Lpb Signature ii User manual

STEAM POWERED RADIO.COM

I

INSTRIJCTION

MIINIJlll

~J[

AUDIO

CONSOLE

®

LPB

LPB Inc.

28

Bacton

Hill

Road

.,

Frazer,

Pa

.

19355

(~i)

6411123

1,~

?4L/·

//

J.$

5-

ao- .

MODEL

PRICE

$10.00

STEAM POWERED RADIO.COM

I

FINAL

TEST

& INSPECTION

REPORT

SIGNATURE

CONSOLE

Customer

WM

AS

Mode 1 s-

2.0

s/n

I O \

L-\

9

Date

AvGU~T

20

1 I9 g I

By

l'J1t.

11t'/3

No.

Mic

Preamps 2

Mechanical

Inspection

Cf<.

Electrical

Inspection

(!;)

K

--

Mic

Channel

(ch

l)

(Line

Pot

at

~ '

Master

at

J..:j_

) P&M. \

\.-E:~T

Audio

input

for

8

dBm

output

-SS'd

~

M

at

l kHz

C.

\-\ANNE

L

Distortion

,

I\$'

percent

at

]kH

z

Response

relative

to

lkHz:

20Hz - .

3<l~

SOOHz

046

SkHz

-,

~d~

l OkHz - . bdG 20kHz - 1

d~

Noise

-'7(o dB

below

+3dBm

output

Hi

Leve

1

Channel

(ch

1-/

e, )

(Line

Pot

at

_l

_,

Master

at

}.j_

)

Audio

input

for

8

dBm

output

-\O~~M

at

!kHz

P&tv\

2.

LEFT

C.

\-\

l\flJ

~

e_

L

Functions:

Distortion

.

oq

percent

at

lkHz

Response

relative

to

!kHz:

20Hz -i

dB

SOOHz

od~

SkHz

-.

\ d~

10

k

Hz

-

.1

d~ 20kHz -\dB

Noise

-(og

dB

below

+8dBm

output

Monitor

01<.

Cue

Phones _ 0

--"-

K

__

Muting

Relay

_ O

=....

/(

.,__

__

_

All

inputs

OK

A~

1

outputs

Of<

On-Air

Contacts

C>I<

---=-~----

STEAM POWERED RADIO.COM

LPB

S-~Il

AUDIO

CONSOLE

FEATURES

LPB

s-~

n

Mo

C°"'chA

...

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.

STEAM POWERED RADIO.COM

LPB

Manufacturers

and

Distributors

of

Broadcast

Equipment

Pl

•

8

Signature

Il

Consoles

utilize

these

classic human engineered control

knobs which readily

conform

to

the

grasp. Position markings

allow

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 tele-

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

control

of

cartridge machines, turntables,

etc.

A unique feature

of

the Signature

TI

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 posit

iv

e

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

sol

id

coin

si

lver 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

exceptiona

lly

low

noise figure

of

-125

dBm.

A stainless

steel

shaft

with

free-turning sleeve-type bearings

provides constant knob tension.

Signature IT 8

and

10

mixer

consol

es

feature 3 position

input selector switches giving 24 and 30

input

source

capability.

An

exclusive manu-

facturing technique called

"wedgelock"

contact fastening

secures the stationary contact

to

prevent loosening

and

rotation

of

contacts. Spring tempered

si

lver alloy contacts

and

coin

silver

rotor

blades have a

mini-

mum

lifetime

of

250,000

cycles

of

operation. t,

8

C

•

A

B

~

The plug-in microphone preamp incorporates switch

selectable preamp gain

to

allow

instant level matching

to

--45,

-55

and

-65

dB

microphone sensitivity levels. All

microphone inputs are coupl

ed

with

a dual shielded, high

RF suppression transformer. AlI acti

ve

circuitry

is

located

on plug-

in

modules

for

flexibility

and

ease

of

ma

intenance.

I

STEAM POWERED RADIO.COM

/

LPB

Serving the Broadcast Indus

tr

y since

1960

The printed circuit

boards

are 2 ounce

coppercl

ad

G-10

fiber

gl

ass

l

am

inate,

tin

lead electroplated. Internal

wire

con-

nections are

so

ldered

to

silver plated

miniature

turret

terminals,and alI internal

wiring

is

mul

tip

le-strand, 100%

foil

shielded. The monitor power output

transistors

are heat-sunk

to

the chassis

rear panel

for

maximum

heat di

ss

ipa-

tion.

