ARP 2600 - Control Rejection Adjustment for VCA; Gain Adjustments for VCA

114
6.1332 EXPONENTIAL
GAIN ADJUSTMENT:
continued
through
from 6.133.
5.
Raise the
EXPONENTIAL
CONTROL
input
to
the VCA
to
maximum.
*
6.
On the
ADSR
Envelope
Transient Generator,
raise
the SUS-
TAIN
VOLTAGE
control
to maximum.
7.
Holding down
the lowest note
on
the
keyboard,
ADJUST
THE VCA
TRIMMER
LABELLED "EXP'L
GAIN" FOR
MINIMUM
SIGNAL
THROUGH THE
SPEAKERS.
6.14
ADJUSTING THE RING
MODULATOR,
for
positive and
nega-
tive nulling
and
proper
gain.
6.141
NULL
ADJUSTMENTS.
1
.
Set
all controls
to
minimum.
2. Set
VCO-1 to
IKHz.
3.
Advance
to
maximum
the
VCO-1 input
to
the
Ring
Modu-
lator,
the
RING
MOD input to
the
VCA,
and the VCA input
to
the Mixer.
Raise the Speaker Volume controls to max-
imum.
4.
ADJUST
THE
RING
MODULATOR TRIMMERS
LABEL-
LED
"POS NULL" AND
"NEG
NULL
41
ALTERNATELY,
TUNING
FOR
MINIMUM
SIGNAL THROUGH
THE
SPEAKERS.
6.142 GAIN
ADJUSTMENT.
1. Set
all
controls
to
minimum.
2. With patch cords, connect
the KEYBOARD
CONTROL
VOL-
TAGE
output
to the
Ring Modulator left
input, interrupting
the VCO-1
connection
to
that input; connect the VCO-1
SQUARE output
to
the
Ring
Modulator right
input,
inter-
ruptingthe
VCO-2 connection
to
that
input;
and connect
the
RING
MODULATOR
OUTPUT
to VCO-2's unattenua-
ted control input, interrupting
the KBD CV
connection to
that input.
3.
Set
VCO-2 INITIAL
FREQUENCY to about
500Hz.
4.
Set the VCO-1 INITIAL OSCILLATOR
FREQUENCY
con-
trol
to
about 1 KHz and
switch it to its LOW-FREQUENCY
range.