LPB Signature II User manual
www.SteamPoweredRadio.Com
I
I
I
I
I
I
Customer
WM
AS
FINAL
TEST
& INSPECTION
REPORT
SIGNATURE
CONSOLE
Mode 1 s-
20
s/n
I O \
Lo\
9
Date
Au
GU
5:.T
20
l I9
~
I
By
/'J1t
.11t
c13
No.
Mic
Preamps 2
Mechanical
Inspection
()/<_
-----
Electrical
Inspection
(!)K
Mic
Channe 1
(ch
1)
(Line
Pot
at
~ .
Master
at
_
}_J
_
_)
Audio
input
for
8
dBm
output
-
SS'
d~M
at
lkHz
Distortion
,
1\5'
percent
at
lkH
z
P&M. l
\.-E:(='.T
C.
\-\ANNE
L
Response
relative
to
]kHz:
2OHz
- .
3<lB
SOOHz
OdB
SkHz
-,
?,d\:)
1
OkHz
- .
bd
\3>
2OkHz - \ d~
Noise
-G;,<o
dB
below
+3dBm
output
Hi
Level
Channel
(ch
Y5
)
(Line
Pot
at
_1
_,
Master
at
Jj__
)
Audio
input
for
8
dBm
output
-\oci~M
at
lkHz
Distortion
.oq
percent
at
lkHz
P&\V\
2.
LEFT
C..
\-\
l\l'J
t--J
~
L
Response
relative
to
lkHz:
2OHz
-
id8,
SOOHz
od~
SkHz
-.
\ d~
JO
k
Hz
-.
~
d
~
2OkHz - \dB
Noise
-(og
dB
below
+8dBm
output
I
Functions:
I
I
I
I
I
I
Monitor
O
((
Cue
A
11
inputs
OK
Phones _ O_K
__
Muting
Relay
_ 0~
(<
..._
__
_
A-l
1
outputs
DI<
On-Air
Contacts
C>I<
www.SteamPoweredRadio.Com
LPB
s-~n
AUDIO
CONSOLE
FEATURES
Designed
and
manufactured
to
a high level
of
operational
capability
and
electronic/
mechanical
reliability
for
the master
control
requirements
of
broadcasting
and
production.
Extensive human engineering
and
years
of
experience in console design have been
combined
to
provide
the
operator
with
a console which
is
both
visually appealing
and
easy to operate.
Internally,
the approach
is
similar
with
immediate visual
identification
and
ease
of
access
to
every
component
and
connection
in the console.
I:
www.SteamPoweredRadio.Com
r
LPB
Manufacturers
and
Di
stribu
tor
s
of
Broadcast
Equipment
Pl
•
8
Signature
II
Consoles
uti
li
ze
t
hese
cl
assic
human engineered control
knobs which readily
conform
to
the
grasp. Position markings
al
l
ow
immediate recognition
of
level set-
tings at a glance
from
any
direction
.
Panel markings are black epoxy silk
screened over the .125 inch
thick
deep grained and brushed
aluminum
front
panel, and overcoated
with
clear epoxy
for
additional per-
manence
of
markings.
Al I program buss switches are rugged tel
e-
phone-type roller
cam
design
with
gold
alloy contacts.
Additional
closure contacts
are provided
for
internal relay
muting
or
are wired
to
terminal strips
for
external
co
ntrol
of
cartridge machines, turntables,
etc.
A unique feature
of
the SignatureII Stereo Con-
soles
is
the mono/stereo input switch located
behind the
front
panel,
which
enables a
mono
source
to
be
split
to
the
left
and
right
program
busses.
These selectors are provided
for
each
microphone-capable channel and one high level channel.
The
Card
Edge Connectors are molded
of
high stab
ii
ity
diallyl phthalate and the contacts are phosphor bronze,
with
gold over copper plating. The contacts are
of
the
"tuning-fork"
variety
with
controlled
lateral
float,
main-
taining positive
continuity
of
contacts and provides suffi-
cient elastic reserve
to
prevent the contacts
from
becoming
"set."
All
I.C.
sockets feature gas-tight connection
contact
geometry
with
tin-alloy
plated copper contacts. The min-
iature toggle switches
used
for
microphone
input
gain
selection, stereo/mono
input
switching and
mono
mixdown
are Mil-Spec types
with
solid coin silver contacts and
terminals which feature a
minimum
of
200,000
cycles
of
operation. (S-20
input
circuit
assembly shown)
The rotary step attenuators are
2dB
per step,
20
steps,
with
appropriate tapers at either end
of
the
control
range. The
contacts are solid silver
alloy
and a laminated
rotor
is
used
to
produce
an
exceptional
ly
low
noise figure
of
-125
dBm.
A stainless steei shaft
with
free-turning sleeve-type bearings
provides constant knob tension.
Signature
II
8 and 10
mixer
consoles feature 3 position
input selector switches givi
ng
24 and 30
input
source
capability
.
An
exclusive manu-
facturing
technique
cal
l
ed
"wedgelock"
contact
fastening
secures the stationary
contact
to
prevent loosening and
rotation
of
contacts. Spring tempered
si
lver
alloy
contacts and coin 8
silver
rotor
blades have a mini- C
mum
lifetime
of
250,000
cycles if
of
operation.
A
The plug-in microphone preamp incorporates switch
selectable preamp gain
to
allow
instant level matching
to
--45,
-55
and
-65
dB
microphone
sensitivity l
eve
ls.
All
microphone
inputs are coupled
with
a dual shielded, high
RF suppression transformer. All active
circuitry
is
located
on plug-
in
modules
for
flexibility
and
ease
of
maintenance.
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
www.SteamPoweredRadio.Com
LPB
Serving the Broadcast Industry since
1960
The printed circuit
boards
are 2 ounce
copperclad G-10
fiber
glass
laminate,
tin
lead electroplated. Internal
wire
con-
nections are soldered
to
silver plated
miniature
turret
terminals,and
al
I internal
wiring
is
multiple-strand, 100%
foil
shielded. The monitor power output
transistors
are heat-sunk
to
the chassis
rear panel
for
maximum
heat dissipa-
tion.
