Studio Projects SP828 - Manual (Page 3)

5 4
FR
ONT
P
ANEL
CONTR
OLS
-
INDIVIDU
AL
CHANNEL
CONTR
OLS
6)
Line
select
/
Mic
P
ad
This
switch
selects
between
the
XLR
and
TRS
connectors
on
the
rear
panel.
When
UP
,
the
XLR
connector
is
selected,
when
depressed
the
TRS
jack
is
selected.
The
two
jacks
are
“normalled”
together
in
that
the
XLR
signal
is
available
at
the
TRS
jack
if
nothing
is
plugged
into
the
TRS
jack.
This
allows
the
switch
to
do
double-duty
as
a
Line-select
switch
(if
a
plug
is
inserted
into
the
TRS
jack),
or
as
a
-20dB
P
AD
switch
for
the
XLR
jack
if
nothing
is
plugged
into
the
TRS
Line
jack.
7)
P
olarity
re
v
er
se
This
switch
reverses
the
balanced
connections
to
the
preamp
circuit
and
therefore
reverses
the
polarity
of
the
input
signal.
This
switch
is
sometimes
called
“Phase”,
or
marked
as
“Ø”
on
other
products,
but
the
function
is
the
same.
It
is
used
to
change
the
overall
polarity
of
the
signal.
This
matters
most
when
the
signal
is
being
mixed
with
other
signals.
The
overall
sound
of
the
mixed
signals
may
change
depending
on
the
position
of
the
switch.
T
ry
both
positions
when
mixing
channels
together
(through
the
L/R
mix
controls)
8)
Pr
eamp
Gain
This rotary control varies the circuit gain of the preamp.
The minimum gain of the preamp is approximately 15dB, the maximum is 65dB. By using the
Line/P
AD switch, a wide-range of input signals can be accommodated.
This control should be used in conjunction with the Solo switch and Sig/Peak LED
to properly set the channel gain: adjust the Gain control so that the Sig LED is a strong Green intensity
, occasional Red peaks are OK. By using the Solo
switch (#3), the channel can be monitored on the Level meters (#9) and heard in the headphones. FR
ONT
P
ANEL
CONTR
OLS
-
MASTER
&
MONIT
ORING
CONTR
OLS
9)
Le
v
el
Meter
s
These
meters
allow
the
user
to
monitor
the
main
L/R
mix
output,
or
individual
channels
by
using
the
channel
Solo
switches.
Normally
, the
meters
are
show
-
ing
the
output
level
of
the
L/R
mix
(controlled
by
#1
1).
When
any
channel
Solo
switch
is
pressed,
that
channel’
s
signal
level
is
displayed
on
both
meters
and
the
Pwr/Solo
LED
(#10)
turns
Red
indicating
that
the
meters
are
monitoring
the
Solo
mix
bus.
The
Solo
mix
is
made
up
of
all
channels
that
have
their
Solo
switch
pressed,
so
individual
channels,
or
a
mixture
of
channels
can
be
monitored.
The
meters
have
a
VU-response,
and
will
show
the
average
level
of
the
signal.
The
headphone
system
follows
these
meters,
so
anything
that
shows
on
the
meters
can
be
heard
in
the
phones.
10)
P
o
w
er/Solo
Indica
tor
This
LED
normally
is
Green,
indicating
that
the
unit
is
being
supplied
power
(via
the
rear
AC
power
jack).
The
LED
will
turn
Red
when
any
channel
Solo
switch
is
pressed.
This
lets
the
user
know
that
the
meters
are
now
showing
the
Solo
mix
level
instead
of
the
L/R
mix
output.
11)
L/R
Master
Le
v
el
This rotary control sets the overall level of the L/R mix output to the rear-panel output jacks.
The L/R mix is the sum of all of the channels, controlled by
their individual Mix and Pan controls (#1 and #2). 12)
Headphone
Le
v
el
This
rotary
control
sets
the
overall
level
of
the
headphones.
The
headphones
follow
the
Level
Meters
and
normally
monitor
the
L/R
mix.
If
a
Solo
switch
is
depressed,
the
phones
then
monitor
the
Solo
mix
bus.
13)
Phone
jac
k
This 1/4”
TRS jack is used to connect headphones to the unit.
The phones normally monitor the L/R mix, switching over to the Solo bus when a channel
Solo switch is pressed. Best results are obtained with studio-quality phones with an impedance of 30 to 75 ohms.
sp828 manual.indd 2/22/05, 11:06 AM 6-7