Russco Studio/Master 505S User manual
www.SteamPoweredRadio.Com
STUDIO/MASTER 505S
5
CHANNEL
STEREO
BROADCAST
AUDIO
MIXER
WARRAN
TY
All
Russco
products
are warranted
aga
i
nst
defect
s in
workmanship
and
materials
for
a
pe
r
iod
of
one year
from
the date
of
del
ivery.
We
will
repair
or
replace
products
whi
ch
prove
to
be
defect
i
ve
dur
i
ng
the war-
ranty
period
provided
they
are
returned
to
Russco.
Warranty subject
to
cancellation if in the
opinion
of
Russco the
product
has been
either
unduly
tampered
with
or
modified
so
as
to
cause failure
beyond
our
control.
No
other
warranty
is
expressed or implied.
We
are
not
liable
for
conseque
nt
i
al
damages.
RUSSCO
ELECTRONICS MFG., INC.
5690
East Sh
ields
Fresno,
Californi
a 93727
www.SteamPoweredRadio.Com
Studio/Master
505S/505SR
Table
of
Contents
TABLE
OF
CONTENTS
Section
Page
I.
GENERAL
I
NFORMATION
.......
..
.....
.
.....
. .
1-1
1-1.
Description
.
..
.
....................
1-1
1-9.
Specifications
. .
......
..
...
..
....
. .
1-2
1-11.
Accessories
.
.....
..
....
..
.
....
....
.1- 2
II.
INSTALLATION
...
..
.....
..
..
..............
.
2-1
2-1.
Unpacking
......................
..
..
2-1
2-4.
Mounting
...........................
2-1
2-8.
Input
Assignments
. . . .
..............
2-1
2-12.
Input
Connections
. . . .
........
..
....
2-2
2-
19.
Output
Connections
.................
2-3
2-
32.
Power
Connection
..
.
...............
.
2-4
2-34.
Ground
Connection
................
. .
2-4
.III.
CALIBRATION
...
.
............
.
...
. .
...
.....
3-1
3-1.
Jumper
Settings
....................
3-1
3-11.
Level
Settings
...
. .
....
...
.........
3-2
IV.
SPECIAL
MODIFICATIONS
..........
·
.......
.
..
4-1
4-1.
High
Level
Switch
Termination
.....
.
4-1
4-4.
Remote
Start
of
Equipment
.....
.
....
4-1
4-10.
Remote
Control
of
Channel
1- 4
......
4-2
V.
OPERATING
INSTRUCTIONS
...................
5-1
5-1.
General
. .
..........................
5-1
5-5.
Controls
and
Indicators
...
.........
5-1
5-19.
Operations
Method
...............
.
..
5-3
VI.
THEORY
OF
OPERATION
........
.
..
...........
6-1
6-1.
General
.........
...
.......
.......
..
6-1
6-3.
Block
Diagram
....
.
....
.......
......
6-1
6-11.
Input
Pads
......................
.
..
6-3
6-13.
Integrated
Circuits
................
6- 3
6-17.
Equalization
.......................
6-3
6-
19.
Booster
Amplifier
........
.
........
.
6-3
6-21.
Cue
Amplifier
......................
6-4
6-23.
Headphone
Amplifier
..........
.
.....
6- 4
6-25.
Power
Supply
.......................
6-4
6-28.
Monitor
Buffer
.......
.
........
.
....
6-4
6-
30.
FET
Switches
................
.
......
6-4
VII.
MAINTENANCE
..............................
7-1
7-1.
General
............................
7- 1
7-3
.
Dismantling
for
Service
Access
.....
7-1
7-10.
Changing
Pots
.....
.
...............
.
7-2
7-
12.
General
Repair
...................
..
7-2
7-17.
Changing
Integrated
Circuits
.......
7- 3
7-19.
Returning
for
Service
..............
7-3
7-21.
Serial
Number
......................
7-4
VIII
.
SCHEMATICS
.........
.
.....................
8-1
8-1
.
Introduction
.......................
8-1
IX.
REPLACEMENT
PARTS
.................
.
..
.
...
9-1
9-1
.
Introduction
...................
.
...
