Eventide Ultra-Harmonizer H3000 - Signal Processing

INTRODUCTION
The
purpose
о!
this
service
manual
is
to
provide
technical
information
on
the
H3000
Uitra-Harmonizer.
It
is
meant
as
a
starting
point
in
trouble
shooting
any
problems
encountered
with
the
H3000
in
the
field
and
to
provide
some
insight
into
its
capabilities.
Some
familiarity
with
its
operation
is
necessary
so
refer
to
the
H3000
Instruction
Manual
for
help
with
basics.
The
H3000
is
a
software-based,
digital
audio,
signal
processor
which
uses
electronically
balanced,
stereo
inputs
and
outputs
to
produce
a
variety
of
audio
effects.
These
range
from
simple
time
delay
to
pitch
shifting.
In
addition
to
its
audio
capabilities
the
H3000
includes
a
sophisticated
MIDI
implementation
which
allows
it
to
communicate
with
other
MID!
devices.
SIGNAL PROCESSING ARCHITECTURE
The
Н3000
is
a
general
purpose,
software
based
signal
processing
device.
This
allows
a
quicker
design
cycle
and
flexible
signal
processing
algorithms.
The
primary
goal
is
à
stereo
pitch
shifter,
so
the
architecture
is
based
on
the
computational
needs
of
pitch
shifting.
In
addition
to
raw
computing
power
the
H3000
is
a
flexible,
software
based
design,
the
signal
processors
are
RAM
based,
so
that
their
programs
are
downloaded
by
the
host
microprocessor.
Also,
the
host
easily
changes
signal
processing
parameters
while
the
signal
processing
programs
are
executing.
Finally,
the
signal
processors
address
a
large
block
of
memory
in
order
to
implement
long
audio
delay
lines.
A Shared Resource Multi-Processor
The
signal
processing
elements
(for
convenience
called
"PELs")
share
most
of
the
available
resources,
including
the
data
converters,
the
interface
to
the
host
processor
and,
especially,
the
large
block
of
memory
for
delay
lines.
The
architecture
is
built
around
a
single
"global"
bus.
Attached
to
this
bus
are
ail
of
the
PELs,
the
delay
memory,
the
A/D
and
D/A
converters,
and
the
host
interface.
The
bus
is
active
only
when
data
is
to
be
transferred
between
devices
on
the
bus.
Each
processor
has
its
own
local
memory,
allowing
the
bus
to
remain
free
during
поп-/О
processing.
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