9
Modes of Operation
1.
PREAMP
+
BOOST
with
the
dual
buffered
FX
LOOP
2.
PREAMP
+
BOOST
3.
BOOST
with
the
dual
buffered
FX
LOOP
4.
BOOST
only
5.
TUNER
MUTE
‐
this
silences
everything
except
the
signal
to
your
tuner,
which
is
plugged
into
the
back
panel
of
the
APP
‐
1
6.
TRUE
BYPASS
(Hardwire
bypass)
This
also
disconnects
the
TUNER
from
your
guitar’s
signal.
The
guitar’s
signal
is
buffered
and
then
sent
to
the
TUNER
jack
is
only
connected
in
the
IN
mode
and
TUNER
MUTE
mode.
By
switching
the
FX
LOOP
in
and
out,
the
user
can
adjust
any
gain
loss
from
the
effects
in
he
signal
chain
with
the
FX
LOOP
RTN
LEVEL
pot.
Also
when
the
FX
RETURN
jack
is
unplugged,
the
signal
path
is
normalized,
meaning
the
FX
LOOP
RTN
LEVEL
pot
is
out
of
the
path
and
the
path
gain
is
equal
to
1.
The
BOOST
circuit
is
post
MASTER,
so
the
level
of
the
MASTER
is
always
boosted
proportionally
up
to
+16dB
of
additional
gain.
Optimizing Signal Levels
Today’s
pedal
boards
are
heavily
populated
with
all
kinds
of
effects
by
players
seeking
to
sculpt
their
special,
often
unique
tone,
and
10
typically
a
chain
of
a
half
dozen
to
a
dozen
stomp
boxes.
Having
so
many
pedals
usually
results
in
a
loss
of
signal
level
and
integrity,
and
most
often
a
signal
path
far
from
optimized.
The
A/DA
APP
‐
1’s
effects
loop
has
a
low
impedance
buffer
driving
the
effects
loop
and
a
high
impedance
buffer
to
recover
any
losses
in
the
effects
chain.
The
recovery
buffer
won’t
color
your
signal
and
has
an
adjustable
level
to
return
the
same
signal
level
that
drives
the
effects
chain.
Using
the
FX
LOOP
IN/OUT
switch,
you
can
“A
‐
B”
your
effects
individually
or
in
a
chain
to
check
their
signal
levels
and,
using
the
APP
‐
1’s
FX
LOOP
RTN
LVL
(Return
Level)
trimpot,
balance
and
optimize
the
signal
coming
from
your
effects
pedals.
This
will
increase
headroom,
lower
noise
and
provide
seamless
switching
of
your
individual
effects
without
jumps
in
signal
levels.
A
step
‐
by
‐
step
procedure
is
available
online
under
APP
‐
1
Tips
and
Settings.