Linear Arithmetic Synthesis was invented by
Roland in the late
80s. Several
L/A synthesizers were released, starting with the
D-50 in
1987 and ending to the
D-70 in
1990.
From the
D-110 owner's
manual:
"LA synthesis involves a great many technological advances resulting not only in a superior sound quality but also an improved ease of programming."
The
concept?
It is based on the
observation that the
attack transient of a
sound is its most important part with respect to
human perception. Therefore the L/A
synths used a
combination of
sampled attack transients and simple
digital oscillators with only
sawtooth and
pulse waveforms to generate the
sustained part of the sound.
The fact that those two parts were
cross modulated was used to
motivate the term "Linear Arithmetic".
Basically, this was just a
buzzword to make the
Roland synths look more
appealing than the
competitors' products.