Dyna Dynakit sca-35 Installation instructions

SERIAL

NUMBER

. I

15350075

This

number

must

men-

tioned

all communica-

tions concerning Dynakit.

,..

Price

$1.00

STEREO

CONTROL

AMPLIFIER.

INSTRUCTIONS

FOR

ASSEMBLY

AND

OP.ERATION

Patented

086315

• •

••

SPECIFICATIONS

Inputs:

Outputs:

Controls:

Tone

Control

Range:

Sensitivity

for

Rated

Output:

Power

Output:

Frequency

Response:

Power

Response:

Distortion:

Hum

and

Noise:

Tube

Complement:

Silicon

Diodes:

Power

Consumption:

Special

Features:

7pairs:

RIAA

magnetic

phono

low level,

magnetic

phono high level (50,000

ohms);

Ceramic

phono;

NAB

71j2

i.p.s.

tape

head

(100,000

ohms);

radio, tape,

spare

(250,000

ohms)

Constant

level

tape

output,

and

16 ohm

loudspeaker

outputs,

center-channel

loudspeaker

output,

provision for

headphone

connection.

Selector, Volume, Balance, Bass,

Treble,

Stereo-Mono

Switch, Loudness

Compensation

Switch,

Filter

Switch, Power Switch.

±12

cps

and

15 kc.

2.5 mv

tape

head, 4mv

low level

magnetic

phono, 1volt

high level inputs.

watts

continuous, 45

watts

IHF

Music

Power

(both

channels).

±0.25

from 20 cps

20 kc.

20 cps

20 kc

without

exceeding 1%

distortion

within 1

of 17.5

watts

(each

channel)

Less

than

17.5

watts

(each

channel)

Less

than

0.2%

any

input

average

listening levels.

below

rated

output

low level inputs.

down

high

level inputs.

12AX7/ECC83

(2),

7199

(2),

6BQ5/EL-84/7189

(4).

500

MA,

1000

PIV

(2).

110 watts, 120 volts 60 cycle AC,

120/240volts

50/60

cycle

with

optional

PB-028

power transformer.

Attractive

Champagne-gold anodized

aluminum

front

panel

and

die-cast knobs; 2

convenience

outlets; provision for

headphone

output

center-channel level control;

center

speaker

output;

power

transformer

sealed

special

encapsulating

material

for coolest,

quietest

operation.

INSTRUCTIONS

FOR

ASSEMBLY

AND

OPERATION OF

THE

DYNAKIT

SCA-3S

STEREO

CONTROL AMPLIFIER

The

SCA-35

high

quality

stereo preamplifier

and

amplifier combination which serves

acontrol

center

for

various program sources

such

phonograph,

tape

and

radio.

The

SCA-35

permits

selection of

the

program

source

desired, modification of

the

tonal characteristics of

the

sound

source,

and

change

of volume;

provides

output

con-

nections for loudspeakers

and

headphones.

The

connection of various types of program sources

made on

the

back

panel

through

the

several sockets pro-

vided.

The

shielded

audio

cable'S

and

plugs

supplied

with

the program source

equipment

are

used

for connection be-

tween these components.

There

are

screw terminals for

connection of loudspeakers to

the

unit.

The

upper

row of

inputs

and

outputs

used

for

the

left channel,

and

the

bot-

tom row for

the

right

channel.

FRONT PANEL CONTROLS

The

front

panel

controls

have

been designed to

make

thf:

operation of

the

SCA-35 simple

and

obvious while pro-

viding

suitable

flexibility. Although

is possible to enjoy

use of

the

SCA-35 using

only

the

power

and

selector

switches

and

the

volume control, knowledge of

the

function

the

other

switches

and

controls

can

provide increased

listening pleasure.

Each

of these will be described briefly.

.Jeledor

Switch

•

Rotation

the

selector switch

the

marked

positions

permits

use of

the

marked

input

source. After switching to

"phono"

for example,

start

the

record player,

and

its

signal

will

available to you.

The

stereo-mono switch

beneath

the selector switch

extends

its

utility.

For

stereo signal sources, leave the

switch

the

"stereo"

position.

When

amono source is

being played,

the

"mono"

position of

the

switch brings

this

single channel signal

through

both

loudspeakers. When

playing monophonic recordings with astereo cartridge,

the

"mono"

position eHminates

most

the

vertical noise com-

ponents

of the signal.

When

astereo

tuner

tuned

amonophonic station,

the

"mono"

position of

the

switch

frequently eliminates noise

and

distortion.

Volume

Control

Clockwise rotation of

the

volume control increases

the

level of

the

signal

through

both

loudspeakers:

The

normal

setting

the

control will

depend

the

efficiency of

the

loudspeakers

and

the size of

the

signals from

the

cartridges

and/or

tuners.

should be recognized

that

the

position of

the

control is

not

related to

the

power level

which music

played-you

may

have awide range of settings to give

aspecific

sound

level.

Adjustment

should be

made

the

loudness level desired

without

regard

the

position of

the

knob pointer.

the

tuner,

other

input

equipment, has

its

own level

setting

volume control, this should be

set

that

when

...

witching from one

input

another,

the

sound is close to

same loudness.

Beneath

the

volume control is

the

loudness switch.

When

switched to

"loudness"

there

is additional bass intro-

duced

into

the music when

the

volume control is

the

mid-point

below.

high settings of

the

volume control,

the

loudness switch has no effect.

The

reason for this fea-

ture

that

the

human

ear

has decreased sensitivity to low

frequencies

low volume levels,

and

the

loudness switch

helps to correct for this.

will

add

afullness to low level

music which

can

enhance

its

pleasure.

Balance

Control

The

balance control is used to equalize

the

signals

the

two loudspeakers, which helps

center

the

sound.

Turning

the

balance control to

the

left will diminish

the

sound

the right speaker,

thus

making the sound source move to

the

left.

Turning

the

right

will move

the

sound source

the

right.

Normally

the

balance control is centered when

is in

the

mid-point

(12

o'clock),

but

differences

program-

ming,

speaker

efficiencies,

room acoustics,

and

com-

ponent

tolerance

the

SCA-35

may

require a

setting

off

the

mid-point. Since

the

effects of

this

control

are

very

gradual

the

area

of rotation from 9o'clock

3o'clock,

offsetting

this

region does

not

indicate abnormality.

When

rotated

either

extreme, the balance control cuts

off one

speaker

completely.

This

can

used

if different

signals

appear

the two stereo channels

(such

the

reverse

track

of amono

tape

machine),

and

the

two

are

not

wanted

simultaneously.

Tone

Controls

The

bass

and

treble controls

operate

similar fashion

with

the

treble control affecting high frequencies,

and

the

bass control

the

low frequencies.

Each

of these gives "flat"

response

without

frequency discrimination when

the

pointer

12 o'clock. Clockwise rotation provides boost,

and

counter-clockwise rotation gives

attenuation.

When

program

sources

are

harsh

strident, treble

atten-

uation will improve

the

sound.

there is boominess, bass

attenuation

should be used.

Some

thin sounding

material

can

benefit from bass boost.

These

controls should be

set

whatever position

sounds

best,

but

should be remembered

that

departures

from

"flat"

are

ofacorrective

nature;

and

the

user

should

not

get

the

habit

of listening to acorrected

tonal characteristic.

Beneath

the

tone controls is

the

filter switch. When

this

the

"filter" position

gives anarrow

band

response,

attenuating

both

high

and

low frequencies simultaneously.

This

should be

used

with poor program material,

such

scratchy

records, excessive rumble, noisy radio broadcasts,

and

so on.

attenuating

both

ends

the

spectrum,

does

not

create

ashift

overall tonal balance.

can

used

Conjunction with

the

tone controls for

great

extremes of tonal correction.

Power

Switch

The

power switch has

the

obvious function of turning

the

SCA-35

and

off (along with

any

equipment

the

switched

outlet

the

back

panel).

Allow

about

15 seconds

for

warmup

after

turning

this

switch to

"power."

BACK

PANEL

CONNECTIONS

Phono

Connections

Either

arecord

changer

aprofessional

type

turntable

can

be used.

There

are

three

pairs

phono

inputs,

allowing

for use of all

types

phonograph

cartridges.

There

choice of

(1)

low level

magnetic

cartridge,

(2)

high

level

magnetic

cartridge,

(3)

crystal

ceramic

type.

Most

pop-

ular

magnetic

cartridges

are

the

low level type. However,

the

cartridge

rated

than

20 millivolts

this

is a

high

level model,

and

the

high

level

magnetic

input

should

be used.

you

are

using

alow level

magnetic

cartridge

and

find

that

there

seems to

too

much

amplification when

using

the

low level

phono

input,

then

the

high

level

magnetic

input

may

be used.

This

will reduce

the

total

amplification

without

detriment

to performance. Always

read

instructions

which

accompany

the

cartridge

deter-

mine

whether

its

manufacturer

has

any

special recommen-

dations

for

its

connections

and

use.

many

the

turntables

and

record changers

made

today

there

is a

separate

ground wire.

This

should

be con-

nected

the

screw

the

back

panel

the

SCA-35 above

the

phono

inputs.

such

ground

wire is

not

supplied

with

yout

phonograph,

then

may

be necessary to

connect

wire,

addition

the

audio

signal cables from

the

car-

tridge, from a

ground

point

the

turntable

motor

arm

the

grounding screw

the

SCA-35.

Normally

not

desirable

make

further

ground

conections

water

pipes

"earth"

ground.

the

phono

cartridge

is amono one,

then

is suggested

that

you

COlUlcct

its

output

only

one

input

(either

chan-

nel).

you

want

hear

sound

through

both

channels,

turn

the

stereo-mono

switch

the

front

panel

its

mono posi-

tion

hear

the

program

through

both

loudspeakers.

Tape

Connections

The

SCA-35

can

used

either

with

tape

machine

which has

its

own

tape

amplifier, or

playback

electronics, or

with

tape

deck

having

direct

output

from

the

tape

head.

the

machine

has

tape

playback

amplifier,

then

the

out-

put

relatively

high

level.

this

case

this

output

connected to

the

input

the

SCA-35

marked

"From

TAPE

AMP."

the

machine

deck

only,

the

output

very

low

and

the

input

marked

"From

TAPE

HD"

used.

The

tape

head

input

has

very

high

amplification

and

the

required

NAB

i.p.s.

equalization

for

tape

head

playback.

Generally, when

the

tape

head

input

is used, a

ground

wire

must

connected

from aspecific

point

the

tape

deck

(see

instructions

supplied

with

tape

deck)

the

grounding

screw

the

SCA-35.

Try

with

and

without

this

ground

wire for lowest

hum.

the

tape

machine

has

arecording amplifier,

you

can

connect

the SCA-35

the

tape

machine

for recording from

the

phonograph

from

the

tuner.

The

high

level

input

the

tape

recorder

(not

the

microphone

input)

should

connected

the

socket

marked

"To

TAPE

RECORD."

Whatever

is being

played

through

the

SCA-35 will be re-

corded

unaffected

volume

and

tone

controls

the

SCA.

Thus

you

can

listen

program

and

adjust

volume

and

tone

controls

suit,

without

affecting

the

signal going

into

the recorder.

the

special case where

desired

play

multi-

track

tape

with

monophonic

recording

all

tracks

through

the

SCA-35,

the

track

recorded

the

opposite

direction

will

come

through

one

channel

the

SCA-35

unless

one

two

expedients

used

prevent

this:

(1)

One cable

can

removed

from

the

unwanted

chann*,

then

using

the

mono

position of

the

stereo-mono

swit~)

the

sound

will come

through

both

speakers,

(2)

The-

balance

control

can

turned

either

extreme

position to

eliminate

sound

through

the

unwanted

channel.