9-1
i
190-
011
www.SteamPoweredRadio.Com
Studio/Master
505S/505SR
Table
of
Contents
LIST
OF
TABLES
Number
Page
1-1
Specifications
........
.
..................
..
.
..
...........
1-3
1-2
General
Information
...................
..
................
1-4
2-1
Factory
Settings
of
Jumper
Options
.
....................
.
2-3
3-1
Identification
&
Color
Coding
of
Jumpers
................
3-3
7-1
Trouble
Chart.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7-
5
9-1
Replacement
Parts.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9-2
LIST
OF
ILLUSTRATIO
NS
Number
Page
1-1
Studio/Master
505S/505SR
Audio
Mixer/Console
....
......
..
.
1-0
2-1
Typical
Input
Configuration,
Using
Factory
Se
ttings
......
2-2
2- 2
Typical
Output
Connections
...........
..
..................
2
-5
3-1
General
Parts
Locations.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-4
3-2
Main
Board
Pot
&
Jumper
Locations
. .
......................
3- 5
3-3
Cue,
Mute
&
Stereo/Mono
Jumper
Locations
.................
3-6
3-4
Preamp
Board
Jumpers
...
.
......
...
.
.......................
3-7
5-1
Front
Panel
Controls
..........................
.
......
....
5-2
6-1
Block
Diagram
.......................
...
..................
6-2
7-1
Signal
Tracing
Setup
...
...
...............................
7-4
8-1
Pr
eamp
P.C.
Board
.
...................
.
......
..
...........
8-2
8-2
Main
P.
C.
Boa
rd.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8-3
8-3
Pot
P.C.
Board
........
.
..................................
8-3
8-4
Schematic..
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8-4
Number
9-9
9-10
9-11
190-011
ADDENDUM
Page
Level
Diagram
..................
. . .
...
....
...
...
...
.......
9
-9
Cartridge
Response
.......................................
9-10
Hi-Gain
Modification
.................
..
...
.
..............
9-11
ii
www.SteamPoweredRadio.Com
Studio/Master
SOSS/505
SR
Section
I
SECTION
I
GENERAL
INFORMATION
1-1
. DESCRIPTION
109-011
1-2
.
The
Russco
Studio/Master
SOSS
Audio/Mixer
Console
is
a
professional
stereo
audio
mixer
designed
for
broadcast
studio
applications
where
five
mixing
channels
provides
adequate
flexibility.
The
SOS
features
built-in
preamps
on
mixers
1
thru
4
and
five
balanced
high
level
inputs
on
mixer
5.
Also
featured
is
cue
on
all
channels,
light
emitting
diode
(LED)
indicators,
headphone
amp,
on-the-air
warning
light
relay
driver
and
field-effect
transistor
(FET)
muting
for
the
monitor
output
.
1-3
. Cue
and
mute
features
can
be
deleted
from
any
channel
by
removing
jumpers
on
the
mixer
printed
circuit
board.
The
preamps
can
be
modified
for
RIAA
phono
,
microphone
or
hi
level
unbalanced
input
by
moving
jumpers
on
the
pc
board.
1-4.
The
SOSS
comes
with
a
finished
cover
for
desk
top
installation.
The
rack
mount
version
(model
SOSSR)
is
supplied
without
the
cover
.
It
mounts
in
an
EIA
standard
19
11
rack
taking
5
1/4"
of
vertical
space
.
1-5
.
The
SOSS
uses
integrated
circuit
ampli
f
iers
through
-
out
,
with
power
transistors
to
drive
the
cue
and
headphone
outputs.
The
output
line
impedance
is
600
ohms,
balanced
.
The
VU
meter
features
true
VU
ballistics.
1-6
.
The
monitor
output
is
driven
by
a
low
impedance
output
line
amplifier.
The
monitor
amplifier
may
be
located
away
from
the
console.
1-7
.
Audio
switching
on
channels
1-4
is
done
with
solid
state
field-effect
transistors
(FET) .
These
switches
can
be
remote
controlled
by
DC
switching.
1-8
. Any
monaural
source
may
be
split
to
feed
both
outputs
by
movin
g a
jumper
on
the
pot
.
P.C.
board.