(S-20
output
c
ircuit
assembly
shown)
A feature
of
the Model
S-20 10
mixer
dual stereo
conso
le
is
the
ability
to
add
an
optional
output
line
amplifier
which
will
provide a mono mixdown,
switch selectable,
of
either
the stereo program
(Pl)
or
audition
(P2)
busses.
other
S~ell
console
features
OUTPUT
DIRECTOR
SWITCH: Dual Consoles have a three
position
output
director
switch on the
audition
output
lin
e,
oth
er
consoles have th
is
switch on the program
output
Iine.
INTERNAL
CUE SYSTEM: A
5"
speaker and 1
watt
power
ampI
ifier
are located
within
the console
to
provide high
quality
audio
performance.
MUTING
AND
TALLY
RELAYS: Rugged telephon
e-
typ
e relays
are
uti
lized and are socket
mounted
for
ease
of
maintenance.
POWER
TRANSFORMER:
The
power
supply and transformer
is
completely internal
to
the consol
e,
and the transformer
is
spe
cifically designed
for
low
field
operation
and has
mylar
interwinding
insulation
for
protection
aga
in
st
transient damage.
CHASSIS CONSTRUCTION: Consoles are constructed
complete
ly
of
aluminum
alloy,
with
wood
grain
formica
and
vinyl
covered
warp free end panels attach
ed
to
the metal end plates.
MODULAR
ELECTRONICS:
All
active signal processing circu
itr
y
is
"plug-in,"
and located on 2
"mother
board"
ma
in
frame
assemblies. 5 types
of
plug-in modules are
utilized
for
micro-
phone preamps,
ba
lanced high l
eve
l inputs,
lin
e
outputs,
voltage regulator,
monitor
output
drivers and cue amp
lifi
er
functions.
DUAL
LINE
LEVEL
OUTPUTS:
All
audition
(P2)
outputs
of
Signature
11
Series consol
es
are balanced
lin
e level and metered,
identical in performance
to
the main program
(Pl)
output
WARRANTEE
: LPB guarantees
your
complete satisfaction
upon
receipt and
wi
ll provide any necessary repairs at
our
factory,
without
charge
for
one year.
High brightness LED
peak
audio
level
indicators are
located in
each
ii
luminat
ed
VU
meter and may
be
set
by the user
to
flash at any desired l
eve
l.
oA o
P2
~
Pl
() 0
s
D
.
• •
2 8
• •
LPB
"
MODEL
S-21
TEN MIXER
DUAl
MONO
CONSOLE
~
~
P2
P1
Ct
. $
'
••
• •
1 a
• •
All
input-output connections are made
to
screw ter-
minal barrier strips clear
ly
identified
to
aid
in
wir
in
g
withou
t reference
to
the manual. The console harness
cables are also identified and correspond
to
the
internal
circuit
board
wiring
point
markings and the
wir
ing diagram.
+ +
llBR
9GL
' \ + +
1 8BL
9BR
' G G \
+ + \
8AR
9CL
+ + '\
~
8Al
9CR
\\t
+ +
7CR
+ + ' \
www.SteamPoweredRadio.Com
MODEL
S-
12 MODE L
S-
1
4A
5 MIXER STEREO 5
MIXER
MONO
MOD;
L·S
-1
3E
- -
-~-
..
. MODE L S-15A
8 MIXER STEREO/MONO 8 MIXER DU
AL
MONO
MODEL
S-20
10
MIXER DUA L ST
ER
EO
LPB
LPB
Inc.
28 Bacton Hill Road, Frazer,
Pa
. 19355 (215)
644
-
1123
MODEL S-13C
INTERIOR
6/77
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
www.SteamPoweredRadio.Com
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
Signature
II
10
MIXER
DUAL
STEREO
CONSOLE
MODEL
S-20
• 30 Inputs • Step Attenuators • Plug-In Modules •
Led
Peak
Indicators • Switch Selectable Mic Gain •
•
All
Transformer Inputs and
Outputs
• Demonstrated RF
Immunity
• Prewired
for
Simulcast
Option
•
The
LPB
Model S-20 10
Mixer
Dual Stereo Console
accepts a
total
of
30
transformer coupled audio inputs, 3
to
each
of
the 10 mixers. As shipped,
mixer
1 accepts 3
switched stereo microphone inputs and mixers 2 through
10 accept 3 switched stereo high level inputs
eac
h.
Mixers
2 through 4, however, can
each
accept 3 switched micro-
phone inputs
by
substituting the standard plug-in high level
input
boards
with
available microphone preamp plug-ins.
Monitor
speaker
muting
and
tally
relays are provided
for
mixers 1 through 3, and mixers 4 through 10 incorporate
remote switch contacts. Mixers 1 through 4 are internally
switch selectable
to
mono
or
stereo,
as
well
as
mixer
10
which includes a talkback line.
A cue position
is
provided on every
mixer
and the S-20
includes
an
internal cue system consisting
of
a cue
amplifier,
level
control
and 5 inch speaker. A phone jack mounted
on the rear panel provides headphone
monitoring
of
pro-
gram,
audition
and
cue
with
its
own
level co
ntrol.
The
internal stereo
monitor
amplifier
is
switch selectable
to
monitor
program,
audition
or
an
external line. The il-
luminated
VU
meters are switched simultaneously
with
the
monitor
selector in the program and
audition
positions
and
return
to
read
the program line in the external position
of
the
monitor
selector.
The program,
audition
and
optional
mono
mixdown
performance specifications
are
identical,
with
the
mono
mixdown
amplifier
switch selectable
to
provide a mono
sum
of
either
the
program or
audition
outputs. The pro-
gram and
audition
outputs
each
have a master level
control
on the
front
panel,
with
the
audition
output
being fed
to
a
3-position
output
director
switch. Program,
audition,
headphone
and
cue
buss
auxiIiary
outputs
are also provided.
Light
em
itting
diode
peak level indicators are standard,
located in the
VU
meters, and may
be
adjusted
to
fire at
various level thresholds.
All
connections
to
the S-20
are
made through barrier strip screw connections located
within
the console.
www.SteamPoweredRadio.Com
SPECIFICATIONS
Mixers
Total. .
With
Cue
....
.
Type
..
...
..
.
Inputs
. .
..
.
.............
10 Stereo
...
.
..
. .
.....
.