The

SCA-35

can

used

for

playing

recorded

tape,

but

cannot

used

for recording

with

tape

deck which

has

recording preamplifier.

Radio

Connections

Radio

tuners

which

can

supply

one

volt

audio

output

can

used

with

the

SCA-35.

the

tuncr

stereophonic,

then

its

left

output

is COlmected

the

upper

radio

input

and

the

right

output

goes

the

lower

radio

input

the

SCA-35.

the

tuncr

is monophonic,

can

connected

either

with a

"Y"

connector

both

radio

inputs,

only

one

input.

one

input

is used,

you

will have

turn

the

stereo-mono

switch

the

mono

position to receive

sound

from

both

speakers.

the

tuner

has

separate

outputs

for

and

with-

out

its

own provision for switching these,

you

may

use

one

(or

both)

of the

radio

inputs

for

and

the

spare

inputs

for

AM.

Then

selection of

broadcasts

can

made

with

the

selector switch

the

SCA-35.

Additional

Inputs

The

spare

input

the

SCA-35 will

accommodate

any

type

high

level

input

source which provides

one

volt

audio

signal. Asecond

tape

machine

(having

play-

back

electronics huilt

in)

tuner

may

used

this

inpue

second

phonograph

which

includes

its

own preamplifier.

Loudspeakers

The

SCA-35

can

provide

sufficient power to

drive

all

but

the

most

inefficient

loudspeaker

systems.

Check

the

specifi-

cations

the

loudspeaker

determine

its

impedance.

Generally

this

will be 8

16 ohms.

The

speaker

terminals

the

SCA-35

are

marked

for

speakers

these

values,

but

these

terminals

will

accommodate

awider range of imped-

ances

than

marked.

For

example,

the

ohm

output

can

used

for

speakers

of 4to 11 ohm ratings;

the

ohm

output

can

used

with

speakers

from 12

20 ohms.

The

left

channel

loudspeaker

should

connected

to the

upper

output

strip. A

pair

of wires,

such

#18

lamp

cord,

should

used

with

one

wire going to

the

common

terminal

(marked

HC")

and

the

other

the

ohm

terminal.

The

right

speaker

should

similarly

connected

the

lower

output

strip.

Note

that

the

extreme

left

hand

screws

each

strip

are

connected

together

awire

strap.

either

the

two

speakers

should

connected

these

terminals. However,

is possible to

connect

athiJ:d loud-

speaker-as

center

remote

speaker--·to

these

terminals.

Details

this use

are

given later.

is also possible to

connect

headphones

to the

loudspeaker

terminals, a

subject

covered

detail

later.

any

music

system

best

that

both

loudspeakers

identical.

this

not

possible, the

stereo

effect

may

considerably

distorted,

and

there

will be shifting of

positicA'

sounds

between the

speakers

in away which is

unrelat~P'

the

correct

localization of those sounds.

CONNECTING

CENTER

LOUDSPEAKER

Ventilation

When

using

the

SCA-35

is essential

that

have ade-

quate

ventilation.

This

unit

dissipates 110

watts

of heat,

and

you

can

see

that

there

the

same

heating effect

with a110

watt

incandescent

lamp

asmall metal con-

tainer-the

case will get

quite

watm

to the touch,

and

should

have

air

space

above to

permit

the

heat

to dispell.

There

should

always be several inches of

air

space above the

unit

and

behind

it. Never

place

anything

directly

top

the

cover when

the

amplifier is operating.

Under

some conditions

is advantageous to be

able

use a

center

loudspeaker

which

handles

the

monophonic

signal

(sum

of left

and

right

channels) derived from

the

two

parts

the

stereophonic signal.

This

center

speaker

can

eliminate

the

"hol.e-in-the-middle" effect of

speakers

which

are

widely

separated.

The

composite

center

signal

can

also

used

with

aremote

loudspeaker

for monophonic

reproduction

another

area.

The

signal for

the

center.

speaker

is available

the

back

panel

the SCA-35 with-

out

need

for

another

amplifier.

Switch

the

stereo-mono switch to

"mono."

Then

adjust

the

balance

that

the sound

equal

from both loud-

speakers.

Stand

slightly forward of the speakers

equal

distance

from each. Move from side to side while

trying

to loeate

the

sound

source.

the

speakers

are

phased

correctly,

the

source will

the

center, when

you

are

the

center,

and

will

shift

smoothly to whichever

speaker

you

approach.

the

speakers

are

phased

incorrectly, there

will

abrupt

jump

the location of the sound,

and

will

shift

suddenly

from one side to the

other

with

little

apparent

centering.

correct

the

phasing

of the loudspeakers, if

is incor-

rect,

you

must

interchange

the two wires between the

SCA-35

and

one of the speakers.

This

can

done

either

the

amplifier

the speaker.

Cabinet

Mounting

The

oversize

front

panel

the SCA-35 facilitates cab-

inet

installations.

The

rubber

feet

are

not

used.

supporting

shelf

installed

flush with

the

bottom of a

31:;{o"

13Yto"

cutout

the

cabinet

panel is required.

3Y2"

square

ventilation

cutout

should

made

in the

shelf to coincide with

the

punched-out

section of

the

SCA

bottom

plate,

under

the

output

tubes. A

PBK

bracket

kit,

which eliminates

the

need for the shelf, is available directly

from

Dynaco

for $2.00.

C.O.D.'s please.

Adequate

ventilation

imperative.

The

warranty

does

not

cover

equipment

which

has

been

subject

to abuse as

the

result

of insufficient ventilation.

Cabinet

installations fre-

quently

require

the

use

small

circulating fan, particu-

larly

where

the

SCA

must

mounted

close to atuner,

where vertical (face

up)

mounting

is necessary.

Under

circumstances

should

the

SCA

be stacked immediately

above

below

the

Dynatuner.

USING

YOUR

SCA-35

Other

Back

Panel

Connections

There

are

two AC

outlets

the

back

panel to which the

wer cords of

auxiliary

equipment

may

be connected.

One

these

outlets

switched

unison

with

the

SCA-3S when

SCA's

power switch is operated.

The

other

outlet

not

switched

and

will

furnish

power

all times

that

the

SCA's

power cord is plugged in.

The

switched

outlet

may

used

to power aradio

tuner

that

this

can

turned

and

off

with

the

SCA-3S.

The

lUlswitched

outlet

should

used

for

turntable,

record changer,

tape

machine.

These

devices

require mechanical switching

and

should

not

be switched

automatically

when

the

SCA-35 is

turned

off.

The

line cord of

the

SCA-35

should

be plugged

into

suitable

outlet

furnishing

nominally

120 volts, 60 cps

alter-

nating

current

(120

240 volts, 50

60 cycles for

export

models) .

There

are

two

knurled

shafts

the

back

panel

which

are

used for

hum

adjustment

the

two channels.

Their

func-

tion is explained below.

Phasing

Loudspeakers

For

best stereo effect,

the

loudspeakers

should

be prop-

erly

phased-an

adjustment

which is

made

once

and

can

then

left fixed.

Phasing

consists of

arranging

the

polarity

{

the

speaker

connections so

that

both

speakers

function

unison, moving

the

same

direction

the

same

time,

monophonic signals.

Hum

Adjustments

Turn

the

volume down low,

set

the

selector switch on

"phono,"

and

turn

the

SCA

power switch. After the first

5seconds,

advance

the

volume control slowly

until

you

ear

some

hum

from the loudspeakers.

Then

turn

the

bal-

ance

control to

cutoff

the

right

loudspeaker,

and

adjust

the

left

hum

control

(on

the

back

panel)

for

minimum

hum.

Repeat

this

with

the

balance

control

set

cut

off the left

loudspeaker,

adjusting

the

right

channel

hum

control.

These

controls

should

give some

minimum

point

{or hum;

and

this

point

should

low enough to

inaudible

normal listening levels.

Turn

the

volume down,

place

arecord

the

turntable,

and

advance

the volume

until

you

have a

suitable

level;

then

you

can

adjust

balance

and

tone controls to

your

satisfaction.

The

same

setup

procedure

can

be followed

with

tape

deck, using

the

tape

head

input.

The

minimum

hum

point

will

about

the

same

point

with phono.

neither

phono

tape

head

inputs

are

to be used,

the

hum

level

will be

much

lower,

and

may

be difficult to

determine

where

the

minimum

settings

the

hum

controls fall.

this case, since

hum

should

be inaudible,

not

important

whether

the

controls

are

set

accurately.

Once

the

associated

equipment

is connected to

the

SCA-35

and

you

are

familiar

with

the

operation

the

con-

trols,

you

are

ready

try

out.

Lliiiiiiiiiliiiiiiililll

iiiiiiiiiiiiiil

SWITCH

CRAFT

TYPE

128

LEFT

RIGHT

SPEAKER

If,

after

the

headphones

are

installed,

found

that

the

right

and

left sides

are

incorrect

and

the

phones

are

not

of aconstruction which

can

be reversed

the

head,

this

can

most simply corrected

disconnecting

• I

resistors from

the

two

jack

lugs

and

interchanging

the

connections.

USING HEADPHONES WITH

THE

SCA-35

Headphones

made

for

high

fidelity usage

are

generally

the

low

impedance

type, designed

be connected

the

loudspeaker terminals of

the

amplifier.

These

can,

course, be

used

directly with

the

SCA-35

accordance

with

the

instructions of

the

headphone

manufacturer.

addition, for ease of

headphone

connection

and

use,

ahole for a

headphone

jack

is available on

the

back

panel

the

SCA-35. A

jack

the

Switchcraft

type

12B,

equivalent,

can

mounted

this

hole. A

type

290 plug,

equivalent, should be

used

with the 12B jack.

the

headphones

are

supplied with adifferent

type

of plug,

the

proper

jack

should

be obtained for

the

plug

used.

The

diagram

below shows

the

best

method

of connection

the

headphone

jack.

The

100 ohm, %watt, resistors

drop

the

signal

the

level which is required for head-

phones.

there

inadequate

level

after

installation, these

resistors

can

be reduced

47 ohms,

any

specific

value recommended

the

manufacturer

the

head-

phones. Some headphones have

the

resistors

built

in.

Then

not

necessary

install them,

and

straight

wires (insu-

lated

avoid

short

circuits) .should

connected

place

the

resistors shown.

is desired to

cut

out

the

loudspeakers completely

for

headphone

listening,

the

pictorial diagram shows how a

double pole switch

can

used

to eliminate sound from

the

loudspeakers

during

headphone

use.

This

switch

can

mounted

any

place along

the

loudspeaker wires so

that

can

kept

aconvenient place if switching is required

frequently. '\\

best

that

all

the

speakers should

identical types

when using

this

arrangement.

this is done,

the

sound

level

the

center

speaker

will be comparable with

that

the

stereo speakers.

The

volume control will reduce

the

level of

the

extra

speaker.

can

be used to reduce

the

level

of this

speaker

zero,

and

then

the

stereo speakers will

function

their

normal

way.

the

control is

not

added,

and

is desired

cut

out

the

center

speaker

to restore

normal

stereo operation, this

can

be done

re-installing

the

jumper

the

back

panel.

This

can

also

done

adding

aswitch to connect

together

the

two leads

the

center

loudspeaker.

This

switch

can

located

any

place which is convenient -

the

speaker

location,

the amplifier.

When

the

switch

is closed,

there

will be

sound from

the

center

speaker,

and

normal

stereo reproduction will

obtained.

