2009

Table Of Contents
An alternative solution was the use of general-purpose processors made by third-party
computer processor manufacturers. These processors, especially designed for multiplication
and accumulation operations—common in audio processing tasks—are called digital
signal processors (DSPs). Peavey’s DPM-3, released in 1990, was the first commercially
available synthesizer completely based on standard DSPs. The instrument was 16-note
polyphonic and based mainly on three Motorola 56001 DSPs. It featured an integrated
sequencer and sample-based subtractive synthesis, with factory presets and user-definable
samples.
Another solution was to design synthesizers as a computer peripheral, rather than as a
standalone unit. The growing popularity of personal computers from the early 1980s
made this option commercially viable. Passport Soundchaser and the Syntauri
alphaSyntauri were the first examples of this concept. Both systems consisted of a
processor card with a standard musical keyboard attached to it. The processor card was
inserted into an Apple II computer. The synthesizers were programmed via the Apple
keyboard and monitor. They were polyphonic, had programmable waveforms, envelopes,
and sequencers. Todays sound cards, introduced in countless numbers since 1989, follow
this concept.
Exploiting the ever-increasing processing power of today’s computers, the next
evolutionary step for the synthesizer is the software synthesizer, which runs as an
application on a host computer.
The sound card (or built-in audio hardware) is needed these days only for audio input
and output. The actual process of sound generation, effects processing, recording, and
sequencing is performed by your computers CPU—using the Logic Studio software and
instrument collection.
561Appendix Synthesizer Basics