......
.
..
10
. . . . . . .
..
.Step
Attenuator
Standard Factory Equipped
Mic (Mono/Stereo) . . . . . . . . . .
......
...
..
3
Hi-Level.
.......
.
.....
.
......
.
.......
27
Optional Maximum
Mic (Mono/Stereo) . . . . . . . . .
....
.
..
.
..
12
Hi-Level.
.............
.
.......
.
.....
.30
Total.
.. ..
.
...
..
..
.
..
.
..
.
......
. .
..
. . .
30
Input Impedance
Mic. . .
.......
. .
....
150 ohms source, Trans. Bal.
Hi-Level.
..
. .
... ...
.
......
600 ohms, Trans. Bal.
Input Levels
Mic. .
...
. . . . selectable: -45 dBm, -55 dBm, -65 dBm
Hi-Level. . . . . . . . . . . . . . . . . . . . . . .-10 dBm
Remote/Net
...
..
. . .
..
....
.
....
.
...
.-10 dBm
Outputs
Program
(P1)
.
Audition
(P2).
.stereo, +8 dBm (Ovu}, clipping level
above +22 dBm
. . stereo, +8 dBm (Ovu), clipping
l
evel
above +22 dBm
Opt. Mono
Mixdown
....
.
...
+8 dBm (Ovu}, clipping
Monitor
. .
.....
.
Cue
..
......
.
Headphones . . .
Output
Impedance
level
above +22 dBm
. 4 Stereo@ 12 watts per channel
1 @1
watt
with
5"
Internal Speaker
1,
switchable between Program,
Audition
or
Cue
Program.
....
. . . .
..
.
......
600 ohms, Trans. Bal.
Audition
..
.
...
. .
..
.......
600 ohms, Trans. Bal.
Opt. Mono
Mixdown
.....
.
...
600 ohms, Trans. Bal.
Monitor.
. . . . . . . . . .
....
....
...
2
to
8 ohms
Headphones
.....
.
....
. . . . . . . . 200 ohms and up
Frequency Response
Program
..
.
.....
.
...
..
..
± 1.0 dB 20 Hz - 20 kHz
Audition
...
.
......
..
. . .± 1.0 dB 20
Hz
-20 kHz
Opt. Mono
Mixdown
....
...
± 1.0 dB 20
Hz
-20 kHz
Monitor
.....
.
..........
±1.5dB
20
Hz-15
kHz
;=fJ-
---:-:-
~~1;:
~
l<C-
=---+:;-
...r1_,
-;-
---'71=:=~'---
- ~ .
:>----
----r----4;--
~
. '
i ' s -
--
·
C
''
I
·
~·;
J
II
S _
~
C I ' I
. ,
-,
.
.-
"'
·=
=
r1~f;r
;ifft-~
111rr
11
·~
s
~~~;-
~
' . s
..
:~ :
C :
El
f M
ON
T
AUIIIIA
C
II
i -
--
- -
---t--t+--'
LPB
Inc.
Total Harmonic Distortion
Program,
Audition,
Opt.
Mono
Mixdown
....
.
.....
Typ
. 0.2%, 0.5% Max.,
20
Hz
-20
kHz@
18 dBm Output,
-55 dBm
Input
Monitor
.
....
. .
..
. . .
..
1.5% Max., 20
Hz
to
15 kHz
J.M.
Distortion
Program,
Audition,
Opt
.
Mono
Mixdown
......
. L
ess
than .15%@ +22 dBm
Output
Level
Monitor
.
..
.
..........
.
Less
than 0.2%@12 watts
Signal To Noise
Program,
Audition
, Opt.
Mono
Mixdown
..
.Better than 74 dB below +18 dBm
Output
with
-50 dBm
Input
20
Hz
-20 kHz
Crosstalk
Program
to
Audition
and
Monitor
.
....
.........
..
Below noise
level
Power Requirements .
Voltage
.........
.
..
117
VAC
(234
VAC
available}
Frequency
......
.
..
..
.
...
..
.
....
..
50/60
Hz
Power
.......
..
...........
. .
...
.
..
70 watts
Dimensions
Width . .
...
.
..
. . . .
..
......
.. ..
. . . .
38-3/4"
Height. . . . . . . . . . . . . . .
...
... ...
....
9"
Depth . . .
....
.....
. . . .
..
....
..
. . . .
...
15"
Weight. . . . . . . . . .
...........
..
....
60 lbs.
Plug-In Modules
Types
..
. .
.....
..
Mic Preamp, Hi-Level Input, Line
Amp,
Power
Amp,
Voltage Regulator
Total Number. .
..............
..
..
..
. .
...
17
Cabinet
Material . .
..
...
.
.. ..
...
..
..
. 0.
125"
Aluminum
Finish . . . Textured scratch resistant "champagne
gray"
Armorhide® exterior, gold anodiz
ed
interior
Panel
"'
~
HONI
O<J
T
Material
........
.
....
.
......
0.125"
Aluminum
Finish .
...
Horizontally ground and brushed aluminum,
black epoxy silk screening
with
protective
clear epoxy overcoat.
Model
S-
20
Con
so
le
Int
erior
The S-20 Console
top
cover and
front
panel hinge
open
to
allow
immediate
access
to
all
circuit
com-
ponents
and
the
labeled
input/output
screw terminals.
LPB
®
28
Bacton
Hill Road, Frazer,
Pa.
19355 (215) 644-1123
8/79
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
www.SteamPoweredRadio.Com
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
LPB
LED
PEAK
LEVEL
INDICATOR
MODEL
SA-1
J
0
• ~
JI
\'. :o!·.
LPB
' :
o!
.·.:1
. . . .
Model
SA-1
Kit
FEATURES
'
..
,
..
Available installed in
LPB
consoles
or
in
kit
form
Utilizes
ultra
-high
luminance
light
emitting
d
io
de
Adjustable
peak level trigger
Pulse
stret
c
her
enhanc
es
display
of
rap
id
tr
ansients
Model
SA-1
as
installed
in
meter
faces
of
LPB
Audio
Consoles
The LPB Model
SA
-1
LED
P
eak
Level
Indicator
is
designed
to
allow
the
operator
of
Audio
Control
equ
ipment
to
be
aware
of
actual peak lev
els
at and be
yond
a pre-set reference level. This
indication
, especially when
use
d in
conjunction
with
an
audio con
so
le
will
sh
ow
h
ow
" h
ar
d"
a peak signal
limiter
is
being driven.