(S-20

output

circuit

assembly

shown)

A feature

of

the Model

S-20 10

mixer

dual stereo

console

is

the abil i

ty

to

add

an

opt

ional

output

line

amplifier

which

wi

ll

provide a mono mixdown,

switch selectable,

of

either

the stereo program

(P

1)

or

audition

(P2)

busses.

other

S~ell

console features

OUTPUT

DIRECTOR

SWITCH: Dual Consoles have a t

hr

ee

position

output

director

switch on the

audition

output

lin

e,

other

consol

es

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

aud io

performance.

MUTING

AND

TALLY

RELAYS: Rugged tel

ep

hon

e-type relays

are

utilized

and are socket

mounted

for

ease

of

maintenance.

POWER

TRANSFORMER:

The

power

supply and transformer

is

comple

tely

internal

to

the console, and the transformer

is

specifically designed

for

low

field

operation

and has

mylar

interwinding

insulation

for

protection

against transient damage.

CHASSIS CONSTRUCTION: Consoles are constructed

completely

of

aluminum

alloy,

with

wood

grain

formica

and

vinyl

covered

warp free end panels attached

to

the metal end plates.

MODULAR

ELECTRONICS:

All

active signal processing c

ir

cu

itry

is

"plug-in,"

and located on 2

"mother

board"

main frame

assemblies. 5 types

of

plug-in modules are

uti

lized

for

micro-

phone preamps, balanced high level inputs, line

outputs,

voltage

regu

l

ator,

monitor

output

drivers and cue ampl

ifier

functions.

DUAL

LINE

LEVEL

OUTPUTS:

All

audition

(P2)

outputs

of

Signature 11Series consol

es

are balanced line level and metered,

identical in performance

to

the main program (P1)

output.

WARRANTEE:

LPB guarantees

your

complete satisfaction

upon

receipt and

will

provide any necessary repairs at

our

factory,

without

charge

for

one year.

H

igh

brightness LED

peak

audio

level

indicators are

located in

each

iiluminated

VU

meter and may

be

set

by the user

to

flash at any desired level.

cA o

P2

~

Pl

(D 0

s

D

.

• •

2 8

• •

LPB

"

MODEL

5·21

TEN MIXER

DUAL

MONO

CONSOLE

0 a e

P2

~

Pl

0 $

'

••

• •

1 a

• •

All

input-output connections are made

to

screw ter-

minal barrier strips clearly

identified

to

aid

in

wiring

without

reference

to

the manual. The console harn

ess

ca

bl

es

are al

so

identified and correspond

to

the

int

ernal

circuit

board

wiring

point

markings and the

wiring

diagram.

+ +

llBR

9RL

+ +

BBL

9BR

G G

+ +

8

AR

9CL

+ +

8Al

9C

R

G

+

10Al

+ +

STEAM POWERED RADIO.COM

MODEL

S-

12

MODEL

S-

1

4A

5 MIXER STEREO 5 MIX

ER

MONO

--

MODE L S-13C -MODEL S-

15A

8 MIXER STEREO/MONO 8 MIXER

DUAL

MONO

MODEL

S-20

10

MIXER

DUAL

STEREO

r

LPB

'-

LPB

Inc.

28 Bacton Hill Road, Frazer,

Pa.

19355 (215)

644

-1123

MODEL

S-

13C

INTERIOR

6/77

I

~

I

~

I

STEAM POWERED RADIO.COM

I

Signature

II

LPB®

10

MIXER

DUAL

STEREO

CONSOLE

·•

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MODEL

S-20

,:.-;

,.

,(

.

..

n,,

,~

•

• 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 each. 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

mix

er 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 c

ontrol.

The

internal stereo

monitor

amplifier

is

switch

sel

ec

table

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

ext

ernal 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

audit

ion

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

e

mitting

diode

peak level indicators are standard,

located in

th

e

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

th

e console.

STEAM POWERED RADIO.COM

SPECIFICATIONS

Mixers

Total.

.....

.

.......

.. ..

.

...

.

.....

10 Stereo

With

Cue

....

.

...

.

..

.

...

.

..

.

....

. .

..

. . . 10

Type

...