The

center

speaker

should be

phased

properly.

This

can

be done

listening to

the

smoothness of

transition

sound

between speakers while moving back

and

forth

between them.

there

are

sudden

jumps

localization of

the

sound,

the

two wires to

the

center

speaker

should

interchanged. Correct phasing should provide asmooth

change

location of

sound

from side speakers to

center

speaker.

the

center

speaker

used

remotely, phasing is

not

important.

NOTE:

any

time

that

the

center

speaker

is removed,

the

jumper

between

the

screw terminals must be reinstated.

neither

the

jumper

nor

center

speaker

is connected,

the

resulting

sound

will have no monophonic components.

There

will be

sound

with monophonic sources

and

unrealistic effects with stereo sources.

CENTER

RIGHT

LEFT

SPEAKER

100fl,4W

....

-:..~--~~.

/---

....

CONTROl..

/;;':-'

,,~?®\!

,,//i'

v~-_ll::~~-~"'l

f/,

//";/

....

-',

//.,.

(~I'''

...

_-_

....

...

" /

CONTROL

M~Y

8£

MO/JNTEO

INSlbE

@I/

Ci/ASSISAS~N

REMOVEJUMPER

CEIITER

WHEII

CEIITER

SPEAKER

I.tJCA·

SPEAKER

CON·

TIOII,

IIECTEO

Connection of

the

center

speaker is accomplished by

removing

the

wire link,

jumper,

which connects

the

left-

most screws

the

two loudspeaker

terminal

strips

and

connecting

the

two wires from

the

extra

speaker

these

two screws.

The

diagram below also shows how avolume,

level setting, control

can

be optionally

added

to control

the

level of

the

center

speaker.

The

control itself is a 4 watt,

wirewound, potentiometer

rheostat.

They

are

available

all

radio

parts

supply

stores.

The

control for

the

center

speaker

can

be connected

the

back

panel

the

SCA

using

the

hole which is avail-

able,

can

connected

the

loudspeaker

location-

this

particularly

convenient for aremote speaker.

TECHNICAL DESCRIPTION

The

DYNA

Stereo Control Amplifier, SCA-35, is acom-

lete stereo preamplifier

and

stereo power amplifier com-

ed on asingle chassis with asingle power supply.

The

SCA-35 uses new

circuitry

and

new components in aunique

arrangement

which provides highest

quality

performance

ill

acompact

and

moderately priced unit. Superficial ex-

amination

the

circuit

the

SCA-35

might

indicate

apparently

simple

and

conventional design. However,

closer

scrutiny

will reveal

extremely sophisticated

and

carefully refined design.

There

are

four basic sections of

the

SCA-35:

(1)

the

stereo preamplifier; (2) the dQal tone control section;

(3)

the stereo power amplifiers,

and

(4)

the power supply.

Each

of these utilizes novel circuitry

with

premium grade com-

ponents conservatively operated.

The

four sections combine

inter-relationship which develops the maximum poten-

tial of these components.

The

Preamplifier

The

preamplifier section of

the

SCA-35

printed

cir-

cuit

module

which a12AX7

tube

used

for

each

stereo

channel. All low level

inputs

are

fed to

the

input

stages of

these tubes via aportion

the

selector switch.

High

and

low level magnetic cartridges

and

crystaVceramic cartridges

are

introduced to the

input

switch through a

PEC

(packaged electronic

circuit).

The

switch also selects a

tape

head

input.

These

low level signals

are

amplified

'through two stages

(the

two halves of

the

12AX7).

The

amplification of

this

tube

is increased almost to

its

theoreti-

cal

maximum

the

application of positive feedback from

cathode to cathode.

Anegative feedback loop containing

the

proper

equaliza-

tion circuits to

shape

the

response of phono

and

tape

head

is carried

around

the

12AX7. Operating

parameters

are

selected to enable this stage to

carry

signals

distortion

levels below 0.1

A 4 millivolt magnetic cartridge will

produce

one volt

1000

cps

the

output

of this section.

The

output

the

12AX7 is fed to

another

section of the

selector switch, which

this

point

can

also select higher

level

inputs

such

radio

and

tape

preamplifier.

The Tone Controls

Dual tone controls

are

used

anetwork' which is com-

pletely passive;

has

no distortion

noise.

This

network

is also a

PEC

which

all

components

are

encapsulated.

Associated with

the

tone controls

are

the

filter switch,

the

balance control,

and

the

volume control. Signal levels to

this section normally

are

about

one

volt (which is also the

normal

output

the

preamplifier

stage).

However,

the

design is such

that

signals of

any

magnitude

can

handled

without possibility of overloading the power amplifier

inputs.

Power

Amplifiers

Each

power amplifier is on its individual

printed

circuit

module.

These

are

truly

unique circuits

which optimum

use is

made

the

components.

The

first stage is apentode section of a7199 tube.

This

directly coupled to acathodyne

phase

inverter. Negative

feedback is

taken

from cathode to screen to stabilize

the

operating

point

this

pair. Apositive feedback loop

from cathode to

cathode

augments

the

amplification of the

stage.

The

cathodyne

inverter

has

the

unusual

advantage

that

its

phase

inversion capabilities

are

dependent

solely

the values of its associated resistors.

The

accuracy of phase

inversion is unaffected

tube aging

and

similar variations.

The

phase

inverter drives a

pair

of 6BQ5

output

tubes.

Careful investigation

has

determined

the

precise operating

parameters for

the

output

tubes

and

output

transformer.

The

output

transformer designed for the circuit

(DYNACO

Z-565) provides maximum linearity

this configuration.

This

transformer represents

advance in

the

state

the

art

permits

the full power of

the

output

tubes

handled

throughout

the

audio spectrum

unit

of very

small size.

also permits ahigh

order

of feedback with

complete stability of operation

under

all amplifier load

conditions.

Contrary

to traditional usage, asingle cathode resistor

used

for

all

four ou.tput tubes.

This

improves the per-

formance of

the

output

stage,

but

makes

desirable to

match

the

four

output

tubes.

The

output

tubes supplied

are

carefully

matched

for this circuit.

The

Power

Supply

The

SCA-35 is powered

apower transformer

and

full

wave rectifiers using silicon diodes.

Separate

heater

wind-

ings

are

included

the

power transformer to provide means

for individual

hum

adjustments

each

stereo channel.

The

power transformer is impregnated with

epoxy

resin which serves the

dual

purpose of

heat

dissipation

from

the

core

and

prevention of noise

and

vibration.

GENERAL

WIRING

PRACTICE

Assembly of the SCA-35 is exceptionally simple when

compared to

that

of other similar kits.

The

circuit boards

are

supplied with

all

components mounted,

and

the remain-

ing

parts

arranged

the chassis

open,

uncluttered

way

that

makes wiring quick

and

easy.

The

construction

the

SCA-35 should

take

no more

than

afew hours.

When

you

unpack

the

kit, check

the

components

against

the

parts

list

first. You

can

identify unfamiliar components

matching them to

parts

illustrated

the

pictorial

diagrams supplied.

Have

the

proper

tools

hand

before beginning to build

your

kit. You will need apencil-type soldering iron of 30-

to 60-watt rating; long-nosed pliers; diagonal cutters;

and

ascrewdriver.

you have asoldering gun,

should be

used

with care, especially when working

the

circuit board,

because of

its

higher

than

necessary

heat

output.

Although

not

essential, awire-cutting

and

stripping tool will help

considerably; these

are

available for less

than

adollar.

The

only

procedure involved

building a

Dynakit

which requires a

bit

of technique is soldering,

and

this is

quite

easy

master.

There

are

four steps to making agood

solder connection:

Make

agood mechanical connection.

Heat

both

parts

of the connection with

the

iron.

3. Apply solder to

the

connection

until

melts

and

runs.

Allow

the

connection to cool undisturbed.

WRONG

ALL

SOLDERING

MUST

DONE

WITH

ROSIN

CORE

SOLDER.

nection

almost

immediately.

Solder

should

then

applied

directly to

the

parts

to be soldered,

shown

the

middle

illustration

above,

and

both

iron

and

solder removed

soon

the

solder flows freely.

transfer

heat

from the iron to the wire

and

terminal,

the

tip

the

iron should be

kept

brightly

tinned

with

solder.

this is properly done

the

first time

the

iron

used,

the

tinning

may

maintained

wiping

the

tip with

acloth

sponge every few

minutes

while soldering.

When

correctly tinned,

the

tip

will

heat

both

parts

the

con-

The

circuit

boards of

the

SCA-35

are

supplied with all

components (resistors

and

cap;:lcitors)

already

mounted

and

soldered in place.

The

circuit boards

are

connected

the

other

sections of

the

amplifier channels

soldering

wires to eyelets on

the

boards.

These

eyelets, which

are

numbered for identification,

are

filled with solder already.

solder awire to them, first

"tin"

the

bared wire

heat-

ing

with

the

iron

and

flowing

solder

over it.

The

eyelet

then

heated

with

the

tip of

the

iron,

and

the

end

the

wire

inserted

soon

the

solder

the

eyelet

flows. A

correctly

made

connection looks like the illustration

right, above, which shows asmooth

transition

from

eyelet

to wire.

There

warranty

any

equipment

which acid

core solder

has

been used.

Make

sure

that

the

solder

you

use is

plainly

marked

"ROSIN

CORE."

not

use cheap

solder

solder of doubtful origin. Recommended solder

60/40

(60%

tin,

40%

lead)

rosin core.

Whenever one

(l)

wire is to be soldered to aconnection,

the

instructions will

indicate

this

the

symbol

(S).

When

two

(2)

wires

are

to be soldered to aconnection,

the

sym-

bol (S-2) is shown; when

three

(3)

wires

are

to be soldered,

the

symbol (S-3) appears, etc.

There

may

many

five

(5)

wires to be soldered to aconnection.

symbol

is shown, do

not

solder;

further

wiring will be

made

that

connection before soldering.

Components

can

be identified

comparison with

the

pictorial diagrams. Capacitors

are

individually marked.

Resistors will be

marked

either

with

their

values,

with

the

color code specified

the

instructions.

The

first color

nearest

the

end

the

resistor,

and

any

fourth color

band

may

be ignored.

number

steps

the

instructions begin,

"Connect

one

end

awire

...

", with

the

length

the

wire specified.

each case, first

cut

apiece of wire to

the

correct

length

from

the

roll

supplied

with

the

kit,

and

then

remove

about

%" of insulation from

each

end

before making

the

connec-

tion.

The

leads on components should be trimmed

they

are

used,

the

length chosen being

that

which permits acon-

nection to be

made

from

point

without

strain

terminals

components.

The

position of all wire

leads

should follow

that

shown

the

pictorial

diagram

closely

possible.

Care

must

be exercised to see

that

uninsulated

wires

not

touch

each

other,

and

cannot

through

vibration

sagging, unless, of course,

they

are

connected

the

same

point.

is especially

important

that

uninsu-

lated

wires

and

component

leads

terminals

not

touch

the

chassis

bottom

plate

accidentally.

Check

your

work

after

each

step,

and,

when

you

are

sat-

isfied

that

has

been

correctly done,

mark

the

space pro-

vided

and

go on

the

step.

Examine

the pictorial

diagrams often; if

you

check

your

work methodically,

your

amplifier should work

soon

the

wiring

complete.

One of

the

best

ways to

make

agood mechanical con-

nection is

bend

asmall hook

the

end

of awire,

and

then

crimp

this

hook

onto

the

terminal to be connected.

The

amount

of bare wire exposed

the

end

need

not

exactly

lit

-inch; however,

is too long,

there

danger

the

excess touching

another

terminal

the chassis.

