ALM-011 - ‘Akemie’s Castle’
Background & Caveats
Frequency Modulation (FM) synthesis is an audio synthesis technique where
waveforms modulate each other at audio frequencies to produce a wide array of both
harmonic and in harmonic sounds. These modulation waveforms are referred to as
‘operators’. The combination and routing of a number of operators to produce a sound
is referred to as an ‘algorithm'.
FM synthesis was made hugely popular is the mid 1980’s with the launch of the
Yamaha DX7 synthesiser. Yamaha implemented this through the use of custom digital
FM synthesis chips which were used not just across their synthesiser range but also in
gaming machines and home computers. For more information visit:
en.wikipedia.org/wiki/Frequency_modulation_synthesis
Akemie’s Castle uses a vintage ‘new old stock’ Yamaha YMF262 (aka OPL3) chip as
a sound source and exposes all operator parameters to both voltage and direct control.
It is able to produce multiple voice 2 or 4 operator FM based sounds from 6 algorithms
and 7 selectable waveforms. This is very similar in audio capability to the Yamaha
DX100, DX21 or TX81Z synthesisers.
Using an original chip gives a very authentic and special sound that has never been
put under direct modular control before. This allows easy, fun and painless exploration
of FM sounds that was not really possible with the heavy, menu bashing small screen
style of programming the FM synths of the 80s.
However, using an original chip imposes some limitations, some of which become
more apparent with such direct control. Expect some ‘stepiness’ and potential low level
clicks when changing certain parameters. It is only possible to modulate parameters
up to low audio rates. The chip will alias and even distort if pushed hard enough in
certain settings - care should be taken. One can quickly go from rich tonal bliss to
crushing noise. It is a beast, but one that can be tamed. Embrace and enjoy these
limitations.
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