This
causes
no
additional
loading
on
the
source.
1-1
www.SteamPoweredRadio.Com
Studio/Master
505S/SOSSR
Section
I
1-2
1-9.
SPECIFICATIONS
1-10
.
Table
1
-1
lists
the
specifications
for
the
Studio/
Master
505S.
General
information
is
listed
in
Table
1-2.
1-11.ACCESSORIES
1-12.
Many
accessories
for
the
Studio/Master
505S
are
available
from
Russco
Electronics.
Included
are
monitor
speakers
and
headphones,
microphones
and
stands,
remote
start
relays
and
headphone
jack
boxes
.
1-13.
Russco
studio
turntables
are
available
finished
to
match
the
Studio/Master
505S .
109-011
www.SteamPoweredRadio.Com
Studio/Master
505S/SOSSR
Section
I
Table
1-1.
Specifications
Inputs:
9
Total
Stereo
Channels
1- 4
(Preamps,
Unbalanced
Stereo)
Sensitivity.,.,.
Max
Input
Impedance
Hi
Level
-lOdBm
+14dBm
47K
Microphone
70
'1'
l.OOmv
13mv
47K
Channel
5
(Balanced,5
Stereo
Inputs,
Switched)
,\-Sensitivity:
Max
Input:
Impedance:
Outputs:
- l
OdBm
+18dBm
600
ohms
Monitor:
(External
Package,
Opt
i
onal)
lOmv
lOOmv
47K
Power:
25
Watts
Average
p
er
Channel
(14.
14
volts
RMS
across
8 ohm
load
at
lKHz)
Impedance:
8 ohms
Total
Harmonic
Distortion:
Less
than
1%
at
full
rated
output
Program:
(Stereo)
Level:
+4
or
+8dBm,
for
OVU,
+17dBrn maximum
Impedance:
600
ohms
Frequency
Response:
20
to
15
KHz,
+
ldB
Total
Harmonic
Distortion:
Less
than
0.5%
at
lKHz, +8dBrn
out.
Noise:
Greater
than
60db
below
+4dBm
output
referenced
to
-50dBm
input.
Headphones:
(Stereo)
Level:
OdBm
Impedance:
Hi
down
to
8 ohms
Cue: (Mono,
both
channe
l s
mixed)
Power:
1
watt
average
Speaker!
8 ohms, 3
inch
On-Air
Light
(Relay
Driver)
Voltage:
-24
VDC
Current:
40ma
(600
ohm
coil)
*Mixer
Pot
at
1:30
o '
clock
position,
OVU
out.
**Referenced
to
low
impedance
microphone
source
,~-Jo'l'At lKHz.
109-011
1-3
www.SteamPoweredRadio.Com
Studio/Master
505S/505SR
Section
I
1
-4
Table
1-
2.
General
Informat
i
on
Controls:
*Input
mixing
- 5
each,
Stereo
Ganged,
with
Cue;
*Monitor
level
- 1
each,
Stereo
Ganged,
with
power
switch,
on
front
panel.
Master
Level
(2)
}
Gue
level
Trim
pot
on
main
P.C.
Board
Headphone
level(2)
10
',0n-Air
key
switches
(Channel
1-4)
-4
each,
push
-
button,
alternate
latching,
SPDT.
Input
se
l
ector
switches
(Channe
l
5)
-
Push-button,
interlocked,
Sx
4PDT.
P.C.
Boards:
(Seven
Total)
Main
Board
Four
Preamp
Boards
(plug-in)
Pot
Board
-
Mixing
busses
and
booster
amp.
Hi
Level
Board
- Hi
level
input
switch,
Power
i
nd
icator
and
VU
meter
leads.
P.C
.
Interconnections:
Flat
Cable
and
Multi-pin
p
lu
gs
.
Audio
Switching:
DC
Controlled
field-effect
transistor
switches
on
Channel
1-
4.
Push
button
switch
on
Channel
5.
Audio
Mute:
DC
controlled
FET
switch.
Size:
Rack
Mount
- 8
11
deep
x 5
1/
4"
high
x
19"
wide
, (
20.
32x
13.
34
x48.