Although
de
si
gn
ed
p
rim
ar
ily
to
be connected across a
VU
meter, the SA-1 may
be
connect
ed ac
ross
virtually
any audio
s
our
ce
prov
iding
a
sig
nal
of
0.4
to
6
VRMS
without
unbalancing
or
loading
that
source. +24
VDC
is required
for
powering
the
SA
-1, wh
ic
h dra
ws
nomin
a
lly
15 ma. The
LED
display may
be
panel
or
meter
mounted
through
a .189 diameter
hole (# 12
drill
).
Wh
en insta
ll
ed in LPB consoles,
the
LED
display
is
mounted
in the
VU
meter.
SPECIFICATI
O
NS
INPU
T IMP
EDANC
E:
500,000
o
hm
s bridging, balanced
or
unbalanced
INPUT SI
GNA
L
RE
Q
UIRED
0.4 to 6
VRMS
TRI
GGER
LEVEL
R
AN
G
E:
Adjustable
+3dBm
to
+28dBm
POWER SUPPLY
REQUIR
EMENTS
: Norn. 24
VDC
at 15 ma. avg. (5 ma
to
30
ma
peak)
SI
ZE AND
MOUN
TING: Cir
cu
it
board 2-1/
8"
x
3"
with
90°
MTG
BKTS
on 1-5/8 centers, .187 red
LED,
mounts
in panel thickness 1/ 16
to
3/ 16
SET-UP
(Aud
io Console
or
s
imilar
600
ohm
referenced audio
equipment)
Conn
ec
t a sine wave
gene
rator
se
t at 1
kHz
to
the console
input
. Set
the
generator
or
console
ga
in level
to
provide the
peak o
ut
put
l
eve
l you wish
to
mon
i
tor
.
Adjust
the
potentiometers
so
that
the
LED
ju
st lights (do
not
turn
beyond
thi
s poi
nt
).
Example: On a
ty
pical console (0
VU
=
+8dBm)
,
the
generator level should be set
for
a console
output
of
+16dBm. Wi
th
th
is
se
tt
ing,
the
LED
will
illuminate
whenever a peak reaches
or
exceeds 8
VU
.
NOTE
:
The
VU
meter
w
ill
be
r
ea
din
g
off
scale at
this
level.
Other methods to adjust
for
peak signal
detection
would
be
to
set
the
trigger level
to
coincide
with
100%
transmitter
modulat
ion or 3% T
HD
level
for
recording.
LPB
Inc.
28
Bacton Hill Road, Frazer, PA.
19355
(215) 644-1123 2
/7
7
www.SteamPoweredRadio.Com
LED
PEAK
LEVEL
INDICATOR
MODEL
SA-1
REGULATED
R160
B+C+24V>---------11--------------'\.fVu__.,
__
R156
+
.__
...
C25
-
0-j
....,,+""'-+--a--4
TO
VU
·R152
C28
METER
RlS
3
+
C>--1
t--+'VVvo--------4
C26
Rl52,
153
Rl
54,
155
R156
Rl57
Rl58
Rl59
R160
C25,
26
C27
C28
AS
QlO
D15
-
-
-
-
R157
PEAK
ADJUST
R158
PARTS
LIST
Resistor,
lOOK
ohm,
l/2w,
5%
11
300K
ohm,
l/2w,
5%
11
, 1
SOK
ohm,
1/
2w,
5%
Potentiometer;
lOK
ohm,
1
inear
taper
Resistor,
12K
ohm,
l/2w,
5%
11
,
lOK
ohm,
l/2w,
5%
11
, 470
ohm,
2w,
5%
Capacitor,
1.0 mfd,
20
vdc,
electrolytic
II
100 mfd,
20
vdc,
electrolytic
II
47
mfd,
35
vdc,
electrolytic
Dual
Op
Amp,
uA747PC
(or
equivalent)
Transistor,
2N3904
LED,
high
intensity,
red,
2 vdc
LPB
® LPB, Inc.
28
Bacton Hill.
Road
Frazer, PA. 19355
(215) 644-1123
010
3/
77
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
www.SteamPoweredRadio.Com
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
INSTRUCTION
MANUAL
LPB
MODEL
S-20
10-MIXER
DUAL
STEREO
.
AUDIO
CONSOLE
1.0
SUMMARY
The
LPB
Model
S-20 10-mlxer Dual
Stereo
Audio Console
ls
directed
to
the
master
control
requirements
of
stereo
broadcasters.
It
accomodates
many
special
requirements.
The
ten
mixers
are
switchable
Into
two
Identical
program
busses,
identified
as
Pl
and
P2
(or
PGMl
and
PGM2).
Two
identical
stereo
program
busses,
coupled
with
m
et
er
and
monitor
ampl
lfler
s
witchin
g,
produce a dual
console
which
wl
11
simultaneously:
Fe
ed program
to
the
transmitter
(using
Pl),
and
Allow
production
of
other
material
for
later
air
use
(using
P2).
Many
other
features
make
this
console
very
flexible
and
convenient
to
use.
A
mono
mlxdown
option
Is
also
aval
lab
le.
Refer to
the
enclosed
catalogue
sheet,
drawings and
text
for
detailed
descriptive
Information.
2.0
GUARANTEE
Upon
receipt
of
this
equipment
we
guarantee
that
you
will
find
the
ap-
pearance,
workmanship and
standards
of
materials
and
construction
in keep-
ing
with
the
application
and
with
good
standards
of
conmercial
practice.
For a
period
of
one
year
from
date
of
del
Ivery,
we
guarantee
this
equipment
against
any form
of
failure,
provided
that,
In
the
opinion
of
the
manufacturer,
no
improper use
of
or
modification
to
the
equipment
is
at
fault.
During
this
period,
we
will
furnish
the
materials
and
labor
In
our
shops
to
correct
any
failure.
If
need
for
service
arises,
CONTACT
LPB
for
permission
to
return
and
for
shipping
Instructions
BEFORE
shipping.