There

need

wrap

the

wire

around

the

terminal more

than

one time,

this makes aconnection

that

much

difficult

remove if

error

has

been made.

fRONT

PANEL

MECHANICAL

ASSEMBLY

Place

the

front

panel

before

you

that

its

"wings"

are

facing you,

with

the

rectangular

switch

cutouts

the

bottom~

the

pictorial diagram.

Refer

the

pictorial

diagram

before

and

after

each

step

sure

that

you

are

proceeding correctly.

Install

the

pilot

light

socket

the

extreme left

end

the

panel

with a

screw

inserted

from

the

outside,

and

lockwasher

and

nut

from

the

inside

(the

side

the

panel

which

is toward

you).

The

screws

are

the

smallest

size

supplied

with

the

kit.

(v'>

Install

the

treble control

(marked

167504) next to

the

pilot

light (see

the

pictorial

diagram).

Place

%/f lockwasher on

the

shaft

before inserting

the

shaft

through

the

panel,

and

secure

with a%"

nut.

Before tightening

the

nut,

see

that

the

con-

necting lugs of

the

control

are

positioned

shown

the

diagram.

("""'"

Install

the

bass control (167205) in

the

next hole.

Place

a%" lockwasher

the

shaft,

insert

the

shaft,

and

secure

from

the

outside with a%/f

nut.

Be-

fore tightening

the

nut,

observe

the

orientation

the

connecting lugs shown on

the

pictorial diagram

and

see

that

the

bass control is positioned correctly.

(\A

InstaIl

the

balance control (167754)

the

hole

using %"

hardware

and

positioning

the

connecting

lugs

shown

the

pictorial diagram.

(v,

Install

the

volume control (177254)

the

hole

with

%" hardware, positioning

the

connecting lugs

..,.as shown

the

pictorial diagram.

I"}

The

power switch

the

only

one of

the

slide

switches

with

only

two connecting lugs.

Install

the

power switch from

the

inside,

the

rectangular

cut-

out

nearest

the

pilot

light socket so

that

its

connect-

ing lugs

are

the

position shown

the pictorial

diagram.

The

slide switch

mounting

holes

are

threaded

and

not

require lockwashers

and

nuts.

Install

the

power switch

with

two

screws in-

fierted

from

the

front side of

the

panel.

The

three

remaining slide switches

are

identical.

They

should

mounted

the

three rectangular

cutouts--their

orientation

not

important.

NOTE:

The

selector

switch

should

not

installed

until

later.

when

called

lor

the

instructions.

fRONT

PANEL

WIRING

These

instructions frequently specify

that

you

twist to-

gether some wires.

This

twisting should

not

be done too

tightly

the

wire

may

cut

through

the

insulation.

The

twist

sufficiently

tight

long

the

wires

are

neat

and

will remain together;

there

need

for excessive twisting.

Twist

together two

green wires.

Connect

one

end

of one wire to

pilot

light

socket lug # 1

(8).

Connect

the

same

end

the

other

wire to

pilot

light socket

lug

(8).

The

opposite

ends

of these wires will

.)ater

be connected to

the

main

chassis assembly.

Twist

together a

12%"

and

15/f

black wire so

that

they

are

even

one end.

Connect

one

the

match-

ing

ends

to power

switch

lug #

Connect

the

same

the

other

wire

power switch lug

#2.

3(""'f

Cut

each

lead

the

.02

mid

disc

capacitor

1;2/f.

Connect

one

lead

the

.02

mfd

disc capacitor

power

switch lug

(8-2).

Connect

the

other

lead

power switch

lug

(8-2).

The

numbering of

the

lugs

the

controls

shown

the

pictorial diagram.

Connect

one

end

of a

2Vz"

red

wire

treble control lug

(8).

Connect

the

other

end

to bass control lug

#5.

~Connect

one

end

of a21

12"

green wire to treble con-

trollug

(8).

Connect

the

other

end

to bass con-

trol lug

#2.

Connect one

end

of a

red

wire to bass control

lug

#5. Connect

the

other

end

to balance control

lug

#6(8).

7( ...,--connect one

end

of a

green wire to bass control

lug

#2.

Connect

the

other

end

balance control

lug

(8).

8(..-)

Twist

together a

black

and

5/f

red

wire. Con-

nect

one

end

the

black wire to

balance

control lug

Connect

the

same

end

the

red

wire to balance

control

lug

(8).

~bserve,

the

pictorial diagram, the

manner

which

the

PEC-555002 tone control modules

are

wired to

the

bass, treble,

and

volume controls. Begin

carefully Gutting

the

leads of

one

the

circuit

modules exactly to

the

following lengths; slip black

insulating sleeving on the leads

specified.

The

PEC

modules should be connected while

their

final

position.

Lead

2/f

lo/i" of sleeving

2" 1%" of sleeving

Ph/f

of sleeving

1%"

of sleeving

1114"

of sleeving

NOT

CUT

3%"

of sleeving

The

PEC

modules

should

be connected

shown

the

picture.

Place

the

first module flat

against

the

bass control so

that

the

numbers

marked

are

visible; this

module

connects to

terminals

nearest

the

front panel. After

all

connections

are

made

the

first module,

the

second module will be placed

flat

against

the

same position,

and

its

leads

connected to

the

terminals

the

rear

sections of

the

controls.

The

complete assembly should look

the

diagram.

10(

..,

Connect

PEC

lead

treble control lug

(8).

11("")

Connect

PEC

lead

to treble control lug

(8).

12(

"'1'

Connect

PEC

lead

to bass control lug

(8).

13(

-?l

Connect

PEC

lead

to bass control lug

(8-3).

14(

Connect

PEC

lead

to bass control lug

(8).

15(

~onnect

PEC

lead

to balance control lug

#4.

16(...-r

Connect

PEC

lead

to volume control lug

(8).

(V)

The

remaining PEC-555002 will now

connected.

First, carefully

cut

its

leads exactly to

the

following

lengths

and

slip

the

specified lengths of black insu-

lating

sleeving on

the

leads which require it.

Lead

of sleeving

10/0" !

7/s"

sleeving required

IVz

NOT

CUT

3%"

of sleeving

-9

Connect

PEC

lead

# 1 to treble control lug # 1

(S).

19 (

'1'

Connect

PEC

lead

to treble control

lug

(S).

20(

Connect

PEC

lead

# 3 to bass control lug # 1

(S).

Connect

PEC

lead

to bass control lug

(S-3).

22(..{

Connect

PEC

lead

bass control

lug

(.8).

23(,,1)

Connect

PEC

lead

to balance control lug

#3.

24(~

Connect

PEC

lead

to volume control lug

(S).

25(

v('Connect

one

lead

of a10

capacitor

to filter switch

lug

#1.

Connect

other

lead to filter switch

lug

#2.

26(

~Connect

one

lead

the

other

capacitor

filter switch lug

#4.

Connect

the

other

lead to filter

switch lug #5.

27 (

Connect one

lead

of a3.3

capacitor

to filter switch

lug

(S).

Connect

the

other

lead to balance con-

trollug

#4.

(0'

Connect one

lead

another

3.3

capacitor

to filter

switch lug

(S).

Connect

the

other

lead to bal-

ance

control lug

#3.

29(

Connect one

end

of a

6%"

green wire to filter switch

lug

(S-2).

Connect

the

other

end

to volume

control lug

(S).

30(~nnect

one

end

of a

6%"

red

wire

filter switch

lug

(S-2).

Connect

the

other

end

to volume con-

trol lug

(S).

31 (

Connect

one

end

12'"

green wire to filter

switch lug

(S-2).

Conn'ect

the

other

end

stereo-mono switch lug

#4.

Note

the

manner

which this

lead

is positioned

the

diagram.

32(v)Connect one

end

of a

red

wire to filter switch lug

(S-2).

Connect

the

other

end

to stereo-mono

switch lug

#5,

positioning this lead above

the

switches

shown

the

pictorial diagratp..

(~wist

together

green

and

black wire. Con-

nect

one

end

the

black wire to balance control-lug

#3.

Connect

the

same

end

the

green wire

bal-

ance

control lug

(S).

34(

~onnect

one

end

of a

3Vz"

black wire

balance

control lug

(S-4).

Connect

the

other

end

vol-

ume

control

lug

35(vr-Connect

one

end

of a 31

/2"black wire to balance

control

lug

(S-4).

Connect

the

other

end

volume control lug

#4.

36(

~nnect

one lead of

18,000

ohm

(brown-gray-

orange) resistor to loudness switch lug

#1.

Connect

the

other

lead to volume control lug

(S-2).

37(~

Connect

one

lead

the

other

18,000

ohm

(brown-

gray-orange) resistor

loudness switch lug

#4.

9'>nnect

other

lead

to volume control

lug

# 1

(S-2).

38(

..,..

Connect one

lead

of a22

tubular

capacitor

loudness switch

lug

(S-2).

Connect the

other

lead

volume control lug #

- .

39M

Cut

one

lead

the

other

capacitor

I".

Place

a%" piece of insulating sleeving

this lead

and

connect

to loudness switch lug

(S-2).

Con-

nect

the

other

lead

to volume control lug

#7.

40(

~onnect

one

end

of a

red

wire to loudness switch

lug

(S).

Connect

the

other

end

to volume

control lug

(S-2).

(~Connect

one

end

of a21

12"

green wire to loudnes

switch lug

(S).

Connect

the

other

end

...;rme control lug

(S-2).

42(

1'5

Connect

one

lead of a10,000

ohm

(brown-black-

orange) resistor to stereo-mono switch lug

#1.

Con-

nect

other

lead to stereo-mono switch lug

(S-2).

43 (0'Connect one lead of the

other

10,000

ohm

(brown-

black-orange) resistor to stereo-mono switch

lug

Connect

the

other

lead

to stereo-mono switch

lug

(S-2).

(....f

Connect

one

end

of a

green wire to stereo-mono

switch lug

(S-2).

45(v1"Connect

one

end

of a

red wire to stereo-mono

switch lug

(S-2).

This

completes

the

front panel sub-assembly.

Every

con-

nection

the

front

panel

shoulld have been soldered;

check to see

that

this has been done

The

hole in

the

front

panel which is still

empty

will

later

be filled by

the

selector

switch.

Set

aside

the

front

panel

sub-assembly for the

present

time.

REAR

PANEL

MECHANICAL

ASSEMBLY

(.I)

Place

the

rear

panel

that

its

"wings" face you.

Four

identical

input

socket strips

are

supplied,

each

with

four

input

sockets on it.

Mount

one of these

each

the

cutouts

shown

the

pictorial

diagram; -ihese

strips

are

mounted

from

the

inside.

Use a

screw,

inserted

from

the

outside, alock-

washer

and

nut\

for

each

mounting hole.

NOTE:

When

mounting

the

two

strips

the

two large cut-

outs,

center

the

strips

that

the

metal

portions do

.J)Ot touch

the

chassis.

There

are

two identical

output

terminal strips,

each

with

four screw terminals.

Mount

one

of these

each of

the

two

cutouts

provided

the

locations

shown

the

pictorial qiagram; these

strips

mount

from

the

outside.

sure

mount

the

ground lug

over

the

screw

the

place

indicated

the

pictorial

diagram

instead

of alockwasher.

Use

hardware

7each hole.

3(V"fThere

are

two AC convenience outlets.

Mount

one

of these

each of

the

cutouts

provided,

shown

the

pictorial diagram.

The

outlets

mount

from

the

inside. Use

hardware.

(~ount

the

fuse holder.