26CM),
Desk
Mount
- 8
11
x 5
1/
2" x 20
1/
4
",
(
20.
32x
l3.
97x51.
44CM)
,
Weig
ht:
14
pounds
(6.35
KG)
Power
Requirements:
117
VAC,
60
Hz
,
100
watts
*Allen-Bradley
MOD
POT,
Hot-molded
element,
rated
at
10
0,000
rotations.
**Graybill
series
46,
rated
at
250,000
operations.
109-01
1
www.SteamPoweredRadio.Com
Studio/Master
505S/505SR
SECTION
II
INSTALLATION
2-
1.
UNPACKING
2-
2.
Remove
packing
material
and
lift
the
console
out
of
the
box.
2-3.
Save
all
packing
material
shou
ld
it
be
necessary
to
ship
the
console
again.
2-4.
MOUNTING
2-5.
Rack
mount
model
panel
mounts
to
rack
with
four
standard
rack
screws.
Vertical
space
required
is
5
1/4
" .
Be
sure
the
rear
apron
of
the
chassis
is
open
for
ventilation
.
The
505SR
should
not
be
mounted
near
any
high
temperature
equipment.
Ambien
t
temperature
should
be
no
higher
than
55
°C
(131°F)
.
2-6.
Desk
mount
model
can
be
set
on
any
level
surface.
The
friction
of
the
rubber
feet
on
the
desk
surface
should
prevent
any
movement
of
the
unit.
2-7.
To
anchor
the
console
to
the
surface,
proceed
as
follows:
a.
Drill
holes
(5/32")
in
the
table
top
at
the
points
where
the
rubber
feet
sit.
b.
Remove
the
screws
from
the
rubber
feet
and
remove
the
feet.
c.
Insert
6-32
screws
up
through
the
holes
in
the
table
top.
(Screws
should
project
1/2
11
to
5/8"
above
the
table).
d.
Place
the
feet
over
the
screws
,
e.
Run
screws
into
the
bottom
of
the
ch
a s
sis
.
2-8.
INPUT ASSIGNMENTS
2-9.
Before
connecting
the
input
lines,
the
input
configuration
should
be
planned.
The
flexibility
of
the
Studio/Master
505S
allows
a
variety
of
con-
figurations.
The
factory
has
pre-set
the
consol
e
for
one
configuration.
2-10.
Figure
2- 1
illustrates
a
typical
input
configuration,
using
the
factory
settings.
2-11.
Table
2
-1
lists
the
factory
settings
of
the
various
jumpers
options.
2-12.
The
input
confirguration
can
be
changed
by
movin
g
jumpers
as
described
in
3-1.
109
-01
1
Section
II
2
-1
www.SteamPoweredRadio.Com
Studio/Master
505S/505SR
Section
II
2-12.
INPUT
CONNECTIONS
CART
c:::J
MO
t-
,:J
2
-1
4.
Phono.
Phono
lines
connect
to
termina
l
barriers
of
Channels
1-
4.
Connect
center
conductor
to+,
Shie
l d
to-.
Ground
lead
connects
to
the
ground
terminal
(G)
at
the
center
of
the
barrier
block
.
Phono
jacks
can
be
installed
on
short
pigtail
l
eads
and
left
attached
to
barriers.
(Supplied
on
Ch.
1 &
2)
2
-1
5.
Microphone.
Mic
li
nes
connect
to
the
terminal
barriers
of
channe
l s 1-
·4.
a.
Connect
3
wire
(low
impedance)
lines
with
white
to+,
black
to
- .
and
shield
to
G.
b.
Connect
2
wire
(high
impedance)
lines
with
center
conductor
to+
and
shield
to
-
or
G.
c . Be
sure
to
defeat
cue
on
mic
channel.
2-
16.
Hi
gh
level
(Unbalanced).
Connect
to
barrier
terminals
of
channel
1-4.
Connect
positive
or
center
conductor
to+,
negative
or
shield
to
-
or
G.
NOTE:
Balanced
inputs
can
be
connected
to
channel
1-4.
One
side
of
the
line
wil
l
be
g
round
e
d.
A
resistor
can
be
placed
across
the
input
t e
rminals
if
termination
is
desired.