Note
that
shipping
charges
are
not
covered
by
our
guarantee
and
that
we
assume
no
responsibll
lty
for
cor-
rec
tion
of
shipping
damages,
especially
those
which
may
r
esult
from
the
user
1s
choice
of
a
mode
of
shipment
other
than
that
recommended
by
LPB.
Prompt
delivery
of
replacement
p
art
s
is
always
available
for
out-of
-
warranty
equipment,
as
are
fac
tory
repa
ir
s .
Contact
LPB
for
current
prices.
5-20 page 1
www.SteamPoweredRadio.Com
3.0
UPON
RECEIPT
that:
4.0
Upon
receipt,
immediately
unpack and
in
s
pect
the
console
to
be
certain
a.
Everything
is
complete,
as
ordered,
and
as
itemized
on
the
Packing
List.
b.
No
damage has
occurred
in
transit
to
you.
If
there
is~
damage,
retain
all
packing
materials
and
immediately
notify
the
carrier
in
writing
and
by
telephone,
with
a copy
to
LPB.
c.
You
are
satisfied
with
the
overall
quality
and
appearance
of
the
console.
INSTALLATION
This
section
of
your
S-20
console
manual
describes
al
1
aspects
of
wiring
the
console
into
your
facilities
and
preparing
for
actual
use.
4.1
DEFINITIONS
To
better
understand
the
instructions
and
illustrations,
a
list
of
definitions
of
some
co1M10nly
confused
terms
is
included.
These
are
ref-
erenced
to
this
console
and
may
not
apply
to
other
equipment.
S-20
1. .Channel -Each
of
the
two
signals
that
comprise
a
stereo
program,
Left
and
Right.
2.
Mixer
-
The
circuits
in
the
console
that
take
the
input
signals
and
feeds
them
into
the
busses
at
a
control
led
level.
3. Fader -
The
gain
controlling
device
of
a
given
mixer
circuit.
In
this
case,
tw
o
channel
step
attenuators.
4.
B
uss
-The
point
in
the
console
where
signals
from
the
mixers
are
combined.
S.
Muted and
Un-Mut
ed -
To
prevent
feedback,
in
certain
control
positions,
either
monitor
or
cue
speakers
or
both
are
disabled.
Output
connections
are
available
for
both
monitor
conditions,
depending
on
studio
layout.
6. Program -
Historically
defined
as
the
signal
fed
to
the
transmitter.
Since
the
S-20 has two
outputs
which
can
be used
for
this,
both
are
named
program
but
one
is
usually
used
for
production
or
audition.
page
2
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
www.SteamPoweredRadio.Com
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
4.2
CONNECTION
TO
THE
AC
POWER
SOURCE
The
MAIN
POWER
SWITCH,
FUSE
and
POWER
CORD
are
to
the
right
rear
of
the
console.
The power
cord
is
of
the
three-wire
type
w
ith
an
Internal
safety
grounding
pin.
DO
NOT
REMOVE
THE
-
GROUNDING
PIN
from
the
power
cord,
as
a
safety
hazard
is
presented
and
the
equipment
warranty
is
void.
The
main
Fuse,
Fl,
is
a
type
AGC
2
AMP.
Another
fuse,
F2,
will
be
found on
the
output
base
board
Inside
the
console.
It
is
a
1/4
AMP
fuse
~nd
is
in
series
with
the
lamp
bulbs
in
the
VU
meters
only.
Both
of
these
fu
s
es
are
standard
fuses,
DO
NOT
USE
SLO-BLOW
fuses
.
4.3
INPUT
IMPEDANCES
AND
INPUT
LEVELS
Al
1
inputs
and
outputs
of
the
LPB
S-20
Dual
Stereo
Console
are
trans-
former
balanced.
The
microphone
inputs
are
150
ohm;
all
other
inputs
and
the
program
outputs
are
600 ohm.
Unbalanced
low
impedance
audio
sources
may
be
connected
directly
to
any
input
of
the
S-20.
Unbalanced
high
impedance
audio
sources,
such
as
TEAC
and
other
tape
recorders,
may
be
connected
to
a
high
level
input
of
the
S-20
console
only
through
an impedance
matching
transformer.
See
Figure
A
for
an example
of
this
type
of
connection.
The
S-20
console
is
designed
for
conventional
-SSdBm
Input
level
mic-
rophones and
-lOdBm
"high
level"
sources.
Some
audio
sources
may
not
pro-
vide
outputs
at
these
levels.
Consult
the
manual on each
of
your
audio
sources.
It
is
desirable
that
all
inputs
be
at
-55dBm
or
-IOdBm
level
so
that
all
mixer
step
attenuators
operate
in
about
the
same
position,
usually
about
11
1:30
o'clock".
An
example
is
an
Ampex
AG-600B
open-reel
tape
recorder
whose
output
is
600
ohms
balanced
at
+4dBm.
An
attenuator
pad
of
14dB
attenuation
is
de-
sired
between
the
AG-6008
output
and
the
high
level
input
of
the
S-20.
Figure
Bl
shows such
balanced
11
H
pads"
and
tabulates
resistor
values
for
se
veral.
Another
example,
in
the
case
of
microphone
inputs,
might
be
the
use
of
a
Sennheiser
MKE
402
Electret
Condenser
Ca
r
dioid
Microphone whose
output
is
rated
at
-49dBm.
This
calls
for
a
6dB
"H
pad"
attenuator
between
the
mic-
rophone and
the
microphone
input
of
the
console.
This example
is
shown in
Figure
B2.
S-20 page 3
www.SteamPoweredRadio.Com
4.4
INPUT/OUTPUT
CONNECTIONS
A
11
input
and
output
connections
to
the
console
are
made
to
screw
terminal
barrier
strips
along
the
inside
bottom
of
the
main frame
of
the
console.
Slots
adjacent
to
these
barrier
strips
al
low
the
passage
of
audio
wire
from under
the
console
to
the
strips.
Shielded
twisted-pair
audio
wire,
such
as
2-conductor
Belden
"Beldfoil"
#8451
(AWG
22
stranded
of
7
strands
AWG
30)
or
#8450
(AWG
22
sol
id)
or
4-conductor
11
Beldfoil
11
#8723
(stranded)
should
be used
for
all
audio
input
and o
utput
connections.
