Owner's Manual
Phase
Pressing PHASE inverts the phase of the selected input
to
correct
phase
problems
when using
multiple
microphones,
or
when
incorrect
wiring
polarity
has occurred.
Insert
Activating the
INSERT
switch
[illuminated
when active) breaks the signal path of the channel,
so
that the signal sent
to
the
first
ADC
Input
and the analogue
output
on
the
rear
panel is the signal received at the INSERT
RETURN
connector
[on the
rear
panel)
rather
than the
direct
mic, line
or
instrument
signal. This switch is designed to
allow
the input signal to
be
routed to
other
hardware
for
processing and then back into the
ISA
One
for
digital
conversion. The
POST
INSERT
switch
on
the
front
panel allows the
'return
'
signal level
to
be
viewed
on
the
left-hand
LED
peak
meter
before conversion [see the Metering section
on
the next page
for
details).
HPF
Pressing the HPF switch makes the High Pass
Filter
active
in
the audio path. This
is
useful
for
removing any unwanted bass caused
by
proximity
effect
or
rumble
. The
filter
provides a 75Hz knee frequency
with
18dB/octave
roll-off.
Z
In
(Input Impedance)
Pressing the
Z
In
switch steps
through
each of the
four
transformer
preamp input impedance values,
as
indicated by the
corresponding LEOs.
By
selecting
different
values
for
the impedance of the
ISA
One
transformer
input, the
performance
of both
the
ISA
One
preamp and the microphone connected can
be
tailored
to set the desired level and
frequency
response. The impedance
values are
as
follows
:
Low-
6000,
ISA
110
-1k40,
Med-
2k40,
High-
6k8
0
A guide to setting input impedance is available
in
the Applications section.
Instrument
input impedance
The
Instrument
Z
In
switch toggles between High and Low impedance
settings
for
the
instrument
input. [These settings have the
same effect
on
signal level and
frequency
response
as
outlined
in
the input impedance explanation in the Applications section.) The
impedance values are
as
follows:
Low-
470k0,
High-
2.4MO
Instrument
i/o
(01
and AMP)
The
two
connectors
in
the
Instrument
section
on
the
front
panel, labelled
01
and Amp, are
for
connecting a
guitar
or
bass
directly
and then sending back to an amplifier. The
left
unbalanced/TS connector
[01)
is
therefore
an
input
for
receiving the
direct
guitar
signal,
whilst
the
right
unbalanced/TS connector [Amp)
is
an
output
for
linking
back to a
guitar
amp. The
rear
panel
01
OUT
connector can then feed the
instrument
signal to an
external
recording medium
or
audio
interface
. This
facility
can
be
used even
if a microphone
or
line-level
signal is being recorded
simultaneously
[see the Two-channel Recording Options
for
details).
See
the
Recording
an
Instrument
section
for
more
details about using a
guitar
with
ISA
One
.
Phones
The socket labelled phones
allows
a
pair
of headphones
with
a
TRS
%" Jack
plug to
be
connected to ISA
One. When
in
the default
state [the
CUE
MIX button is not lit), the signal received
in
the headphones is the input
or
inputs connected
to
ISA
One
. This
will
normally
be
simply
a mic, line
or
instrument
signal selected
by
the INPUT
switch. However,
in
a situation
where
an
instrument
and
a mic
or
line are
in
use,
or
a
mic/line
and an
external
signal [connected to the
rear
panel), a
non-adjustable
mix of
all
inputs
will
be
heard. For more
information
on
two-channel
recording and
monitoring
options, see the Applications section.
With the
CUE
MIX
button active, the signal sent to the headphones is the one received at the
CUE
MIX INPUTS
on
the
rear
panel.
See
the next section
for
details.
The Volume dial
to
the
right
can
be
used
to
set the level of the signal
in
the headphones, once the relevant source is selected.
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