CART
TAPE
MIC
PHO
NO
PHONO
c:=i
QP
5T£J:<'c:.O
REMOTES, PHONES,
ETC
.
CH.4
CH. 3 CH. 2 CH. I
REA
R PANEL INPUTS
Fi g
ure
2-1.
T
yp
ic
al
Inpu
t Conf
ir
g
urat
i
on,
U
sin
g
Fac
t
ory
Settings
2- 2
109-011
www.SteamPoweredRadio.Com
Studio/Master
505S/
505SR
Section
II
Table
2
-1
.
FACTORY
SETTINGS
OF
JUMPER OPTIONS
CHANNEL
INPUT LEVEL EQUILIZATION
CUE
MUTE
INTENDED
FOR
1
Lo
RIAA
Yes
No
Phono
2 Lo RIAA
Yes
No
Phono
i\--3
Lo
Flat
No
Yes
Mic
4
Hi
Flat
Yes
No
Hi
level,
Unbalanced
,'c'.5
Hi
Flat
Yes
No
Hi
level,
Balanced
*Channel
3
set
for
mono
source.
All
others
are
Stereo.
**Channel
5
has
no
jumpers
,
settings
are
fixed.
2-17.
Hi
level
(Balanced).
Connect
to
i
nputs
of
channel
5.
Ten
pairs
of
terminal
barriers
are
on
the
rear
apron
for
channel
5
inp
u
ts
A,
B, C, D
and
E.
The
terminals
are
labeled+
and
-
for
phasing
purposes.
The
upper
terminals
are
for
left
channe
l ,
lower
are
for
right
.
NOTE:
Unbalanced
inputs
may
be
connected
to
channel
5
inputs.
The
negative
side
of
the
l i
ne
will
have
to
be
separately
grounded
by
r u
nning
a
jumper
from
the(-)
terminal
to
the
chassis.
2-18.
The
channel
5
inputs
do
not
provide
a
line
term-
ination
load.
Termi
n
ation
resistors
can
be
installed
as
outlined
in
paragraph
4-1.
2-
19.
OUTPUT
CONNECTIONS
2-
20.
Figure
2-2
i l
lustrates
typical
output
connections
.
2-21.
Program.
Connect
to
output
terminals
marked
"program,+,
G,-
. "
Polarity
markings
indicate
phase,
G
is
ground.
Connect
signal
lines
to+
and
- ,
shield
to
G.
(Terminate
shield
at
one
end
only).
2-
22.
Terminate
program
line
in
600
ohms
for
proper
VU
meter
calibration.
2-
23.
Monitor.
Connect
monitor
amplifier
to
11
Monitor
,
+,G
"
terminals.
Shie
l
ded
wire
should
be
used.
Amplifier
may
be
located
several
hundred
feet
away.
109
- 011
2-3
www.SteamPoweredRadio.Com
Studio/Master
505S/505SR
Section
II
2-24.
Set
input
sensitivity
of
monitor
amplifiers
so
they
will
not
overdrive
when
monitor
l
evel
is
full
on.
2-25.
External
muting
relays
are
not
needed
as
the
muting
is
built
into
the
console.
2-26.
On-the-air
light.
Connect
relay
to
operate
warning
light
to
tenninals
labeled
"On-
Air,
G, +DC. '1
The
relay
should
draw
no
more
than
40ma
at
24
volts
(600
ohms
coil).
Observe
that
the
ground
tenninal
is
negative
with
respect
to
the
DC
terminal.
Do
not
connect
115
VAC
to
the
On-
Air
tenninals.
2-
27.
A
diode
should
be
placed
backwards
across
the
relay
coil
to
speed
relay
release.
See
Fig
.
2-2
.
2-28.
Sometimes
the
use
of
a
relay
will
cause
a
"pop"
in
the
program
when
the
microphone
is
keyed.
When
this
occurs,
use
a
lower
current
relay
or
a
solid-state
relay.
(Hamlin
701
-11
-300
or
equal
recommended.)
2-29.
Headphone.
Plug
monitor
headphones
into
the
phone
jack
on
the
rear
panel.
This
is
a
stereo
jack
for
a
three
section
plug
(body
,
ring,
tip).