The

rubber

washer provided

should

be fitted

against

the

shoulder of

the

fuse

holder

before

is inserted

its

hole, from

the

out-

side

the

panel. While pressing

the

fuse holder

against

the

panel,

use

the

special

circular

nut

fasten

,in

place.

Note

position of connecting

lug B. .

.,.-

5(vJ

I~>the

rubber

grommet for

the

line cord in

its

~he

two

hum

controls

are

"snap-in"

types. Observe

the

position of

the

locating lug on each control which

fits ahole

the

chassis.

Snap

them

place

pressing

them

firmly

into

the

mounting

holes on the

panel

from

the

inside.

REAR

PANEL

WIRING

~There

are

atotal of sixteen

input

sockets on

the

rear

panel; the

center

(long) lug of each socket

has

number, shown

the

pictorial diagram. Connect

one

end

of a

1112"

black wire

the

pair

of short

lugs between sockets

and

#2.

Connect

the

other

end

the

pair

of short lugs between sockets

and

(8).

Connect

another

12"

black wire to

the

short lugs

between

and

(8).

Connect

the

other

end

the

short lugs between

and

#8.

Connect

another

1112"

black wire to

the

short lugs

between

and

#10,

and

the

other

end

the

short

lugs between

#11

and

#12

(8).

Connect

one

11;2"

black wire to

the

short lugs

between

#13

and

#14

(8);

and

the

other

end

}he

short lugs between #15

and

16.

tI)

Connect

one

end

of a

11;2"

black wire to

the

short

lugs between

and

(8-2).

Connect

the

other

end

the

short lugs between

#15

and

#16.

0'Connect

one

end

of a

2%"

black wire to

the

short

lugs between #15

and

#16

(8-3).

The

other

end

remains free for

the

present

time.

7( L?"Note

the

method

of connecting

the

PEC-555003

input

circuit module to

the

long lugs of sockets #1,

#2,

and

#4,

and

the

short lugs between

sockets

and

#2.

Connect

lead 1to socket

lead

0to

the

short lugs between # 1

and

#2,

lead

2to socket

#2,

lead 3

socket

(8),

and

lead 4to socket

(8).

~(.4'Connect

the

other

PEC-555003

input

circuit

module

the

following lugs: lead 1to socket

#9,

lead 0

the

short lugs between

and

#10,

lead

2to

socket #10,

lead

3to socket #11

(8),

and

lead 4

to socket #12

(8).

length of flat, 4-conductor cable

has

been 'sup-

plied

with

the

kit.

Cut

the

cable

into

two pieces,

one 10" long

and

the

other

12"

long.

Carefully

sepa-

rate

the

four wires

each

end

of each piece for

about

11;2",

and

strip

If.t'' of insulation from all 16

ends. Connect

one

end

the

!O"

piece to

the

long

lugs of

the

input

sockets in

the

following

manner:

Brown to socket # 5

(8).

Red

socket

(8).

Orange

socket

# 7

(8).

Yellow

socket

(8).

The

opposite

ends

are

not

to be connected

until

)pter.

10(!""')

Connect

one

end

the

12" piece of flat cable to

the

long lugs of

the

input

sockets

follows:

Brown to socket #13

(8).

Red

to socket

#14

(8).

Orange to socket #15

(8).

Yellow

socket

#16

(8).

The

opposite

ends

are

not

be connected

until

later.

Connect one

end

of a101;2"

red

wire

lug''''#10

(8-2).

Bend

the

free

end

this

wire to

mark

that

can

be identified

later

when

is twisted to-

gether

with

other

wires.

i.2(~

Connect

end

of a

101;2"

red

wire to

lug

(8-2).

13 (vt'

Connect

one

end

of a

12"

black

wire to

the

pair

short lugs between sockets

and

#10

(8-3).

Twist

this

wire together with

the

two

red

wires con-

nected

lugs

and

#10.

14(~onnect

one

end

8%"

green wire

lug

(8-2).

Bend

the

free

end

this

wire

mark

it.

15(~

Connect

one

end

8112"

green wire

lug

Y:;-2).

16(

Connect one

end

%" black wire to

the

pair

of short lugs between sockets # 1

and

# 2

(8-3).

Twist

this

wire

together

with

the

green wires con-

nected

lugs

and

#2.

(..-1'

The

lugs

the

rear

the

output

screw

terminal

strips

are

numbered

from # 1 to #8,

shown

the

pictorial

diagram~onnect

one

end

of al,,%"

bare wire

the

ground lug on

the

mounting

screw

the

upper

output

terrpinal strip.

Connect

the

other

end

output

lug

ff8. '

(wi.!

Connect one

end

of a

black wire to

the

ground

lug

the

mounting

screw of

the

upper

output

ter-

minal

strip

(8-2).

(

,;(Connect

one

end

of a

bare wire to

output

lug

(8).

Feed

the

other

end

the

wire

through

the

hole

output

lug

(8)

and

connect

output

lug

(8).

the

outside of

the

back

panel

connect

apiece of bare wire across

the

two screw

terminals

which correspond to

and

output

lugs.

(The

amplifier will furnish asignal

aderived

center

channel

speaker

this

wire is removed

and

aloud-

speaker

connected

its place.

Instructions

for

this

connection

are

covered

another

section.)

20(/(

Connect one

end

of a

Ph"

black wire to lug

outlet

A. Connect

the

other

end

to lug

outlet

(0'Connect one

end

black wire to lug

outlet

Connect

the

other

end

terminal

the

fuse holder

(8).

22(

.....,

Connect

one

end

of a

black wire to lug

the

left

hum

control

(8).

Connect

the

other

end

lug

the

right

hum

control.

23 (

~onnect

one

end

of a

10"

black wire to lug

the

right

hum

control

(8-2).

(6Twist

together two 11" green wires. Connect one

end

of one green wire to lug

the

left hum

control

(8).

Connect

the

same

end

the

other

wire

to lug

the

left

hum

control

(8).

(v(Twist

together two 11" green wires.

Connect

one

end

of one green wire

lug # 1 of

the

right

hum

control

(8).

Connect

the

same

end

the

other

wire

to lug

the

right

hum

control

(8).

26( )

Insert

asheet-metal screw

the

hole

marked

"GRND"

above

the

input

sockets, from

the

outside

the

chassis.

This

will furnish aconnection

point

for

external

ground wire when installing

the

amplifier.

This

completes

the

first portion of work on

the

rear

panel sub-assembly.

Note

that

there

are

several non-

soldered connections.

8et

aside

this

assembly for

the

present.

MAIN

CHASSIS

MECHANICAL

ASSEMBLY

(~ss

the

leads of one of

the

output

transformers

Z-565 through

the

two holes provided

nearest

the

front of

the

chassis (see

the

pictorial

diagram

for

the

correct

location).

The

leads of

the

transformer

are

two groups:

the

orange, black,

and

yellow

leads which pass

through

the

rear

chassis hole;

and

five

other

leads which

pass

through

the

front hole.

Before

attaching

the

transformer

the

chassis with

four

sets

hardware

(the

largest

size

supplied

with

the

kit),

mount

a5-lug terminal

strip

and

the

cable clamp

under

two of

the

transformer

mounting

screws

indicated

the

pictorial diagram.

Insert

the

lockwasher between

the

nut

and

cable clamp,

and

between

the

nut

and

terminal

strip

mounting

lug,

and

under

all

the

other

nuts.

not

tighten

the

nut

under

the

cable clamp.

2(V)

Pass

the

leads of

the

power transformer PA-774

through

the

two holes provided

the

rear

corner

the

chassis, observing

the

lead

orientation

shown

the

pictorial diagram.

Mount

the

transformer

with

hardware,

and

install

a5-lug terminal

strip

one

the

mounting

screws

shown

the

diagram.

NOTE:

Instructions

for

PB-028. a120/240

volt

transformer

for

use

outside

the

United

States.

will

found

the

end

the

regular

assembly

instructions.

3(....-)Use

hardware

mount

the

other

Z-565

output

transformer

the

rear

of the chassis,

the

posi-

tion

indicated

the

pictorial diagram.

The

orange,

black

and

yellow leads should pass through

the

holE!

closest to

the

rear

the

chassis,

and

the

remaining

~ds

through

the

other

hole. .

4(V)

Before

mounting

the

two

PC-lO

circuit

boards in-

stall

the

four

sockets

supplied

for V-5, V-6, V

-7

V-8

the

top

the

boards

(the

side on which

the

components

are

mounted).

Note

that

the

pairs

sockets

each

board

not

face

the

same

direc-

tion. Refer to

the

pictorial for

the

correct orienta-

tion.

Use

hardware;

insert

the

screws from

the

bottom

the

circuit

board

and

install

the

lock-

washer

and

nut

from

the

top.

(~Mount

the

two

PC-lO

circuit

boards from

the

bottom

the

chassis,

shown

the

pictorial dia-

gram,

using

four

sets

hardware

mount

each

board.

Note

their

orientation,

and

leave

air

space

~ween

the

boards.

6tv"'5

Mount

the

PC-11 preamplifier

circuit

board

the

position shown

the

pictorial diagram, using

hardware, from

the

bottom

the

chassis.

v5"

Install

the

two filter

capacitor

mounting wafers from

the

bottom of

the

chassis

the

cutouts

provided

the

rear

corner, using two sets of # 4

hardware

secure

each

wafer.

(1,1'

The

four-section filter

capacitor

(marked

60/40/20/

1(0)

mounts

the wafer

nearest

the

center

the

chassis; note

the

position of the symbols

stamped

the

underside

.of

the

capacitor,

shown

the

pictorial diagram.

The

capacitor

must

mounted

this

position.

Insert

the

mounting

lugs

the slots

provided, from

the

top of

the

chassis; check

the

diagram

'see

that

the

markings

are

correctly

located.

Then,

twist

each

the

mounting

lugs

%-turn

with

pliers, while holding

the

capacitor

firmly

against

the

wafer from above.

~The

same procedure

the

preceding

step

used

to install

the

two-section filter

capacitor

(marked

50/50)

the

remaining wafer.

Note

that·

the

symbols

stamped

the

underside

the

capacitor

are

differently positioned

than

for

the

other

filte

capacitor.

Mount

the

two-section filter

capacitor

inserting

and

twisting

its

mounting

lugs.

MAIN

CHASSIS

WIRING

The

leads of

the

transformers

may

often be somewhat

longer

than

is necessary to

make

the

connections required

with

proper

lead

positioning. In

each

case where atrans-

former

lead

is to be connected, first

run

the

lead to

its

connection point, following

the

path

shown

the

pictorial

diagram. After

cutting

the

proper

length of

the

lead,

strip

the

insulation

from

the

end

the

lead,

and

"tin"

the

end

heating

and

applying

solder to it; this pre-

vents fraying

strands

and

ensures

amore secure mechani-

cal bond before soldering.

..('

Connect

the

red

lead from

the

rear

output

trans-

former to

lug

(square

symbol) of

the

four-

section filter capacitor.

See

pictorial for wire

position.

2 (

Connect

the

red

lead

from

the

front

output

trans-

former to lug

(square

symbol) of

the

four-

section filter capacitor.

See

pictorial for wire

"'position.

(V'J

Twist

together

the

blue-and-white

and

green-and-

white leads from

the

output

transformer

nearest

the

front

the

chassis. Connect

the

blue-and-white lead

of V-7

(S).

Connect

the

green-and-white

lead

of V-7

(S).

4 (

~Twist

together

the

blue

and

green leads from

the

output

transformer

nearest

the

front of

the

chassis. Connect

the

blue lead to

N-

(S).

Connect

the

green

lead

V-B.

