ARP 2600 - Voltage Controlled Oscillators (VCOs); VCO Operating Ranges and Control Inputs; VCO-1 Output Waveforms (Sawtooth, Square)

28
4.11
The
three VOLTAGE
CONTROLLED OSCILLATORS
share
some common
characteristics.
1
.
Each VCO has
two
operating
ranges
selected
by
a
switch
in
its lower
left
corner. The
range labelled
AUDIO
is
from
10Hz
to 10KHz,and the
range
labelled LF
(for
LOW
FREQUENCY)
is
from
.03Hz,
or one
cycle approximately every 30 seconds,
to
30Hz.
2. Within either
operating range,
the
frequency
of
each
VCO
is
manually
controlled
by two
sliders.
One is labelled
INITIAL
OSCILLATOR
FREQUENCY and
covers
about
ten
octaves.
The other
is
labelled
FINE
TUNE
and covers
a
little
less
than
half
an
octave.
3.
Each
VCO accepts
up
to four
frequency-control
inputs
(labelled FM
INPUTS). Three of
these
are
governed
by log-
arithmic
input
attenuators; one
is
unattenuated and
is pre-
wired
in
each
VCO to
the
KEYBOARD CONTROL VOL-
TAGE.
4.
Use
of
any VCO in
its
LF range
automatically disconnects
it
from
the
KEYBOARD
CONTROL VOLTAGE.
If
it
is desired
to
reinstate
this connection
during LF operation this
must
be
done by
patch-cord.
5. The
sensitivity of
each VCO
to
control voltages is
1V/Octave.
The
impedance of
the control inputs is
50Kbhm
minimum.
The
signal output impedance
is IKohm.
4.1
1 1
The first
oscillator,
VCO-1
,
generates
SAWTOOTH and SQUARE
waves at
two inde-
pendent
outputs. Peak amplitude of
each signal
M«V