If
a
monaural
plug
(body,
tip)
is
used
it
should
be
inserted
on
ly
part
way.
Full
insertion
will
short
out
the
signal
.
2-30.
Headphone
impedance
can
be
as
low
as
8
ohms.
For
optimum
performance
600
ohms
is
recommended
.
2-
31.
A
headphone
jack
can
be
mounted
in
a
utility
box
at
the
front
of
the
desk
and
a
line
run
from
the
box
to
the
jack
at
the
rear
of
the
console
to
facilitate
easier
change
of
headsets
. A
pre-
wired
box
is
available
from
Russco
Electronics.
2-32.
POWER
CONNECTION
2-33
Plug
AC
cord
into
any
115
VAC,
60
Hz
outlet.
Dress
AC
cord
away
from
audio
leads,
especially
microphone
and
phono
leads.
2-34
.
GROUND
CONNECTION
2-
35.
Connect
ground
lead
under
chassis
screw
located
on
chassis
bottom,
rear
near
the
fuse
holder.
Use
at
least
18
gauge
wire.
Connect
to
station
ground.
See
figure
2-2.
2
-4
109
-
011
www.SteamPoweredRadio.Com
Studio/Master
505S/505SR
Section
II
2-36.
For
additional
ground
termination
points
(for
shields,
etc.)
a
ground
buss
can
be
installed
across
the
back
of
the
console.
MONITOR
HEADPHONE
a.
Cut
a
piece
of
18
gauge
or
larger
buss
wire,
about
17
inches
long.
b.
Form
it
to
fit
across
the
back
of
the
chassis,
under
the
terminal
barriers.
c.
Anchor
it
under
the
screws
that
hold
the
two
rear
PC
board
supports
on
the
bottom
side
of
the
chassis.
(Spade
lugs
should
be
soldered
to
the
buss
for
anchorin
g
).
d.
Solder
shields
and
grounds
to
the
buss
bar.
NOTE:
This
is
a
static
ground.
Do
not
connect
si
g
nal
grounds
to
the
buss.
ON-A
IR
~
II
___.,__~
0
-o
Xl
-'l•R\
ITC:.
-
LE>'"
'T
f.-1.
IGHT
l I
SVAC
60HZ
REAR
PANEL
STATION
GROUND
Fi
g
ure
2-2
Typical
Output
Connec
t
ions
109-011
2-5
www.SteamPoweredRadio.Com
Studio/Master
50
5
S/50SSR
SECTION
III
CALIBRATI
ON
3-
1 .
JUMPER
SETTINGS
Sect
i
on
I I I
3-
2.
Jumper
locations
are
shown
in
figure
3-
1
thru
3-
4.
3-3.
Table
3- 1
lists
identificat
i on
and
color
coding
of
jumpers.
3-4.
Input
Attenuation
(Fig.
3-
4).
Located
on
the
preamp
PC
boards
behind
the
inp
u t
barrier
terminals.
Install
jumper
appropr
i
ate
to
the
source
l
evel.
Set
right
&
left
cha
nn
els
alike.
3-5.
Equalization
(Fig.
3-4)
.
Located
on
t he
preamp
PC
Boards
next
to
the
preamp
I.e.
's.
Insta
l l
the
jumper
for
the
desired
equilization.
Onl y
one
jumper
should
be
installed
on
each
channel.
One
of
the
jumpers
must
be
instal
l
ed
for
the
preamps
to
operate.
Set
right
&
left
channels
alike.
3-6.
Cue
(Fig.
3-3).
Located
on
top
of
each
pot,
connecting
two
terminals
together.
Remove
the
jumper
to
defeat
the
cue.
To
restore
cue,
solder
a
jumper
between
the
termina
l
s.
3-7.
Mute
(Fi
g.
3-3).
Located
on
the
mixer
PC
board
to
the
left
of
their
respective
mixing
pots.
(Viewed
from
front).
Remove
the
jumper
to
defeat
the
mute.
To
restore
mute,
solder
a
jumper
between
the
terminal
posts.
3-8.
VU
Meter
(Fig.
3-2).
VU
meter
sensitivity
can
be
set
for
+4
or
+8dBm
output
level.
