ARP 2600 - The Classic Patch and Its Extensions; Basic Signal Path: Oscillator-Filter-Amplifier

46
5.03
A
few
words about
our
procedure
in
this chapter.
We begin
from
the
classic
Oscillator-Filter-Amplifier
patch
without
voltage
con-
trol,
and
build onto it
until
we have
arrived
at the
classic
live-perform-
ance
patch
5.14. Each
significant
addition
to the
patch
is
illustrated
with
at least
a block
diagram;
for the
first
few we also
give a diagram
of the
2600
face
panel,
showing
the
patch
connections.
_
5.031
NOTE
THAT
since
all the
connections
involved
in
what we
have
called
the
"classic"
patch are
prewired
into the
2600,
activating
them
is simpiv a
matter
of
raising,
or
opening,
a
few
attenuators.
This
remains true
for
many
of
the more
complicated
or unusual
patches
that we
deal
with
later
on;
accordingly,
on our block
diagrams
we
indicate
with
the
abbreviation
"p.
cord"
those
connections that
are
not part
of
the
2600
prewired
patch
and
must be
made
by
the
user with
patch cords.
5.031
1 NOTE TOO
that
because
of the
prewired
patch
connections,
it is
important that
all
input
attenuators
not
involved in a particular
patch
must
be COMPLETELY
CLOSED,
i.e. all
the
way down.
Failure
to
observe this
precaution
will
result in
a
great
deal
of con-
fusion.
5.032
The
abbreviations
used in the
block
diagrams
are derived
from
the initials
of the
2600
functions. Thus
"EF"
is
the
envelope follower,
"MP"
the
Microphone
Preamp, and so
on.
Since
there are
three
sep-
arate
voltage
processors
we
refer to them by
their function;
"VPinv"
or
VPlag". To
simplify
the
diagrams
we allow
control
signals to
leave
either
from the right
side or
the
top.
Ring
Modulator
Inputs are
drawn
according to
the
way the
modulator is
functioning
in each
patch.
In
general
signal
paths are
from
left to
right and
control
paths
from
bottom
to
top.
5.04
This
chapter is
designed to be
user
expandable
with
additional
patch diagrams,
block
diagrams,
performance notes,
etc. To
make this
easier, we
have,
as
far as
possible,
restricted the
later
portions of
the
text
to
two
numberedsectionson
each
page. Between any
two pages,
therefore,
another
page
can
be inserted
and numbered in
logical sub-
ordination
to
the
other
pages. This
system
is indefinitely
expandable.
From
time to time,
as
2600
users
feed back to us
the
results of
their
experience,
we will
send
out
patch
and use notes to
be inserted
in
their
proper
places in
this
chapter.