ARP 2600 - Clock out

42
Because
of
its effect
on
audio
signals
the
lag processor
can
dou-
ble
as
a low-pass filter
with maximum
F
c
of 1
600Hz.
Minimum F
c
is
subsonic
at
1.6Hz.
When it
is
used in
this
fashion,
the
cutoff
slope
is
—
6Db/Octave
above
F
c
.
The
input
impedance of the
voltage inverters
is SOKohms
min-
imum and of the lag
processor
1
Kohm
minimum
above
1
.6KHz.
4.6 The PERIPHERAL
EQUIPMENT
includes
the
MICROPHONE
PREAMP, the ELECTRONIC
SWITCH, the INTERNAL
CLOCK,
the
MIXER
and
PAN POT,
and the
REVERBERATION UNIT.
All of
these
are extremely simple functions
with few
or
no
controls
except
input
or output
attenuators.
4.61 The
MICROPHONE PREAMP
accepts
any low-to-medium
imped-
ance input.
A
rotary
attenuator controls
the
level of
the input,
and
a
three-position
slide
switch
selects one of three operating ranges;
20,
40,
or
60Db gain.
The
preamp
is
useful not
only
with microphone signals,
but
also with direct inputs
from
electric
instruments and for some pur-
poses even with
signals internally generated
by
the
2600 itself.
Work-
ing with
a signal of
unknown strength, it is best
to
begin with
the
low-
est gain
in finding the
best
operating range
for
the
preamp.
4.62 The
ELECTRONIC SWITCH is bidirectional.
That
is, it
will
either
switch
a
single
input alternately
to its
two outputs,
or it
will
accept
two
inputs
and
switch
them
alternately to
one
output.
The
switch
is useful both for
audio
and
control signals.
4.621 INTERNAL
CLOCK:
this
is simply
a
square-wave oscillator
serving
a particular
purpose. Its output
is
permanently
connected to
the
electronic switch;
it is prewired to
the sample command
input of
the
Sample and Hold
circuit and
to the Envelope Generators external
gate
input.
The
frequency
of
the
INTERNAL CLOCK is
governed
by
the
RATE control
and
covers a
range of
approximately
.2Hz
to 100Hz.
The
output from the clock
is
available
independently
at
the
INT
CLOCK
OUT
jack.
4.63
The
general
purpose MIXER accepts
two inputs through atten-
uators and feeds
their
sum
to
the
panpot. Note the
two
jacks just
above
the attenuators: insertion
of
a
patch
cord
to one
of these
jacks
disconnects the
attenuator output
from
the
mixer
input. These
are
output jacks
and
make it
possible to
use
the
mixer
input attenuators