The
sol
id
wire
will
be somewhat
easier
to
handle
and
will
more
readily
retain
the
shape
to
which
it
may
be
bent
around
cor-
n~rs.
Equivalent
Columbia
stranded
numbers
are
257
6
for
2-conductor
and
2523
for
4-conductor.
An
excellent
choice
of
wire
type
from
the
monitor
amplifier
output
to
speakers
Is
conventional
AWG
18
stranded
"Zip
cord"
as
used
for
household
lamps,
etc.
Figure
C shows
the
locations
of
input/output
connections.
The
30
stereo
input
pairs,
plus
a number
of
conmen
grounding
points,
are
found
on
the
seven
barrier
strips
to
the
left
of
the
main
frame.
The
marking
of
these
is
interpreted
as
follows,
using
input
8BL
as
an example:
8
references
an
input
to
the
#8
mixer.
B
references
the
11
8
11
input
to
mixer
#8,
out
of
the
three
(A'
!,
&
C)
available.
L
references
the
left
channel
input
pair
of
wires.
+ -
'
references
phasing
of
this
input
pair.
G
references
.9..round
connections.
Note
that
it
is
recommended
that
the
shield
of
all
audio
intercon
n
ection
cables
be
grounded
only
at
the
console
end
to
avoid
ground loops
with
at-
tend
a
nt
noise
and
hum
problems.
Toward
the
right
of
the
console,
on
6
barrier
screw
terminal
strips,
are
the
output
and
control
connections.
Several
exampl es
fol
low
to
clari-
fy
the
interpretation
of
the
markings :
PIL & PIR:
MONO
+,
-
Ml
X I C
AUX
NO
s-20
Left
and
tight
channel
output
pairs
of
the~
pr
ogra
m amps.
Mono
mixed
down
output
pair,
phased.
Mixer
#1
auxil
lary
switching
contacts,
corrmon
and
normally
£Pen,
which
are
closed
upon moving
the
Pl-OFF-P2
switch
from
the
OFF
position,
used
to
control
ON
AIR
1
ights
or
other
outboard
equipment
starting.
(See,
for
an
example,
Figure
D)
page 4
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
www.SteamPoweredRadio.Com
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
MUTED
L
MON
1 R
P2LB
+,-
AUX
L
PHONE
R
EXT
L
MON
IN
R
CUE
BUSS
PGM
1 L
TAPE
OUT
R
MIX
4
AUX
C
NO
.!:_eft, ,!_ight and
common
(3..round)
connections
for
a
monitor
speaker
which
ls
muted upon moving
the
Pl-OFF-P2
switch
above
mixer.!_
from
the
OFF
position.
Left
stereo
output
from
the
P2
program
amplifier,
with
the
output
direction
swi~ch In t
he!
po
s
ition
(of
A,
B & C),
phased.
Alternate
or
auxiliary
connection
point
for
headphone
monitor,
L & R s
tereo
pairs
(unbalanced).
Input
to
the
console
from
external
of
f-the-ai
r
monitor
receiver,
L & R
stereo
pairs(unbalanced)
.
Access
to
the
cue
buss
for
use
of
an
outboard
cue
amp-
I
ifier,
if
desired
or
to
put
a
source,
such
as
an
Intercom,
into
the
console
cue
amp
I
ifier
and
speaker.
This
buss
is
high
Impedance. A
-22dBm
input
to
it
produces
approximately
1W
to
the
cue
speaker.
Unbalanced
fl
output
at
about
IV, L &
R,
suitable
for
tape
recording
directly
from
the
program I
buss.
Mixer
#4
auxiliary
switching
contacts,
common
and
nor-
mally
£Pe;:-as
MIX
1
AUX
described
previously,
except
that
the
auxl
llary
contacts
for
mixers
#1
-
#3
are
via
relays
while
for
mixers
#4
-#10
are
from
spare
contacts
on
the
P1-0FF-P2
switches
4.5
SET-UP
FOR
OPERATION
Input
Switching:
To
either
side
of
the
VU
meters
along
the
top
of
the
front
panel
are
located
the
ten
inp
ut
switches,
each
numbered I
thru
10
to
correspond
with
mixers
1
thru
10. Each
input
switch
al
lows
the
selection
of
on
e
of
three
inputs
to
that
mixer,
designated
A,
B &
C.
Reference
to
the
circuit
diagram
shows
that
the
input
switching
is
performed ahead
of
the
input
plug-in
modules
in
mixers
1
thru
4 and ahead
of
the
input
trans-
formers
on
5
thru
10.
Plug-In
Modules, Mixers 1
thru
4:
Two
plug-in
module
positions
are
provid
ed
for
each
mixer,
1
thru
4.
These
are
left
and
right
channel
plug-in
s ,
allowing
choice
of
microphone
level
or
high
level
input
to
each
of
these
mixers.
As
priced,
the
S-20
Console
is
supplied
with
two
micro-
phone
input
plug-in
modules
for
mixer 1, and
high
level
plug-in
modules
for
mixers
2,
3 and
4.
Al
I
console
Inputs
are
transformer-matched.
Select
the
appropriate
plug-in
modules
for
mixers
I
thru
4
for
your
re-
quirements.
S-20 page 5
www.SteamPoweredRadio.Com
Stereo/Mono Mic/Mono Hi-L
Switches,
Mixers 1
thru
4:
These
three-
position
miniature
toggle
switches
wi
11
be found
adjacent
to
the
plug
-in
modules
for
mixers
1
thru
4,
on
the
input
base
board
behind
the
front
panel.
With
the
appropriate
plug-in
module in
place
(microphone
or
high
level,
as
described
abov
e)
these
switche
-s
allow
selection
of
stereo
or
mono
functioning
of
the
in
dividual
mi
xe
r.
Mono
operation
might be
de-
sired
for
mono
mic,
mono
cart
machine,
etc.
In
mono,
the
input
is
connected
to
the
appropriate
left
input
and
is
split
equally
to
both
left
and
right
stereo
program
channefs:"
Stereo/Mono
Switch,
Mixer
which
is
found
to
the
right
end
or
mono
operation
of
mixer
10.
machine
or
remote 1
ine
inputs.