. .

.. .. .. ..

. .

..

.

...

..

.Step

Attenuator

Inputs

Standard Factory Equipped

Mic (Mono/Stereo)

...

..

.........

. . .3

Hi-Level. . . . . . . . .

...

.

..

. .

.....

27

Optional Maximum

Mic (Mono/Stereo)

..

.

.....

. . . . . .

..

. 12

Hi-Level.

...

.

...

. .

.....

...

.

..

. .

...

.

..

30

Total. .

..

.

...

..........

.

.....

.

...

. .30

Input Impedance

Mic.

..

. . .

..

.

Hi-Leve

l.

. . . . .

Input Levels

. . . 150 ohms source, Trans. Bal.

..

....

..

600 ohms, Trans. Bal.

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

lev

el above +22 dBm

Opt. Mono

Mixdown

..

......

+8 dBm (Ovu), clipping

level

above +22 dBm

Mo

nitor

..

.

....

..

4 Stereo@ 12 watts per channel

Cu

e. . .

....

.

..

. 1 @1

watt

with

5"

Int

ernal Speaker

Headphones

...

.

.. ..

1, switchable be

tw

ee

n Program,

Audition

or

Cu

e

Output

Impedance

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 Mix

down

. .

..

±1.0 dB 20 Hz - 20 kHz

Monitor

. . .

..

.

...

.

..

.

..

.±1.5 dB 20 Hz - 15 kHz

LPB

Inc.

Total Harmonic Distortion

Program,

Audition,

Opt

.

Mono Mix

down

....

. .

...

. Typ. 0.2%, 0.5%

Ma

x.

,

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

es

sthan .15%@+22 dBm

Output

Level

Monitor

..

.

....

.

......

. Le

ss

than 0.2%@12 watts

Signal

To

Noise

Program,

Audition,

Opt.

Mono Mix

down

...

Be

tt

er 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

Ty

p

es

....

. . . . . . . Mic

Pr

eamp,

Hi-L

eve

l Input, Line

Amp,

Power

Amp,

Voltage Regulator

Total Number

..

. .

..

.

...

.

...

.

.....

. .

...

. .

17

Cabinet

Material

..

. .

.....

...

. . . .

..

. . 0.

125"

Aluminum

Finish

..

. Tex

tur

ed scratch

re

sistant "champagne gray"

Armorhide® exterior, gold anodiz

ed

int

erior

Panel

Material

...

. .

..

.........

...

. 0.

125"

Aluminum

Finish . . . . Ho

ri

zo

ntally ground

and

brushed aluminum,

black epoxy silk sc

re

ening

with

prot

ec

tiv

e

cl

ear epoxy overcoat.

Model S-20 Console

Int

erior

Th

e S-

20

Console top cover and

front

panel hin

ge

open

to

allow i

mm

e

diat

e ac

ces

s

to

all circuit com-

ponents and

th

e labeled

input

/o

utput

s

cr

ew te

rm

inal

s.

LPB®

28

Bacton

Hill Road, Frazer,

Pa.

19355 (215) 644-1123 8/79

I

STEAM POWERED RADIO.COM

I

LPB

LED

PEAK

LEVEL

INDICATOR

MODEL

SA-1

j

0

-.&-

.

.:.I,;

..

Y. O

i

LPB

' 0

-~,.

. . . .

.·

I

: • 1 '

Model

SA-1

Kit

FEATURES

. . . .

, j 10

'"'

Available

installed

in

LPB

consoles

or

in

kit

form

Utilizes ultra-high luminance

light

emitting

diode

Adjustable

peak level trigger

Pulse

stretcher

enhances display

of

rapid

transients

Model

SA-1

as

installed

in

meter

faces

of

LPB

Audio

Consoles

The LPB Model

SA

-1

LED

Peak

Level

Indicator

is

designed

to

allow

the

operator

of

Audio

Control

equipment

to

be

aware

of

actual peak levels at and

beyond

a pre-set reference level. This

indication,

especially when

used

in

conjunction

with

an

audio console

will

show

how

"hard"

a peak signal

limiter

is

being driven.

Although

designed

primarily

to

be

connected across a

VU

meter, the SA-1 may

be

connected across

virtually

any audio

source

providing

a signal

of

0.4

to

6 V RMS

without

unbalancing

or

loading

that

source. +24

VDC

is

required

for

powering

the

SA

-1,

which

draws

nominally

15 ma. The

LED

display may be panel

or

meter

mounted

through

a .

