Envelopes 1&2 Section - Novation Bass Station Rack Owner's Manual

HOW THE CONTROLS WORK
Filter Section - Continued
Resonance - Rotary
This knob allows you to boost or emphasise the frequencies around the Cut-off fre-
quency (set by Frequency knob above). For this reason on some synths this control is
known as Emphasis. At the far left there is no boosting of the cut-off frequency, but as
you turn to the right this frequency will be boosted until at the far left it goes in to oscil-
lation producing a new pitched element (similar to feedback on an electric guitar). If
ever the BassStation produces a high whistling sound. the chances are this knob is
too far to the right. Unless you want this self-oscillating effect, keep the resonance
control away from the extreme right setting. Increasing the Resonance is very good for
bringing out modulation (movement or change) in the filter cut-off frequency, such as
in Acid basslines and other very up-front sounds. Keep the resonance to a minimum if
you want more subtle less striking sounds.
Cut-Off - Switch
This switch allows you to change how drastically the frequencies above the cut-off
point are removed from the sound. In the 12dB position, the cut-off slope is less steep
so the higher frequencies are not attenuated (reduced in volume) as much as they are
in the 24dB position. This makes the resulting filtering in the 12dB position more sub-
tle than the 24dB, which you should select if you want the cut-off to be more obvious.
Mod Source - Switch
This switch selects the amount of variation in the filter cut-off frequency set by the
Modulation knob above using either the LFO and/or Envelope 2. When LFO is select-
ed, the filter cut-off will be moved around the starting point set by the Frequency knob
at a rate set by the Speed knob in the LFO Section. The amount of movement is set
by the Modulation knob above. When Env 2 is selected, the filter cut-off will be moved
away from and back to the starting point set by the Frequency knob. If the Modulation
knob is set to a negative amount, the Attack of Envelope 2 will close the filter and the
Decay/Release will re-open it back to the starting point. If the amount is positive, the
Attack will open the filter further and the Decay/Release will close it back to its starting
point. Using positive Modulation from Env 2 will emphasize the attack of the note
(especially if the Resonance is turned up). whereas LFO modulation will provide a
tremolo effect.
External Audio Input To The Filter
This feature can be used to process an external audio signal through the BassStation
Rack's Filter and Envelope sections. Connect the audio output of the device you wish
to process to the 'Filter Input' socket, and the MIDI Out to the MIDI In on the
BassStation Rack's rear panel. The Envelopes will only open when MIDI data or a vin-
tage synth's Gate trigger pulse are received, so to process a signal from an instrument
without this facility you must use a separate MIDI device (sequencer) or Gate pulse to
open the Envelopes when you want the sound to occur. Try experimenting with the
'MIX' knob to create a blend of the external signal and the BassStation Rack's own
oscillators. See page 3 for connection details.
Envelopes (1 &2) Section
The envelopes are used to shape the sound over time.
Envelope 1 is hard-wired' to amplitude or volume. It is
used to decide how quickly the sound starts when you
hit a note and how it sustains or dies away. Envelope 2
can be used to control Pulse Width, Filter frequency or
Pitch changes depending on the settings of the 'PWM
Source' switch in the 'Osc 1 - 2 Mod/Sync' section and
the 'Filter Mod' switch in the 'Filter' section. Of
course, if neither of these is switched to Env 2, you
will hear no change when you alter the settings of
Envelope 2. Switch one or the other to Env 2 to hear
the changes you are making.
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