13
1’s
OUTPUT
jack.
If
you
want
to
just
drive
the
amplifier,
you
can
do
so
by
switching
the
PREAMP
+
BOOST
switch
to
the
right
and
the
FX
LOOP
switch
to
the
right,
so
the
only
function
of
the
APP
‐
1
is
the
BOOST.
If
you
want
BOOST
and
the
FX
LOOP
engaged,
set
the
FX
LOOP
switch
to
the
left
and
the
PREAMP
+
BOOST
switch
to
the
right
position.
Effects Loop (FX LOOP) Setup
The
effects
loop
is
a
dual
‐
buffered
loop
so
the
signal
from
the
APP
‐
1
is
low
impedance
capable
of
driving
many
effects
boxes
without
any
change
in
signal
integrity.
The
return
signal
from
your
effects
chain
is
also
buffered
with
a
high
impedance
buffer
that
has
a
gain
control
so
you
can
balance
or
bring
back
any
signal
loss
from
your
effects
chain.
To
help
setup
the
FX
LOOP
properly,
the
APP
‐
1
has
switch
labeled
“FX
LOOP”
to
switch
to
switch
in
or
bypass
the
signal
through
your
effects.
This
is
used
to
trim
the
level
with
the
“FX
LOOP
RTN
LVL”
control
in
order
to
optimize
your
signal
path
and
to
balance
the
levels
of
the
preamp
and
your
effects
boxes.
Tuner Out and Tuning
The
TUNER
jack
on
the
rear
panel
of
the
APP
‐
1
allows
you
to
connect
your
Tuner
through
an
isolation
buffer
so
that
it
never
colors
or
loads
down
your
guitar
signal.
It
also
allows
you
to
tune
at
any
time,
and
14
by
switching
the
TRUE
BYPASS
switch
to
the
far
right,
you
can
tune
while
your
stage
and
house
sound
is
muted.