189

diameter

hole (#

12

drill).

When installed in LPB consoles, the

LED

display

is

mounted

in the

VU

meter.

SPEC!

FICATIONS:

INPUT

IMPEDANCE

:

500,000

ohms bridging, balanced

or

unbalanced

INPUT

SIGNAL

REQUIRED

0.4

to

6

VRMS

TRIGGER

LEVEL

RANGE

: Adjustable

+3dBm

to

+28dBm

POWER SUPPLY

REQUIREMENTS:

Norn. 24

VDC

at 15 ma.

avg.

(5 ma

to

30

ma peak)

SIZE

AND

MOUNTING:

Circuit

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

(Audio

Con

so

le

or

similar

600

ohm

referenced audio

equipment)

Connect a sine wave generator set at 1

kHz

to

the console

input

. Set the generator

or

console gain level

to

provide the

peak

output

level you wish

to

monitor.

Adjust

the

potentiometers

so

that

the

LED

just lights (do

not

turn

beyond

this

point)

. Exampl

e:

On a

typical

console (0

VU

=

+8dBm),

the

generator level should be set

for

a console

output

of

+16dBm.

With

this

setting,

the

LED

will

illuminate

whenever a peak reaches

or

exceeds 8

VU.

NOTE:

The

VU

meter

will

be

reading

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

modulation

or

3%

THO

level

for

recording.

LPB Inc.

28

Bacton Hill Road, Frazer, PA.

19355

(215) 644-1123

2/77

STEAM POWERED RADIO.COM

LED

PEAK

LEVEL

INDICATOR

MODEL

SA-1

REGULATED

R160

B+(+24V)

__________

.......,...,__

___

'VV~----

R156

C25

-~l....l'l+~

..........

TO

VU

'

Rl

52

C28

METER

Rl

5J

+

~

---+"""-----,!

10

C26

R152, 1

53

R154, 155

R156

R157

R158

R159

R160

C25,

26

C27

C28

AS

Q10

015

PEAK

ADJUST

-

R158

PARTS

LIST

Resistor,

100K

ohm, 1/2w, 5%

11

300K

ohm,

1/2w,

5%

11

, 1

SOK

ohm, 1/2w, 5%

Potentiometer;

10K

ohm, 1

inear

taper

Resistor,

12K

ohm, 1/2w, 5%

11

,

10K

ohm,

1/2w,

5%

11

, 470 ohm,

2w,

5%

Capacitor,

1

.0

mfd,

20

vdc,

electrolytic

11

100 mfd,

20

vdc,

electrolytic

11

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

LED

D15,tN

010

-

.

3/

77

I

STEAM POWERED RADIO.COM

I

INSTRUCTION

MANUAL

LPB

MODEL

S-20

JO-MIXER

DUAL

STEREO

.

AUDIO

CONSOLE

1.0

SUMMARY

The

LPB

Model

S-20 10-mlxer

Dual

Stereo

Audio Console Is

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 me

ter

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

ai

r 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

conmerclal

practice.

For a

period

of

one

year

from

date

of

delivery,

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

responslbll

lty

for

cor-

rection

of

shipping

damages,

especially

those

which

may

r

esult

from

the

user's

choice

of

a

mode

of

shipment

other

than

that

recommended

by

LPB.

Prompt

delivery

of

replacement pa

rts

is

always

available

for

out-of

-

warranty

equipment,

as

are

factory

repa

ir

s. Contact

LPB

for

current

prices.

S-20

pag

e l

STEAM POWERED RADIO.COM

3.0

UPON

RECEIPT

that:

4.0

Upon

receipt,

immediately unpack and ins

pect

the

console

to

be

certain

a.

Everything

is

complete,

as

ordered,

and

as

itemized

on

the

Packing

Li

st.

b.

No

damage

ha

s

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 1

ist

of

definitions

of

some

co1TVT10nly

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.

5. 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

STEAM POWERED RADIO.COM

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

with

an

internal

safety

grounding

pin.

DO

NOT

REMOVE

THE

-

GROUNDING

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

nnd

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

-lOdBm

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-6008

open-reel

tape

recorder

whose

output

is

600

ohms

balanced

at

+4dBm.

