ARP 2600 - Ring Modulator Adjustments; Null Adjustments for Ring Modulator

115
5.
Set
the Ring
Modulator
coupling
to
DC.
6.
Advance to
maximum:
both
Ring
Modulator
inputs, the
Filter
input
from VCO-2,
the Filter
frequency, and the Mix-
er input from
the
Filter.
Raise the
Speaker Volume
controls
to a
comfortable level.
7.
Holding
down the
lowest F-sharp
on
the
keyboard,
ADJUST
THE
RING MODULATOR
"GAIN"
TRIMMER UNTIL
THE
TONE FROM
VCO-2
IS SHIFTING
EXACTLY
ONE
OCTAVE.
6.15
This
concludes
the calibration
and
alignment
procedure.
6.2
MAINTENANCE.
Most of
what you
should
be
concerned with
here is
merely preventive: do
not
expose
your
Model 2600 to
extreme
heat or cold, don't
leave
it
out
in
the
rain, or
set
it
down in the
mid-
die
of
busy
intersections.
If
after extended use the
exposed
surfaces of the 2600
begin
to
get
dirty,
they may
be cleaned
with a
soft damp
cloth.
If
you-
decide to wax
it,
take
great
care
to
prevent the wax from
entering
the
control
slider slots
where
it could
build up
and
eventually affect
the
sliders'
contact
surfaces.
Take care
in general
that
wax does not
build
up
in any
crevices,
or
between
the keys
of
the
3604
controller.
Don't
try
to take the 2600
apart to
get inside;
doing so
will
void
your
warranty. All possible
interconnections
can be
made
exter-
nally; we have
designed
the 2600
specifically
so
that
all user-adjustable
trimmers
are available
without
disassembly.
DO
NOT ATTEMPT TO ADJ
UST THE
FIXED
"PRESET"
TONE
INTERVAL
TRIMMER
ON THE 3604
KEYBOARD.
Unlike
the
other exposed
trimmers,
it
cannot be
precisely trimmed
without
external test
equipment and is
factory-preset
for EXACTLY
a
+4V
interval across
the keyboard span.
This interval
in fact serves
as a
ref-
erence
for
much
of the alignment
procedures
in
6.1 ,
and if
it
is
dis-.
turbed
the
alignment
procedures
are worthless.
6.21
CLEANING
THE KEYBOARD
CONTACTS.
Occasionally
the keyboard
contacts
will
become obstructed
by
dust or dirt,
causing the keyboard
control
voltage to become
un-
steady or
intermittent. They
may
be
cleaned
with q-tips and
alcohol
or tape head
cleaner.