(V"')

Twist

together

the

blue-and-white

and

green-and-

white leads from

the

output

transformer

nearest

the

rear of

the

chassis.

Connect

the

blue-and-

white

lead

of V-5

(S).

Connect

the

green-

and-white lead to

of V-5

(S).

6( vf

Twist

together

the

blue

and

green

leads

the

out-

put

transformer nearest to

the

rear of

the

chassis.

Connect

the

blue

lead

of V-6

(S).

Con-

nect

the

green

lead

of V-6.

7(vr--Twist

together

the

two red leads from

the

power

transformer

PA-774. Connect

either

one of

the

red

leads to

lug

of terminal

strip

TS-l.

~Connect

the-

other

red power transformer

lead

of terminal

strip

TS-l.

9 ( J.1""Connect

the

red-and-yellow power transformer lead

Jp-mounting

lug.:A

the

four-section filter capacitor.

10(0"Twist

together

the

brown

and

brown-and-white leads

from

the

power transformer.

Pass

the

leads

under

the

cable clamp,

and

connect

the

brown lead to

lug # 1 of terminal

strip

TS-2.

Connect

the

brown-

and-white

lead

lug

of TS-2.

NOTE:

These

transformer leads

should

inserted

into

the

eyelet

that

holds

the

terminal to

the

strip,

thereby

providing

space

the

lug

for

the

other

wires

connected.

(prTwist

together

the

green

and

green-and-white leads

from

the

power transformer.

Pass

these leads

unde

the

cable clamp,

and

connect

the

green

lead

to lug

O~Cl

.~~~.

terminal

strip

TS-2.

Connect

the

green-and-

white

lead

to lug

of TS-2.

NOTE:

These

transfonner

leads

should

inserted

into

the

eyelet

that

holds

the

tenninal

the

strip,

thereby

providing

space

the

lug for

the

other

wires

be connected.

(nhe

silicon rectifier diodes

supplied

with

the

kit

may

any

the

three

types

shown

the

illustration;

although

different

appearance,

they

are

electrically

equivalent. Con-

nect

the

cathode

(or

plus)

lead

one

the

rectifier diodes

lug

terminal

strip

TS-l.

Connect

the

other

lead

the

diode

lug

terminal

strip

TS-1

(S-2).

IMPORTANT:

Arrange

the

diode

leads

exactly

shown

the

pictorial diagram.

When

soldering,

hold

pliers

the

lead

between

the

diode

body

and

the

solder

connection to avoid

application

of exces-

sive

heat

the

diode.

13(""""Connect

the

cathode

(or

plus)

lead

the

second

diode to

lug

terminal

strip

TS-l.

Connect

the

other

lead

lug

terminal

strip

TS-l

(S-2).

14("""-Connect

one

end

red

wire to

lug

# 2 of

the

terminal

strip

TS-1

(S-3).

Use

caution

avoid

excessive

heating

the

diodes.

Connect

the

other

end

lug

(semi-circle

symbol)

the

four-

section filter capacitor.

Connect

one

lead

the

50 ohm, 5

watt

resistor to

lug

(semi-circle

symbol)

the

four-section filter

capacitor

(S-2).

Connect

the

other

lead

lug

(square

symbol)

the

same

capacitor.

~6(

v1"'Connect

one

lead

of a2200

ohm

(red-red-red)

watt

resistor

to lug

(square

symbol)

the

four-

section filter

capacitor

(S-4).

Connect

the

othef..lead

lug

(triangle

symbol)

the

same

capacitor.

(Vf

Connect

one

lead

the

other

2200

ohm

(red-red-

red)

watt

resistor

lug

(triangle

symbol)

the

four-section filter

capacitor

(S-2).

Connect

the

other

lead

lug

(semi-circle

symbol)

the

two-section filter capacitor.

~~onnect

one

end

of a61!z" red wire

lug

-====

(semi-circle

symbol)

the

two-section filter capaci-

tor.

Connect

the

other

end

eyelet

the

rear

PC-lO

circuit

board

(S).

19(

~Connect

one

lead

of a22,000

ohm

(red-red-orange)

watt

resistor

lug

(semi-circle

symbol)

the

two-section filter

capacitor

(S-3).

Connect

the

other

lead

lug

# 1

(triangle

symbol)

the

same

capacitor.

20(

\1"'Connect

one

end

of a61!z"

red

wire

lug

(triangle

symbol)

the

two-section filter

capacitor

(S-2).

Connect

the

~ther

end

eyelet

#12

the

PC-l1

circuit

board

(S).

(0'Connect

one

lead

the

95 ohm, 5

watt

resistor

mounting

lug

Bof

the

four-section filter capacitor.

Connect

the

other

lead

lug

(no

symbol)

the

same

capacitor.

22(

"'fConnect

one

end

of a

black wire

mOlmting

lug Bof

the

four-section filter

capacitor

(S-2).

ton-

nect

the

other

end

mounting

lug Dof

the

two-

section filter

capacitor.

23(0

Connect

one

end

of a61!z"

black

wire

mounting

lug

Dof

the

two-section filter

capacitor

(S-2).

Con-

nect

the

other

end

eyelet

the

PC-ll

cir-

cuit

board

(S).

24(

v(Connect

one

end

of a

2Y2"

red

wire to

eyelet

the

rear

PC-lO

circuit

board

(S-2).

Note

one

wire

already

connected;

reheat

the

eyelet

and

insert

the

second

wire.

Connect

the

other

end

eyelet

the

front

PC-lO

circuit

board

(S).

25 (

V"'Connect

one

end

of a 41

black

wire to

mounting

lug

Cof

the

four-section filter

capacitor.

Connect

the

other

end

eyelet

the

rear

PC-lO

cir-

cuit

board

(S).

26(

W"'Connect

one

end

of a 61

/2"black wire

mounting

lug

Cof

the

four-section filter

capacitor

(S-2).

Con-

nect

the

other

end

eyelet

the

front

PC-lO

eircuit

board

(8).

27(

~onnect

one

end

11;4"

red

wire to

# 3 of

V-7

(8).

Connect

the

other

end

of V-8.

28(,0Connect

one

end

of a

21!z"

red

wire to

V-8

(8-2).

Connect

the

other

end

of V-6.

Co~p.ect

one

end

of a11

14"

red wire

# 3 of

V-6

(S-2).

Co~.he

other

encLt.9-Pin..#3 of-V-5,-

(VConnect

one

end

'of a

7."

red

wire

# 3 of V-5

(8-2).

Connect

the

other

.fmd

lug

(no

symbbl)

the

four-section filter capacitor.

(~Connect

one

end

of a11;4" green wire to

# 2 of

V-7 of

the

front

PC-lO

(S).

Connect

the

other

end

JP.

eyelet

(S).

32(~Connect

one

e~d

of a1Yt" green wire

of V-8 of

the

front

PC-lO

(S).

Connect

the

other

end

eyelet

(S).

33(

~Connect

one

end

a1Yt" green wire

# 2 of

V-5 of

the

rear

PC-lO

(S).

Connect

the

other

end

eyelet

(S).

34(

~onnect

one

end

of a 1J

14"

green wire

V-6 of

the

rear

PC-lO

(S).

Connect

the

other

end

eyelet

(S).

35(

'1""

Connect

one

end

of a 1

Y2"

green wire to

# 9 of

V-8 of

the

front

PC-lO

(S-2).

Connect

the

other

end

eyelet

(S).

36(....,..-connect

one

end

of a

Ph"

green wire to

# 9 of

V-6 of

the

rear

PC-lO

(S-2).

Connect

the

other

end

eyelet

(S).

37(

1>'Connect

one

end

of a41!z" green wire

eyelet

of front

PC-10

(S).

Connect

the

other

end

eyelet

#10

(S).

38(

~onnect

one

end

of a4Yz" green wire

eyelet

of rear

PC-lO

(S).

Connect

the

other

end

eyelet

#10

(S).

39(A'"

Twist

together

pair

black

and

green

wires,

each

long.

Connect

one

end

the

black wire to

eyelet

the

rear

PC-10

(S).

Connect

the

same-end

the

green wire

eyelet

the

rear

PC-10

(8).

Connect

the

other

end

the

black wire to

V-5.

Connect

the

remaining

end

the

green

wire

of V-5.

(V!.wist

together

pair

black

and

green wires,

each

2%"

long.

Connect

one

end

the

black wire

V-5

(S-2).

Connect

the

same-end of

the

green

wire

of V-5

(S-2).

Connect

the

other

end

the

black

wire

#5of V-6,

and

the

other

end

the

green

wire

V-G.

--------------

-----

(vf

Twist

together a

pair

of green

and

black wires,

each

2%"

long. Connect one

end

the

black wire to

lug

of terminal

strip

T8-2;

connect

the

other

end

of V-6

(8-2).

Connect one

end

of the

green wire to lug

of T8-2'. Connect

the

other

end

Jof

the

green wire to

of V-6

(8-2).

42(

Twist

together a

pair

of green

and

bla<;k

wires,

each

10%"

long. Connect one

end

the

black-wire to

eyelet

PC-11

(8).

Connect

the

same

end

the

green wire to

eyelet

#10

PC-ll

(8).

Connect

the

other

end

the

black wire to lug # 1 of

tenninal

strip

T8-2. Connect

the

other

end

the

green wire

jto lug

of T8-2.

43 (.,J)

Twist

together a

pair

of black

and

green wires, each

long.

Connect

one

end

of the black wire to

eyelet

the

front

PC-lO

(8).

Connect

the

same

end

the

green wire to

eyelet

the front PC-lO

(8).

Connect the

other

end

of the black wire to

# 5 of V

-7.

Connect the

other

end

the

green wire

j!!

of V-7.

44 (

V!wist

together a

pair

of black

and

green wires, each

2%"

long. Connect one

end

of the black wire

# 5 of V

-7

(8-2).

Connect

the

same

end

the

green

wire to

of V-7

(8-2).

Connect the

other

end

the

black wire to

# 5 of V-8,

and

the

other

end

the

green wire

#4of V

-8.

45(Vf'Twist

together a

pair

of green

and

black wires, each

long. Connect one

end

the

black wire to lug

tenninal

strip

T8-2. Connect the same

end

the

green wire

lug

of T8-2.

Connect

the

other

end

the

black wire to

of V-8

(8-2).

Con-

nect

the remaining

end

the

green wire

/!.f V-8

(8-2).

(1'>

Twist

together a

pair

of green

and

black wires each

12" long. Connect

one

end

the

black wire to eye-

let

#15

PC-11

(8).

Connect the

same

end

the

green wire to

eyelet

#13

PC-11

(8).

Connect

the

other

end

the

black wire to lug

tenninal

strip

T8-2.

Connect

the

remaining

end

the

green

wire

lug # 5 of T8-2.

WIRING

THE

PC-11 CIRCUIT BOARD

The

following wires

are

all

to be connected from

the

top

the

PC-11 preamplifier circuit board to

the

selector

switch.

make

the

wiring to

the

selector switch easier

when

done

later

the

assembly process,

the

wires

are

connected

the

circuit

board

now.

The

pictorial dia-

gram shows exactly which wires

are

connected

each

the

eyelets.

Insert

the

wires from the top,

and

solder

the

wires

place

heating

the

eyelets from below

the

board,

while

checkin~

the

eyelet

numbers to be

sure

that

they have

been

inserted

the

proper

eyelets.

\LENGTH

COLOR

EYELET

1%"

red

#16

2('£{

red

#17

2%"

red

#14

4(0

1%"

red

#19

5(a

red I

#20

5Hblack

#5.

