Lfos And Memories - Novation A-Station User Manual

LFOs and Memories

A typical synthesizer will have one or more envelopes. One is
always applied to the amplifier. Additional envlopes are typically
used to modify the filter cut off frequency or change an oscilla-
tors pitch.
LFOs
The electronic building blocks so far described allow a sound to
be synthesized. However, apart from the volume changing
throughout the duration, the sound would be fairly static and
uninteresting.
Most musical instruments produce sounds that vary not just in
volume but also in pitch and timbre. To generate this move-
ment, additional sound modifying blocks are included in a typi-
cal Analogue Synthesizer. These generate low frequency wav-
forms of distinct shapes. They are given the name LFOs ( Low
Frequency Oscillators).
The waveforms generated by the LFO's may be fed to other
parts of the synthesizer to create the desired movements.
A typical waveshape for an LFO would be a Triangle wave.
Imagine this slow moving wave being applied to an Oscillator's
pitch. The result would be that the pitch slowly rises and falls
above and below its original pitch.
This would simulate, for example, a violinist moving a finger up
and down the string of the instrument whilst it is being bowed.
Synthesis Tutorial
This subtle up and down movement of pitch is referred to as
the 'Vibrato' effect.
As well as LFOs being available to modify (or more commonly
known as Modulate) different sections of the synthesizer, addi-
tional Envelopes may also be used.
Clearly the more Oscillators, Filters, Envelopes and LFO's there
are in a Synthesizer, the more powerful it becomes.
Memories
Many years ago large modular machines were produced where
each part of the synthesizer was housed in a separate unit
(block). These blocks could be connected together in any com-
bination by patch leads. Every time a new sound was required
the leads would have to be physically disconnected and recon-
nected.
Modern machines such as the A-Station have all the blocks in
one compact unit and the sound generating or modifying blocks
are arranged in a sensible fashion. Front panel switches and
knobs determine how each block functions and where the
sound modifying blocks such as the LFOs and Envelopes are
routed.
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