An

attenuator

pad

of

14d8

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

s

everal.

Another

example,

in

the

case

of

microphone

inputs,

might

be

the

use

of

a

Sennheiser

MKE

402

Electret

Condenser

Cardioid

Microphone whose

output

is

rated

at

-49dBm.

This

calls

for

a

6dB

11

H

pad"

attenuator

between

the

mic-

rophone and

the

microphone

input

of

the

console.

This

example

is

shown

in

Figure

82.

S-20 page 3

STEAM POWERED RADIO.COM

4.4

INPUT/OUTPUT

CONNECTIONS

All

input

and

output

connection

s

to

the

console

are

m

ade

to

screw

te

rminal

barrier

strips

along

the

inside

bottom of

the

main frame

of

the

console.

Slots

adjacent

to

these

barrier

strips

allow

the

p

ass

age

of

audio

wire

from

under

the

console

to

the

strips.

Shielded

twist

ed-

pair

audio

wire,

such

as

2-conductor

Be

lden

"Beldfoil"

#

8451

(AWG

22

stranded

of

7

strands

A~/G

30)

or

#84

50

(AWG

22

sol

id)

or

4-conductor

'_

'Beldfoil"

#8

723

(stranded)

shoul d 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-

ners.

Equivalent

Columb

ia

stranded

numbers

are

2576

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

strand

ed

"Zip

cord"

as

used

for

household

lamps,

etc.

Figure

C shows

the

lo

c

ations

of

input/output

connections.

The

30

stereo

input

pairs,

plus

a number

of

common

grounding

points,

are

found on

the

seven

barrier

strips

to

the

left

of

the

main

frame.

The

marking

of

t h

ese

is

interpreted

as

follows,

using

input

8BL

as

an exampl e:

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

pa

ir

of

wires.

+ -

I

references

phasing

of

this

input

pair.

G

references

.9..round

connections.

Note

that

it

is

recommended

that

the

shield

of

all

audio

intercon

ection

cables

be

grounded

only

at

the

console

end

to

avoid

ground loops

with

at-

tend

a

nt

noise

and

hum

problems.

Towa

rd

the

right

of

the

console,

on

6

barrier

screw

terminal

st

rips,

are

the

output

and

control

connections.

Several

exampl es fo l

low

to

clari-

fy

the

interpretation

of

the

markings :

Pl

l & PIR:

MONO

+,··

Ml

X I C

AUX

NO

S-20

Left

and

~ight

channel

outp

ut

pairs

of

the~

progra

m amps.

Mono

mixed

down

output

pair,

phased.

Mixer

#1

auxiliary

switching

contacts,

corrmon

and

normally

£Pen,

which

are

closed

upon moving

the

P1-0FF-P2

switch

from

the

OFF

position,

used

to

control

ON

AIR

lights

or

other

outboard

equipment

starting.

(See,

for

an example,

Figure

D)

page 4

I

STEAM POWERED RADIO.COM

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

Left,

,!_ight and

common

(g_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

switch

in

t

he.!!_

position

(of

A,

B & C),

phased.

Alternate

or

auxiliary

connection

point

for

headphone

monitor,

L & R

stereo

pairs

(unbalanced).

Input

to

the

console

from

external

of

f-the-air

monitor

receiver,

L & R

stereo

pairs(unbalanced)

.

Access

to

the

cue buss

for

use

of

an

outboard

cue

amp-

1

ifier,

if

desired

or

to

put

a

source,

such

as

an

Intercom,

into

the

console

cue

amplifier

and

speaker.

This

buss

is

high

impedance. A

-22dBm

input

to

it

produces

approximately

lW

to

the

cue

speaker.

Unbalanced

fl

output

at

about

lV, L &

R,

suitable

for

tape

recording

directly

from

the

program 1

buss.

Mixer

#4

auxiliary

switching

contacts,

common

and

nor-

mally

.5Peii-;-as

MIX

1

AUX

described

previously,

except

that

the

auxiliary

contacts

for

mixers

#1

-

#3

are

via

relays

while

for

mixers

#4

-

#10

are

from

spare

contacts

on

the

Pl-OFF-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

input

switches,

each

numbered 1

thru

10

to

correspond

with

mixers

1

thru

10. Each

Input

switch

allows

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 i

nput

plug-in

modules

for

mixer 1, and

high

level

plug-in

modules

for

mixers

2, 3 and

4.