10:
Similar
to
the
above,
this
switch,
of
the
input
base
board,
allows
stereo
Mono
operation
may
be
desired
for
cart
In
mono,
the
input
Is
connected
lOBL
or
lOCL,
and
is
split
equally
to
ch~nels.
-
to
Input
connections
labeled
lOAL,
both
left
and
right
stereo
program
PGM
2
OUTPUT
Switch:
To
the
right
of
the
mixer
10
input
selector
switch
will
be found a
green
handled
3-position
switch
marked
PGM
2
OUTPUT,
A,
B,
C.
This
is
an
output
director
switch
for
PGM
2,
to
allow
direction
of
PGM
2
output
to
a
choice
of
three
loads,
such
as
an
open-reel
recorder,
cart
machine,
etc.
Mono
Mixdown, P1/P2: The S-20
console
is
wired
to
accept
an addi -
tional
1
ine
output
plug-in
module on
the
m~in
base
board
to
provide
mono
mixdown
of
the
left
and
right
channel
outputs
of
either
Pl
or
P2.
The
Pl/P2
sele
ction
is
by
a
nother
miniature
toggle
switch
locat
ed
adjacent
to
the
mono
mixdo
wn
plug-in
module on
the
main
base
board.
The
mono
mixdown
arnpl
ifier
has
no
separate
gain
control
of
its
own.
When
the
mixdown
select
switch
has been
set
to
either
PGMl
or
PGM2,
the
setting
of
·
the
appropriate
Program
Master
control
determines
the
output
level
of
the
mixdown
amplifier.
When
both
the
left
and
right
program
levels
are
+SdBm,
the
mono
output
wi
11
be
+8dBm.
As
priced,
the
S-20
con
sole
is
not
supplied
with
this
mono
mixdown
plug-in
module.
Remote/Network
Inputs,
Mixer 10: Mixer
10
and
its
associated
inputs,
lOA,
108
and
lOC,
are
normally
used
for
network arid remote 1
ines.
Inputs
lOA
and
10B
would
normally
be used
for
remotes
and
lOC
for
a network
input.
Inputs
IOA
and
10B
have
talkback
capability.
When
the
input
switch
for
mixer
10
is
in
the
IOA
position,
the
Le
f t
Monitor
signal
is
present
on
input
terminals
108.
When
the
input
switch
is
in
the
108
position,
talkb
ack
is
present
on
input
terminals
IOA.
The
level
is
dependent
on
the
setting
of
the
Monitor
Volume
control,
with
the
maximum
being
+8d8m
into
600 ohms.
S-20 page 6
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
www.SteamPoweredRadio.Com
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
4.6
SPEAKER
MUTING,
ON
AIR
LIGHT
CONTROL
AND
REMOTE
CONTROL
In
typical
operation,
the
console
oper
ator's
microphone
will
be on
mixer
I,
input
IA.
Since
feedback
can
occur
from
cue
and
monitor
speakers
to
microphone,
provision
is
made
to
avoid
this.
When
mixer
I
input
switch
is
in
the
A
position,
the
cue
for
mixer
1 and
the
MUTED
MONITOR
I
speakers
are
disabled
in
either
position
of
the
program
selecto
r
switch.
In
the
center
(or
off)
positi
on
of
the
program
selector
sw
i
tch,
only
the
cue
is
disabled.
In
the
Band
C po
sitions
of
the
mi
x
er
l
input
switch
,
these
functions
a
re
not
disabled.
If
microphones
are
fe
d
to
the
se
inputs
from remote
locations,
the
cons
ole
opera
t
or
will
be a
ble
to
ut
i
lize
the cue and
monitor
functions
of
the
console
without
the
use
of
he
adphones.
Relays
are
provided
within
the
console
to
accomplish
muting
functions,
independently,
for
mixers
1,
2 and
3.
Refer
to
Section
4.
4
for
description
of t he
terminals,
designated
MIX
1
AUX,
etc.
Operators
oft
en w
ant,
for
example,
the
turntable
motor
to
be
turned
on
automatically
when
t he
switch
over
mixer
7 (presuming
the
turntable
in-
put
to
be
connected
to
input
7A,
7B
or
7C)
is
moved
from
OFF
to
either
Pl
or
P2. Auxi
llary
switch
contacts
are
wired
into
the
console
input/output
connection
strips
for
this
purpose.
See
Figure
D
for
outboard
control
via
the
auxiliary
switching
con-
tacts.
AC
powered
loads,
such
as
ON
AIR
1
ight
bulbs
or
turntable
motors
s
hould
not
be run
directly
through
the
console.
An
outboard
24V
DC
power
s
upply
and
secondary
control
relays
are
conventional
for
this
purpose.
The
left
and
right
program I
ine
output
transformers
for
Pl
and
P2
and
the
mono
1
ine
output
transformer
all
have
center
taps
which
are
brought
o
ut
to
the
console
barrier
strip.
These
center
taps
can
be
used
for
S
impl
ex remote
control
through
a
balanced
audio
1
ine
with
de
continuity.
Se
e
Figure
E
for
Si m
plex
hookup method. Note:
The
relay
used
should
have
a
sensitive
coil
with
a high de
resistanc
e
to
I
im
i t
current
flow in
the
transformers
to
a
safe
value
of
50
ma
maximum.
5
.0
OPERATION
OF
THE
CONSOLE
This
section
references
the
operator's
us
e
of
front
panel
controls
in the
operation
of
the
S-20
Console.
5
.1
CO
NTROL
SETTINGS
The S-20
Console
utilizes
stereo
step
attenuator
faders
in
all
ten
mi
x
er
circuits
and
stereo
potentiometers
for
PG
M I and
PGM
2
master
gain
S- 20 page 7
www.SteamPoweredRadio.Com
controls.
(To
accoroodate any
variations
in
the
gain
of
the
circuits
within
the
console
used
for
the
left
and
right
channels,
the
user
wi
11
find
inter-
nal trimmer
potentiometers
on
the
main
base
board
adjacent
to
each
left
and
right
I ine
output
plug-in
module.)
Typical
operation
wi
1I
find
these
faders
and
masters
set
at
aJ
out
1:30
o'clock
for
program
ma
te
rial
peaking
11
0
VU
11
on
the
meters.
