E-Mu Classic keys, Operation Manual

Page: 16 / 122

14
INTRO - CONNECTION INSTRUCTIONS
POWER UP!
Before applying power, make sure that
you have received the correct AC adapter
for your part of the world (110V or 220V).
Always connect the AC adapter to the
Classic Keys before plugging it into the
wall. The power switch is located on the
right side of the front panel. Classic Keys
and its MIDI controller may be turned on
in any order. When power is applied, the
liquid crystal display will light, indicating
that the Classic Keys is operating.
ABOUT CLASSIC KEYS
Classic Keys, unlike many synthesizers,
utilizes digital recordings of “real”
instruments for the basis of its sound.
This is similar to a tape recorder except
that in Classic Keys, 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 Classic Keys
ROM (Read Only Memory) chips.
Conceptually, the sampling process is
very simple, as shown in the Basic Sam-
pling 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 from memory,
converted back into voltages, then ampli-
fied 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 Classic Keys, we have left out the
analog to digital converter stage since the
sounds are already sampled for you.