Al

1

console

Inputs

are

transformer-matched.

Select

the

appropriate

plug-in

modules

for

mixers

1

thru

4

for

your

re-

quirements.

S-20 page 5

STEAM POWERED RADIO.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

above)

these

switche

·s

allow

selection

of

stereo

or

mono

functioning

of

the

individual

mixer.

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

line

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

cha'-;:;-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

wi

11

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,

Pl/P2:

The S-20

console

is

wired

to

accept

an

addi-

t i

onal

I

ine

output

plug-in

module on

the

m

LJ

in

base

board

to

provide

mono

mixdown

of

the

left

and

right

channel

outputs

of

either

Pl

or

P2.

The

Pl/P2

selection

is

by

another

miniature

toggle

switch

locat

ed

adjacent

to

the

mono

mixdown

plug-in

module on

the

main

base

board.

The

mono

mixdown

arnpl

ifier

has

no

separate

gain

control

of

its

own.

Wh

en

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

amp!

ifier.

When

both

the

left

and

right

program

levels

are

+SdBm,

the

mono

output

wi

11

be

+8dBm.

As

priced,

the

S-20

console

is

not

supplied

with

this

mono

mixdown

plug-in

module.

Remote/Network

Inputs,

Mixer 10: Mixer

10

and

its

associated

inputs,

JOA,

10B

and

lOC,

are

normally

used

for

network

arid remote 1

ines.

Inputs

JOA

and

10B

would

normally

be used

for

remotes

and

IOC

for

a network

input.

Inputs

JOA

and 108 have

talkback

capability.

When

the

input

switch

for

mixer

10

is

in

the

JOA

position,

the

Left

Monitor

signal

is

present

on

input

terminals

108.

When

the

input

switch

is

in

the

108

position,

talkb

ack

is

present

on

input

terminals

lOA.

The

level

is

dependent

on

the

setting

of

the

Monitor

Volume

control,

with

the

maximum

being

+8dBm

into

600 ohms.

S-20 page 6

I

STEAM POWERED RADIO.COM

I

4.6

SPEAKER

MUTING,

ON

AIR

LIGHT

CONTROL

AND

REMOTE

CONTROL

In

typical

operation,

the

console

operator's

microphone

will

be on

mixer

1,

input

IA.

Since

feedback

can

occur

from

cue

and

monitor

speakers

to

microphone,

provision

is

made

to

avoid

this.

When

mixer 1

input

switch

is

in

the

A

position,

the

cue

for

mixer 1 and

the

MUTED

MONITOR

1

speakers

are

disabled

in

either

position

of

the

program

selector

switch.

In

the

center

(or

off)

position

of

the

program

selector

switch,

only

the

cue

is

disabled.

In

the

Band

C

positions

of

the

mixer 1

input

switch,

these

functions

are

not

disabled.

If

microphones

are

fed

to

the

se

inputs

from remote

locations,

the

console

operator

will

be

able

to

utilize

the

cue and

monitor

functions

of

the

console

without

the

use

of

headphones.

Relays

are

provided

within

the

console

to

accomplish

muting

functions,

independently,

for

mixers

l,

2 and 3.

Refer

to

Section

4.4

for

description

of

the

terminals,

designated

MIX

1

AUX,

etc.

Operators

oft

en w

ant,

for

example,

the

turntable

motor

to

be

turned

on

automatically

when

the

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

auxillary

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

supply

and

secondary

control

relays

are

conventional

for

this

purpose.

The

left

and

right

program 1

ine

output

transformers

for

Pl

and

P2

and

the

mono

1

ine

output

transformer

all

have

center

taps

which

are

brought

out

to

the

console

barrier

strip.

These

center

taps

can be used

for

Simplex remote

control

through

a

balanced

audio

1

ine

with

de

continuity.

Se

e

Figure

E

for

Si

mp

lex

hookup method. Note:

The

relay

used

should

have

a

sensitive

coil

with

a high de

resistanceto

I

im

it

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

use

of

front

panel

controls

in

the

operation

of

the

S-20

Console.