7(~

1%"

green

8('

green

51,4" black

10(~

1%"

green

2%"

green

#11

12(

)

green

#7'

FINAL

ASSEMBLY

The

top of

the

selector switch

marked

with ared dot.

With

the

shaft pointing toward you,

and

the

dot

the

top,

alocating lug

protrudes

from

the

left front.

The

pictori

diagram shows the

tenninal

numbers,

and

identifies

wafers

(front)

and

(rear).

Whenever

terminal

location has separate lugs

the

front

and

back

the

wafer, be

sure

you

solder each wire to

both

lugs.

Connect one lead of a1.5 megohm (brown-green-

green) resistor to selector switch lug B-2. Connect

the

other

lead to lug B-5. .

(Y5

Connect one lead of a3.3

capacitor

selector

switch lug B-5

(8-2).

Connect

the

other

lead to

lug B-2.

(VConnec1

one

lead of

the'

other

1.5 megohm (brown-

green-green) resistor to selector switch lug A-2.

"connect

the

other

lead to lug A-5.

4(v'fConnect

one

lead

3.3

capacitor to selector

switch lug A-5

(8-2).

Connect

the

other

lead to

lug A-2.

5("-'r"Attach

the

front

panel

sub-assembly to the main

chassis with four

sheet

metal screws, using two

each

side

the

holes provided.

Note

that

all

but

the

two wires from

the

stereo-mono switch

pass

under

the

chassis.

6(\IfCarefully install the selector switch

the

front

panel

shown

the

pictorial diagram.

Place

%" lockwasher

the

bushing

the

front

the

switch,

insert

the

switch

the

hole providf'd

the

front

panel

and

rotate

that

the

red

dot

which

indicates

the

top of

the

switch

toward

the

top

the panel.

this position

the

locating lug

the

front of

the

switch should engage

the

small hole

the

front panel.

Fasten

the

switch securely

plac

with a

nut.

~Connect

the

red

wire from

eyelet

#16

the pc-n

circuit board to lug A-7

the

selector switch

(8).

Connect

the

red

wire from eyelet

#17

the

PC-11

circuit

board

lug A-9

the

selector switch

(8).

lI"I

Connect

the

red

wire 'from

eyelet

#19 to lug

>-J;.

(8).

lOvP0sition

the

black wire from

eyelet

over to

the

red

wire from

eyelet

#20

and

twist

them

together.

Position

the

twisted

pair

front of selector switch

wafer A(between the wafer

and

the front flange of

the

main

chassis).

Connect

the

red

wire to lug A-4

(8).

Connect

the

black wire to lug A-3

(8).

(~onnect

the

red

wire from

eyelet

#14

to lug

A-2

(8-3).

Connect

the

green wire from eyelet #8to lug

B-7

(8).

13(lIIf

Connect

the green wire from

eyelet

#7to lug

B-9

(8).

14(

Connect

the

green wire from

eyelet

lug?

fi-6

(8).

15(

"'1'

Position

the

black wire from

eyelet

lover

the

green wire from

eyelet

and

twist them together.

Position

the

twisted

pair

front of selector switch

wafer B(between wafers B

and

but

B).

Connect

the

green wire to lug B-4

(8).

Connect

the

black wire to B-3

(8).

C,j)

Connect

the

green wire from

eyelet

#11 to

B-2

(8-3).

(\l'.Connect

the

red wire from

the

stereo-mono switch •

to lug

A-l.

18(y(Connect

the green wire from

the

stereo-mono switch

lug

B-lo

(

Connect

the

black wire of

the

red-and-black twisted

pair

from

the

balance

control to eyelet

the

,'.

front

PC-10

(8-2).

This

the

second wire con-

.nected to this eyelet. Connect

the

red

wire of

this

pair

to eyelet

(8).

20(

Connect

the

black wire of

the

green-and-black

twisted

pair

from

the

balance control

eyelet

the

rear

PC-10

(8-2).

This

the

second wire

.connected to

this

eyelet. Connect

the

green wire of

.)his

pair

eyelet

(8).

(

""'Feed

the

twisted

pair

of green wires from

the

pilot

light socket through

the

cable clamp. Connect one

of these wires to

lug

of terminal

strip

-'1'8-2.

...£onnect

the

other

green wire to lug

of TS-2.

22 (

"1'"

Place

the

main

chassis

upside

down so

that

the

front

panel faces you. Bring

the

rear

panel sub-assembly

the

proper

position (also upside

down),

but

not

fasten in place

this

time. Position

the

flat

four

conductor

cables

and

the

twisted three sets of

wires from

the

input

sockets

the

top side of

the

chassis. All

the

other

wires will be connected

the

~tom

the

chassis.

(~~nnect

the

black wire from the

ground

lugs

between

input

sockets #15

and

#16 to

mounting

lug Aof the four-section filter

capacitor

(8-2).

(Y1'"

Connect the black wire from

the

ground lug

the

output

terminal

strip

mounting

screw

lug

terminal

strip

T8-l

(8).

25(

"'~onnect

one of

the

black power transformer

(PA-

y774) leads to lug

outlet

(8-2).

Connect

the

other

black power transformer

lead

to lug A

the

fuse holder

(8).

NOTE:

u.inl<

the

120/240

volt

power

transformer,

PB-028.

replace

this

steP

with

the

steps

specified

Page

16.

26(A

Connect the longer black wire of

the

pair

from

the

power switch to lug # 1 of

outlet

Connect

the

other

black wire of this

pair

to lug

outlet

(8-2).

Position these twisted wires

under

the

;;able

clamp.

(\-("Cut

the

black, orange

and

yellow leads from

the

out-

put

transformer Z-565

nearest

the

rear of

the

chassis to

3/1

each.

Twist

these together

and

connect

the

black

lead

output

lug

#8.

Connect

the

orange

lead

lug

(8).

Connect

the

yellow

lead

Jug #1.

28 (

'ItI'f

Connect

one

end

of a71

12/1

green wire to

output

strip

lug # 1

(8·2).

Connect

the

other

end

this

wire

/to

eyelet

the

rear PC-lO

(8).

(./)

Twist

together

the

black, orange

and

yellow leads

from

the

output

transformer

nearest

the

front

the

chassis.

Place

these leads

under

the

cable clamp.

Connect the black

lead

output

strip

lug

(8-3).

Connect

the

orange lead to lug

(8).

Connect

the

yellow

lead

lug

#5.

30("A'"Connect one

end

of a

red wire

output

strip

lug

(8-2).

Connect

the

other

end

of this wire to

eyelet

# 1

the

front

PC-10

(8).

(

Connect

the

black wire from

lug

the

right

-hum

control

lug

(no

symbol)

the

four-

section filter

capacitor

(8·3).

Place

this

wire

against

~he

rear

panel.

32(

Connect one of

the

green wires from

the

left

hum

control to lug

of terminal

strip

T8-2

(8-4).

Connect

the

other

green wire to lug

T8-2

(8-4).

Position these wires

under

the

cable clamp.

33 V

Connect

one of the green wires from

the

right

hum

control to lug

of terminal

strip

T8-2

(8-5).

Connect

the

other

green wire to lug

T8-2

(8·5).

Position

these

wires

under

the

cable clamp.

Now

tighten

the

hardware

holding

the

cable clamp.

34(.,t

Attach

the

rear

panel sub-assembly to

the

main

chassis with four sheet-metal screws, using two on

each

side in

the

holes provided.

(~Pass

the

line

cord

through

the

rubber

grommet

mounted

in the

rear

panel,

and

push

through far

enough to tie a

knot

from

the

end.

Tie

the

knot

Then,

separate

the

two conductors of

the

line cord

for 2".

Cut

'h" from one of them,

and

strip

and

tin

ends

of both.

(VConnect

the

shorter

the

two line

cord

conductors

lug

of AC

outlet

(8-2).

Connect

the

longer

conductor to lug

outlet

(8-2).

Now

tum

the

chassis over.

37(vj

Twist

together the two red wires from

input

sockets

and

#10

and

the

black wire from

the

short

lugs

between them. Connect

the

red

wire with

the

pre-

viously

bent

end

eyelet

#18

the

PC-ll

cir-

cuit

board

(8).

(Note

the

correct wire position

shown on

the

pictorial diagram.)

Twist

another

tum

the

black wire

around

the

remaining

red

wire

and

connect

the

black wire

eyelet

the

PC-ll

circuit

board

(8-2).

This

the

second wire con-

nected

this

eyelet. Connect

the

remaining

red

wire to lug A-8 of

the

selector switch

(8).

Position

these wires from

the

rear

panel

against

the

main

chassis.

38(~ist

together

the

two

gr~en-·Wires

from

input

sockets

and

the

black wire from the

short

lugs betweeft them. Connect

the

green wire

with

the preyiously

bent

end

eyelet

the

PC-ll

circuit

board

(8).

(Note

the

correct wire

position shown

the

pictorial

diagram.)

Twist

another

tum

the

black

wi,re

the

remaining

green wire

and

connect

the

black wire to

eyelet

# 1

the

PC-ll

circuit

board

(8-2).

This

the

second

wire connected to this eyelet. Connect

the

remain-

ing

green wire to lug B-8 of the selector switch

(8).

Position these wires from

the

rear

panel

against

the

main

chassis.

39 (

Connect

the

yellow wire from

input

socket #16 on

)he

rear

panel to lug A-I of

the

selector switch

(8-2).

40(

D(Connect the orange wire from

input

socket

#15

/Iug

A-12

(8).

41(""') Connect

the

red

wire from

input

socket

#14

to lug

A-ll

(8).

42~

Connect the brown wire from

input

socket

#13

lug A-lO

(8).

(v{

Connect

the

yeUow wire from

input

socket # 8 to

lug B-1

(8-2).

44(JConnect

the

orange wire from

input

socket

lug B-12

(8).

45(

VConnect

the

red

wire from

input

socket

to lug

B-ll

(8).

Connect

the

brown wire from

input

socket # 5 to

lug B-lO

(8).

This

completes

the

wiring of the..-ubit. DO

NOT

PLUG

THE

AC CORD

UNTIL

THE

TUBES

HAVE

BEEN

INSTALLED

AND

THE

COVER

AND

BO'ITOM

PLATE

ARE

SECURELY

PLACE.

SPECIAL

INSTRUCTIONS FOR OPTIONAL

120-240

VOLT POWER TRANSFORMERS

BLACK

Dynakit

8CA-35 amplifiers

supplied

with optional power

transformer PB-028

can

wired for

use

with

either

120

or 240 volt, 50

60 cycle,

power sources,

follows:

For r

Volt

Operation

1( ) Connect

the

black lead from

the

power transformer

to lug

of AC

outlet

2( )

Connect

the

black-and-white

lead

from

the

power

transformer to lug #1of AC

outlet

(8-3).

3( ) Connect

the

violet lead to lug Aon

the

fuse hoide

)Connect

the

violet-and-white lead to lug Aon

the

fuse holder

(8-2).

VIOLET

WHITE

BLACK

aWHITE

VIOLET

240·yolt

•

VIOLET

aWHITE

BLACK

aWHilE

VIOLET

120·Yol'

The

bottom

plate

and

the cover

are

attached

the

same

time, by

setting

the

amplifier chassis

the

bottom plate,

which fits outside

the

main

chassis,

and

then

lowering

the

cover

onto

the

chassis.

The

chassis, bottom

plate

and

cove

are

fastened together by four

sheet

metal screws throu

the

sides of

the

cover.

This

should be done before

the

fron

panel

is installed.