Install
the
appropriate
jumper.
The
+4
jumper
has
been
factory
installed.
Only
one
jumper
shou
l d
be
installed.
3-9.
Transformer
Center-Taps
(Fi
g.
3-2).
Input
and
output
transformer
center
-
taps
can
be
grounded
if
desired.
Grounding
center-taps
may
reduce
noise.
Jumper
posts
are
adjacent
to
transformers.
Install
jumpers
to
ground
the
center
-
taps
.
3-10.
Mono
Source.
These
terminals
are
located
in
a
row
to
the
left
of
each
mixer
pot.
Lettering
these
A,
B,
C
(left
to
right),
Jumper
A
to
B
for
mono,
B
to
C
for
stereo.
3-1
109-011
www.SteamPoweredRadio.Com
Studio/Master
505S/SOSSR
3-11.
LEVEL SETTINGS
(Fig.
3-2)
3-12.
Output.
(Output
must
be
loaded
with
600
ohms
for
proper
calibration).
a.
Use
an
appropriate
level
set
source,
such
as
the
NAB
standard
reference
level
disc,
a
level
set
tape
or
a
genera
tor.
Set
generator
at
-10
or
OdBm
(depending
on
SECTION
III
the
output
level
of
the
studio
equipment)
lKHz
and
connect
to
hi
level
input,
balanced
or
unbalanced
,
left
channe
l .
b.
Rotate
mixer
pot
to
the
desired
physical
position
for
average
level.
(3:00
o'clock
position
is
recommended)
.
c.
Press
on-the-air
button.
d.-
Adjust
left
channel
program
le
ve
l
pot
(on
main
PC
board)
for
OVU
indication.
e.
Repeat
for
right
channel,
leavin
g
mixer
pot
at
same
position.
3-
13
.
Cue
.
a.
Use
appropriate
cue
material
for
source,
such
as
the
lead
-
in
groove
of
a
typical
record
or
head
of
a
typical
tape.
b.
Rotate
mixer
pot
to
cue
(full
counter-
clockwise
position.)
c.
Play
cue
material
.
d.
Adjust
cue
level
pot
for
adequate
volume.
3
-14
.
Headphone.
a.
Average
li
stening
material
such
as
a
typical
musical
selection
would
be
an
appropriate
source.
b.
Set
mixer
pot
for
normal
VU
defle
ction
.
(Between
-10
and
0,
into
red
only
for
peaks).
c.
P
lu
g
in
headset
and
adjust
level
for
comfort-
ab
l e
listening.
Monitor
pot
s
hould
be
at
minimum
setting.
Level
may
have
to
be
set
on
the
high
side
to
satisfy
some
operators.
Right
and
left
channels
are
adjusted
separately.
Be
sure
to
balance
them.
A
mono
record
is
helpful
here.
109-011
3-2
www.SteamPoweredRadio.Com
Studio/Master
505S/505SR
Section
III
Table
3-1 . IDENTIFICATION
AND
COLOR
CODING
OF
JUMPERS
Function
Setting
Identification
Color
Input
Pad
Lo
Level
(Phono
Mic)
Jl
Brown
Hi
Level
(
-l
OdBm)
J2
Red
Equaliza
tion
Flat
J3
Orange
RIAA
J4
Yellow
Cue
JS
Green
Mute
J6
Blue
vu
+4dBm
J7
Violet
+8dBm
J8
Gray
Mono
Source
Splitter
J9
White
Xfrnr.
C.
T.
Ground
JlO
Black
3-3
109-011
www.SteamPoweredRadio.Com
t-'
0
I.O
I
0
t-'
t-'
w
I
~
•
Power
Cord
VU
Meter
Right
VU
Meter
Left
High
Level
Input
Board
Figure
3-1
Output
Terminals
Ri
g
ht
High
Level
Input
Terminals
General
Parts
Locations
Cue
Speaker
Preamp
Inputs
Cl)
rt
C
0..
I-'•
0
-
::s:
PJ
rn
rt
ro
ti
V,
0
V,
Cl)
-
V,
0
V,
C/)
:;i::J
Cl)
ro
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rt
I-'•
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H
H
H
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