5. l CO

NTROL

SETTINGS

The S-20 Console

utilizes

stereo

step

attenuator

faders

in

all

ten

mixer

circuits

and

stereo

potentiometers

for

PG

t1

l and

PGM

2

master

gain

S-

20

page 7

STEAM POWERED RADIO.COM

controls.

(To

accorrodate 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

1

ine

output

plug-in

module.)

Typical

operation

wi

11

find

these

faders

and

masters

set

at

aJ

out

1:30

o'clock

for

program

ma

teria

l

peaking

11

0

VU

11

on

the

meters.

Set~i

ngs

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

adjac

ent

to

the

program

masters

on

the

upper

right

of

the

panel.

The

MONitor

SELec

t .

rotary

switch

with

positions

labeled

PGM

1,

PGM

2

and

EXT

is

to

the

upper

left

of

the

fron

t

panel.

This

switch

simultaneously

controls

the

inputs

to

the

VU

meters

and

monitor

amplifiers,

both

of

which

are

moved

from

PGM

I

to

PGM

2.

In

the

EXT

posit

ion,

only

the

monitor

moves

to

the

EXTernal

monitor

input

to

the

console

while

the

VU

meters

return

to

rea

d

PGM

1

console

output

levels.

MONitor

VOLume,

PHONE

VOLume

and

the

PHONE

selector

(PGM

1 -

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

outpu

t s

of

the

console.

The

PGM

2

OUTPU

T

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

MONITOR

OUTPUT

CHARACTERISTICS

The

internal

ste

reo

monitor

amp

I

ifier

is

rated

at

12

watts

per

channel

i

nto

4

ohm

loads.

Although

separately

muted

for

mixers

I,

2 and 3,

all

monitor

speakers

operate

in

parallel

on

the

output

of

the

amplifier.

The

equivalent

parallel

impe

da

nce

of

the

various

speakers

that

the

user

may

elect

to

utilize

on

the

console

should

be

held

to

not

less

than

2

ohms

per

channe1.

Note

that

UNMUTED

MONitor

output

terminals

are

also

provded

within

the

console

to

drive

a lobby

speaker,

etc.

S-20 page 8

I

STEAM POWERED RADIO.COM

I

Speaker

leads

carry

high

currents

because

of

the

low

impedance

levels

of

the

speakers.

These

leads

should

be

routed

away

from program

output

wires,

and

especially

from

inputs.

6.0

MAINTENANCE

You

have

invested

a

considerable

sum

of

money

in

your

LPB

S-20

Dual

Stereo

Console.

It

is

a

high-qua!

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

baked epoxy

overspray

for

addJtlonal

protection.

Use

no

sol-

vents

on

the

pane1.

Detergent

c I

eaners

such

as

11

409"

are

qu

I

te

safe

and

satisfactory,

as

is

"Windex"

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

reconmended.

Quarterly,

we

reco11111end

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.

6.1

CIRCUIT

DIAGRAM

AND

PARTS

LIST

A

comp

1

ete

circuit

diagram

is

furn

lshed

with

this

manua

I.

Refer

to

it

for

details

of

switching

functions,

etc.

A

complete

parts

1

ist

tabulation

also

follows.

A

price

1

ist

for

re-

pla

cement

parts

is

impossible

to

publish

because

of

rapid

changes In

our

costs

from

suppliers.

LPB

will

be

pleased

to

quote

current

parts

costs

in

response

to

your

inquiry.

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

STEAM POWERED RADIO.COM

I

Figure

A

TEAC,

Sony,

CONNECTING

AN

UNBALANCED

HIGH

IMPEDANCE

AUDIO

SOURCE

etc.

-c

l

I~

600

High z ~

ohm

use sh1elded use t

wi

st

wire

-

here

wire

here

High Impedance

to

600

ohm

transformer,

such

as

UTC

0-1

ed

Figure

B-1

ACCOMODATING

HIGH-OUTPUT

HIGH-LEVEL

AUDIO

SOURCES

+4dBm

-+

R2

oo

DD

0 0

600&'2

balanced

Rl

Ampex

AG-600B

11

H

11

pad

attenuator

source

1eve

l,

dBm

dB

loss

R

l,

ohms

-7

3

51

-4

6

100

-1

9

150

+2

12

180

+5

15

200

+8

18

220

-lOdBm

-+

ba

l .

600&'2

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

LPB Signature II User manual

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