About The Proteus - E-Mu Proteus Operation Manual

24 About Proteus
PROTEUS
about
Proteus, unlike most synthesizers, utilizes digital recordings of real
instruments for the basis of its sound. This is similar to a tape recorder
except that in the Proteus, the sounds are permanently recorded on
digital memory chips.
To perform this modern miracle, sounds and instrument waveforms are
first sampled into the Emulator III, our top of the line, 16 bit stereo digital
sampler. After the sounds and waveforms have been truncated, looped
and processed, they are "masked" into the Proteus ROM (Read Only
Memory) chips.
Conceptually, the sampling process is very simple, as shown in the Basic
Sampling System diagram. As a sound wave strikes the diaphragm of a
microphone, a corresponding voltage is generated. To sample the sound,
the voltage level is repeatedly measured at a very high rate and the
voltage measurements are stored in memory. To play the sound back, the
numbers are read back out of memory, converted back into voltages, then
amplified and fed to a speaker which converts the voltage back into sound
waves. Of course, playing back 32 channels at different pitches tends to
complicate matters, but this is basically how it works. In Proteus, we have
left out the Analog/Digital converter stage since the sounds are already
sampled for you.
Basic Sampling System
Analog/Digital
Converter
1011001 1011001
Memory Digital/Analog
Converter
10100101001
01010010100
1011001
10101010100
10101001010
3V
0V
-3V
1V 3V -2V -1V 3V -1V -2V
Proteus operation manual
Amplifier