Set
~ings
experienced
in
final
test
of
your
console
wi
11
be
found on
the
Final
Test
Report,
included
with
t
his
manual.
A
CUE
VOLume
control
is
adjacent
to
the
program
masters
on
the
upper
right
of
the
panel.
The
MONitor SELect .
rotary
switch
with
positions
labeled
PGM
1,
PGM
2
and
EXT
is
to
the
upper
left
of
the
front
panel.
This
switch
simultaneously
controls
the
inputs
to
the
VU
meters
and
monitor
amp!
ifiers,
both
of
which
are
moved
from
PGM
l
to
PGM
2.
In
the
EXT
position,
only
the
monitor
moves
to
the
EXTernal
monitor
input
to
the
console
while
the
VU
meters
return
to
rea
d
PGM
l
console
output
levels.
MONitor
VOLume,
PHONE
VOLume
and
the
PHONE
selector
(PGM
l -
PGM
2 -
CUE)
switch
are
also
found
to
the
upper
left
of
the
panel.
The
cue
speaker
is
to
the
left
rear
of
the
console.
A
nearby
headphone
jack
is
provided
for
headphones
of
200
ohms
or
greater
impedance.
5.2
PROGRAM
OUTPUT
CHARACTERISTICS
A
reading
of
O on
the
VU
meters
corresponds
to
+BdBm
at
the
program
outputs
of
the
console.
The
PGM
2
OUTPUT
switch
(A
- B -
C)
(see
Section
4.4)
al
lows
the
di-
rection
of
PGM
2
output
to
a
choice
of
three
loads.
The
program l
output
is
not
switch
directable.
This
output
is
nor-
mally
the
transmitter
audio
feed.
5.3
MONliOR
OUTPUT
CHARACTERISTICS
The
internal
stereo
monitor
amp
I
ifier
is
rated
at
12
watts
per
channel
into
4
ohm
loads.
Although
separately
muted
for
mixers
1, 2 and
3,
all
monitor
speakers
operate
in
parallel
on
the
output
of
the
amplifier.
The
equ i
va
1
ent
para
11
e 1 impedance
of
the
various
speakers
that
the
user
may
elect
to
utilize
on
the
console
should
be
held
to
not
less
than
2
ohms
per
channel.
Note
that
UNMUTED
MONitor
output
terminals
are
also
provded
within
the
console
to
drive
a lobby
speaker,
etc.
S-20 page 8
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
www.SteamPoweredRadio.Com
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
Speaker
leads
carry
high
currents
because
of
the
low
impedance
levels
of
the
speakers.
These
leads
should
be
routed
away
from program
output
w
ires,
and
especially
from
inputs.
6.0
MAINTENANCE
You
have
invest
ed a
considerable
sum
of
money
in your
LPB
S-20
Dual
Stereo
Console.
It
is a
hlgh-qual
ity
hand-crafted
electronic
unit
of
which you can
expect
to
be
proud
for
many
years.
To
expect
this
equipment
to
maintain
original
appearance
and
perform
reliably
requires
certain
minimums
of
care
in
the
routine
hand! Ing
of
the
equipment and a
bit
of
oc-
casional
maintenance.
The
panel
of
the
S-20 Console
ls
sllkscreeen
marked In baked epoxy
with
a
clear
ba
ked epoxy
overspray
for
additional
protection.
Use
no
sol-
vents
on
the
panel.
Detergent
cleaners
such
as
11
409
11
are
quite
safe
and
satisfactory,
as
is
"Windex
11
for
removal
of
any
stains
from
the
panel.
Care
should
be
taken
that
a
minimum
of
dirt
collects
inside
the
con-
sole.
An
occasional
vacuuming Is recorrmended.
Quarterly,
we
reconmend
that
the
step
attenuator
rear
dust
covers
be removed and
the
contacts
cleaned.
The
contact
s
of
the
several
printed
circuit
plug-in
modules
should
also
be
cleaned
once
or
twice
each
year.
Many
excellent
areosol
contact
cleaners
are
available
for
this
purpose.
No
other
routine
main-
tenance
is
needed• .
When
removing
or
replac
'ing
plug-in
printed
circuit
modules,
turn
the
console
power
OFF
to
avoid
any
possible
circuit
damage from
transients.
6.
I
CIRCUIT
DIAGRAM
AND
PARTS
LIST
A
complete
circuit
diagram
Is
furnished
with
this
manual.
Refer
to
it
f
or
details
of
switching
functions,
etc.
A
complete
parts
1
ist
tabulation
also
fol
lows. A
price
list
for
re-
pla
cement
parts
is
impossible
to
publish
because
of
rapid
changes In
our
co
sts
from
suppliers.
LPB
will
be
pleased
to
quote
current
parts
costs
in
response
to
your inqu i
ry.
Your
console
has been
tested
in
detail
at
the
factory
prior
to
ship-
ment,
as
the
enclosed
Final
Test
Report
indicates.
If
any problems
are
experienced
or
suspected,
please
call
LPB
inmediately.
S-20 page 9
www.SteamPoweredRadio.Com
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
Figure
A
TEAC,
Sony,
CONNECTING
AN
UNBALANCED
HIGH
IMPEDANCE
AUDIO
SOURCE
etc.
High
)
....
,
z )
I~
600
ohm
use
shielded
i
use
tw
sted
wire
-
here
wire
here
High Impedance
to
600
ohm
transformer,
such
as
UTC
0-1
Figure
B-1
ACCOMODATING
HIGH-OUTPUT
HIGH-LEVEL
AUDIO
SOURCES
+4dBm
R2
oo
DD
0 0
600Q
balanced
Rl
Rl
Rl
Rl
Ampex
AG-600B
11
H
11
pad
attenuator
source
1eve
l,
dBm
dB
1
ass
R1,
ohms
-7
3
51
-4
6
100
-1
9
150
+2
12
180
+5
15
200
+8
18
220
-lOdBm
ba
l.
600Q
R2,
ohms
1600
820
470
330
220
150
[use
this
pad
for
the
Ampex
AG-600B
example above
600 Q
input
of
Console
600 Q
input
of
Console
Other manuals for Signature II
1
This manual suits for next models
1
Table of contents
Other LPB Recording Equipment manuals
