Chapter 3 - Dpm V3 Programming; History And Background; How The Dpm V3 Generates Sound; Software Emulation Of An Analog Synthesizer - Peavey DPM V3 Owner's Manual

Chapter 3 — DPM V3 Programming
3.1 HISTORY AND BACKGROUND
Synthesizers used to consist of various hardware modules, some of which generated
signals, and some of which modified those signals. Much of audio involves elements
that make sounds and elements that modify sounds (such as a guitar and amplifier).
Early synthesizers were highly experimental devices. To be as general-purpose as
possible, patch cords connected the inputs and outputs of the various signal
generating and processing modules (which is why particular synth sounds were called
patches). Changing a patch involved manually repositioning patch cords and adjusting
knobs and switches; if you wanted to recreate a patch at some later time, it was
necessary to write down all the patch settings on paper. Even then, due to the
vagaries of analog electronics, trying,to recreate a patch often didn't produce the
same results. £
Over the years, certain combinations of modules seemed to work better than others,
and since patch cords were troublesome to deal with, eventually these modules were
wired together in a "normalized" configuration. Synthesizers such as the Minimoog,
Prophet-5, and others eliminated the need for patch cords by containing a normalized
collection of sound modules.
3.1a How the DPM V3 Generates Sound
The DPM V3 uses the same approach to sound generation as Peavey's DPM 3, the
first popularly-priced keyboard synthesizer to use general-purpose Digital Signal Pro-
cessing (DSP) chips for sound generation. These chips are essentially computers
designed to generate and/or process digital audio signals, and can even do special ef-
fects like chorusing and reverb. The DPM V3's three DSP chips are in turn controlled
by a central computer. Because the function of these chips depends on the software
controlling them, it is possible to upgrade the DPM V3 with entirely new methods of
sound generation by writing new software.
3.1b Software Emulation of an Analog Synthesizer
In the current generation of DPM V3 software, the DSP chips have been programmed
to emulate a traditional analog synthesizer, but with digital sound-generating
capabilities. Each synthesizer "module" is a page on the display, and each "knob" or
"switch" is a parameter on the page. You can step through different parameters using
a combination of buttons and a data entry knob. All "patching" is done via software,
eliminating the need for patch cords; you simply specify which inputs should receive
which outputs in those cases where connections are not normalized.
3.1