created by the
oscillators. And, since the oscillators also provide you with the classic waveforms of analog
synthesizers, you can very easily build a subtractive synthesizer with them.
The lter section offers 14 different lter types including multiple varieties of lowpass,
bandpass, highpass and notch lters. The 12 and 24 dB modes refer to the amount of
attenuation. The 24 dB modes attenuate the ltered frequencies to a much greater degree
than the 12 dB types, and are commonly used in the creation of bass patches. The SVF
(state-variable lter) modes are 12 dB types but with a different architecture. They will
self-oscillate as their resonance is increased. The Ladder modes have 24 dB slopes and are
based on the lters found in some classic analog synthesizers.
The Envelope and Filter buttons in the lter section's display area toggle between showing
the lter envelope and its frequency response. Filter cutoff frequency and resonance can
be adjusted in the shell or by dragging the lter response curve in the display area. Filter
frequency can also be modulated by note velocity, note pitch, the LFO and the lter enve-
lope. The Freq<Vel, Freq<Key and Envelope controls in the lter's display set these three
functions, respectively.
Tip: The (PC) /
Ctrl
(Mac) context menu on the Frequency knob contains an entry
called Play by Key. This automatically congures the lter for optimal key tracking by
setting Freq<Key to 100% and setting the cutoff to 466 Hz.
The lter's signal can be routed through a waveshaper, whose curve type can be selected
via the Shaper chooser. The Drive slider boosts or attenuates the signal level being sent to
the waveshaper, while the overall balance between the dry and processed signals can be