Install

the

pilot

light

jewel

in-

serting

from

the

front of

the

panel,

gripping

the

jewel

spring

with pliers

to squeeze

open,

and

sliding

the

spring over

the

jewel

hold

place.

The

panel

should

then

placed

over

the

control shafts,

and

nuts

placed

the

control

shaft

bushings

hold

the

panel

place.

Use

care

attaching

the

nuts

to avoid scratching

the finish of

the

panel.

The

cover

can

afterward

be removed,

if necessary,

without

removing

the

front panel.

All

the

knobs of

the

8CA-35 use small

set

screws to

secure

them

the

shafts. Asmall tip screwdriver is

required.

The

two large knobs go

the

selector switch

shaft

and

the

volume control shaft.

The

selector switch

shaft

has aflatted portion,

and

the

set

screw

the

knob

should be tightened

against

the

flat.

Then

when

the

knob

rotated

fully counter-clockwise,

the

index

mark

the

knob

should

point

"Tape

head".

The

balance control

and

volume control knobs should be

set

that

the

full counter-clockwise

point

corresponds to

7o'clock

aclock face,

and

then

full clockwise

rotation

will correspond to 5o'clock.

This

makes

the

index on

the

balance control

point

to 12 o'clock for nominally

balanced

operation. However,

either

of these knobs

can

installed

offset if desired so

that

the

12 o'clock position represents

average volume

and

balance

your

individual system.

The

bass control knob should be

set

that

full counter

clockwise is

6o'clock,

and

the

treble control knob

set

that

full clockwise is

6o'clock.

The

12 o'clock position

will

then

the

electrically "flat"

setting

for each.

Tum

the

chassis upside down,

and

shake

vigorously to

dislodge

any

wire clippings

bits of

sol~er.

The

tubes

and

the

fuse should now be mstalled.;

the

pIC-

torial

diagram

shows

the

location of each tube.

IMPOR-

TANT:

When

inserting

the tubes

their

sockets for

the

first time,

the

socket should be

supported

from below

the

chassis to avoid

strain

the

circuit

board

because of

the

tight

fit of

new

sockets.

V-I

and

V-2

are

12AX7;ECC-83

tubes

and

are

installed

PC-ll.

V-3

and

V-4

are

7199

tubes; one of each is

installed

on each

PC-10

the

socket

closest

the

PC-ll

board. V-5, V-6, V-7

and

V-8

are

6BQ5;EL-84/7189 tubes,

and

they

the

remaining

PC-10 sockets.

Insert

the

pilot

lamp

its

socket.

The

four

rubber

feet should be

installed

the

corner

holes of

the

bottom plate.

mount

each foot,

insert

machine screw

the

recessed

end

the

foot,

and

secure

with

nut

the

inside of

the

bottom

plate.

PLACES

TO DOUBLE-CHECK

AFTER

WIRING

sure

that

all

mounting

screws

and

nuts

are

tight.

Compare

the

wiring of each of

the

tube sockets

that

shown

the

pictorial diagram. All connections should be

securely soldered, with enough space between connections

the

tube

socket connecting lugs so

that

there is

chance

accidental short-circuit.

Compare

the

wiring to each lug of

the

filter capacitors

that

shown

the

pictorial

diagram. Check carefully to

see

that

all connections

have

been soldered,

and

that

excess

lead

length

has

not

caused

any

connection to short-circuit

the

chassis.

Examine

all

connections with

particular

care,

be sure

that

none

them

have solder blobs which

project

enough

to touch

the

bottom

plate

when

is installed. Check

the

terminal

strips

and

the

filter capacitors

particular.

Check

each

lug on

each

the

controls

the

front

panel, to be

sure

that

all of them

have

been soldered.

Check

the

twisted wires

the

ends

where

they

have been

soldered to see

that

the

insulation has

not

melted

to cause

shorted

condition.

This

will occur

too

much

heat

has

been

applied

when soldering these wires

and

they have been

twisted too tightly.

Pay

particular

attention

the

leads

going to

pins

and

of tube sockets V-5, V-6, V-7

and

V-B,

and

to lugs

#1,

#2,

and

of terminal

strip

T8-2.

The

wires to

the

selector switch

should

be positioned

shown below.

Note

particularly

the

twisted

pairs

lugs A3

and

A4,

and

to lugs B3

and

B4.

These

should

be close

the

front surface of

each

wafer.

for

240

Volt

Operation

1( ) Connect

the

violet-and-white

lead

to lug # 1 of ter-

minal

strip

TS-l.

)Connect

the

black-and-white

lead

to lug

of ter-

minal

strip

TS-1

(S-2).

3( ) Connect

the

black

lead

lug # 1 of

outlet

(S-2).

4( ) Connect

the

violet lead to lug Aon

the

fuse

.holder

(8).

When using

the

240 volt connection, aone

ampere

slo-

blo fuse should be

used

instead

the

two

ampere

fuse

recommended for

the

120 volt connection.

CASE

OF TROUBLE

Although

your

SCA-35 should function

properly

after

assembly, sometimes

error

of wiring

adefective com-

ponent

may

require trouble shooting.

The

location of a

difficulty

can

be determined most efficiently if asyste-

matic

approach

used.

This

is based

understanding

the

inter-relationship between

the

different sections of

the

circuit,

and

reference to

the

section which describes

the

circuit will be helpful in achieving

this

understanding.

The

suggestions for servicing which follow

are

based on

trying

to localize the circuit section which is

fault.

Naturally,

you

should

check

and

double check

your

wir-

ing

afirst

step

in trouble shooting.

is good

have

somebody else check

through for you,

may

see

error

which

you

overlook consistently.

This

checking

can

be done with

the

pictorial diagrams

with

the

step-by-

step instructions.

you

use both,

you

will have adouble

check

the

accuracy

of wiring. Look

not

only

to see if

all

ires

and

components

the

correct points,

but

also to

see

that

all

solder connections

are

good

and

that

wires

parts

touch spots where

they

should not. Sometimes a

bit

of solder will

run

from one

point

another

where no

connection is desired. Sometimes alead is left too long

and

hangs out, touching

another

point. All connections

should be examined

with

this

in mind.

Another

source of trouble is

that

wires

are

twisted so

tightly together

that

they

break

through

the

insulation

and

cause

short

circuits -

the

wire itself

may

be broken

within the insulation if twisted too tightly.

One general test should be

made

before serious trouble

shooting begins.

This

is to determine whether

the

fault

the

SCA-35

associated equipment. Sometimes, con-

nections to

the

loudspeakers

are

fault,

may

that

the

pickup cartridge is

not

connected properly in

the

player.

Pilot

Light

and/or

Tubes

Not

light

after

plugging

the

SCA-35

into

outlet

and

turning

the

power switch on,

the

pilot light does

not

on,

see whether

there

is a

normal

glow

the

center

the

tubes.

the

tubes glow while

the

pilot

light does

not

light,

then

the

fault

is in

the

pilot

light itself -

and

the

bulb

should be replaced -

the

wiring to

the

pilot

light

socket.

This

wiring should be traced to see whether

the

connections

are

correct

and

soldering makes good contact.

some of

the

tubes light,

but

others

do not,

then

the

heater

wiring to

the

unlighted

tubes

should be traced.

There

are

two sets of

heater

wires, a

set

for

each

channel, one of

~hich

is brown

and

brown-white,

the

other

green

and

green-

....

hite.

These

should be traced from

the

PA-774 transformer

to TS-2 to see

the

wiring compares with

the

pictorial

diagram.

all

the

tubes

one

channel

light,

but

none

the

other

channel,

interchange

the

brown with green wires

and

brown-white with green-white

temporarily

determine

whether one of these sets

windings is defective.

For

example,

the

interchange

should

make

tubes

light which

were formerly

not

lighted,

then

there

nothing

wrong

with

the

wiring to the tubes,

hut

most probably there is

something wrong with

the

wiring from

the

transformer

(which should be

returned

DYNA

Company

for replace-

ment

this

case).

This

principle of

substitution

is helpful

for locating

the

source of trouble.

neither

tubes

nor

pilot lamp light,

then

the

first

thing

to check is

the

fuse.

this is blown,

another

the

same

rating

should be used, 2

ampere

(except

ampere

for 240

volt

models).

the

second fuse blows,

then

is essential

determine

the

reason for this

instead

of continuing to

replace fuses.

Under

no circumstances should. afuse

higher rating be used.

Siown

fuses

The

fuse will blow

there

is a

short

circuit in

the

equip-

ment.

ohmmeter

is available, resistance measurements

should be

made

the two

and

four-section electrolytic

capacitor

terminals.

Unplug

the

power cord

and

discharge

each section of

the

capacitor

to ground before making

any

these

measurements.

The

resistance to ground should be

over 50,000 ohms

all sections except

the

blank

terminal

the

four-section

capacitor

where

should be

about

ohms. Any lesser resistance values indicate

either

capacitor

failure

path

to chassis which

should

not

exist. Discon-

nect

wires to each

capacitor

section to isolate

the

capacitor.

All sections should

read

high resistance once wires

are

disconnected -if not,

the

capacitor

fault.

one of

the

silicon diodes is defective,

has been

installed

backwards,

the

four-section

capacitor

will prob-

ably

have been

permanently

damaged.

similar

fashion,

the

four-section

capacitor

is defective,

may

cause the

failure of

the

silicon diodes. Therefore, if

either

capacitor

diodes

are

found to be

fault, both should be replaced.

Blown fuses

can

also indicate adefective PA-774 trans-

former

(though

this

rare

possibility).

check for

this, disconnect all leads of the PA-774 except the two

black

primary

leads;

and

with these leads

position where

they touch

neither

each

other

nor

other

components, plug

the

unit

and

turn

on.

the

fuse blows

under

this con-

dition, the trouble is definitely in

the

PA-774.

the·PA-774

is proven satisfactory

this test,

test

the

diodes

and

capacitors

disconnecting all wires to

the

capacitors

except

the

wire from lug

TS-l

to lug

the

four-section filter capacitortleaving

the

resistors on

the

capacitor

terminals.

plugging in

the

unit

and

turning

then

does

not

blow afuse, these components

are

exoner-

ated,

and

is necessary to seek a

short

circuit elsewhere

the

circuit.

The

output

tubes

can

be tested

the

source of blown

fuses by removing all

the

6BQ5's

simultaneously

from

their

sockets.

this cures fuse blowing,

then

one of

them

probably bad.

The

unit

should

never be

operated

with

only

one, two

three

these

four tubes

inserted

damage to

the

remaining tubes is probable.

Heater

glow

the

top

and

bottom of each tube is normal,

but

the

plate

(the

large

black metal

part)

the

output

tubes glows red

indicates

aprobable

short

the

tube

any

the

out-

put

tube

sockets,

short

the

chassis of some

part

the

heater

wiring.

Both

Channels

Not

Working

Should

neither

channel

function,

there

the

possibility

that

similar

mistake

has

been made in

the

wiring to both

sides.

This

unlikely situation,

but

should be checked

by visual comparison of

the

wiring with

the

diagrams.

Generally,

the

cause of

malfunction

both

channels

together lies

the

one section of

the

unit

which

com-

mon to both channels -

the

power supply.

The

checking of

this

section is covered earlier.

is also possible

that

the

unit

is working on

radio

other

high level

input,

but

not

on phono

tape

head.

this is

true

for

both

channels

together, then

the

power

supply

wiring which connects to

the

PC-ll

board should be

checked,

this is

the

only

element

common to both chan-

nels in

the

preamplifier section.

One

Channel

Not

Working

tubes

one

channel

not

light,

the

heater

circuits

must

be checked

described above.

Tubes

can

be inter-

changed between

the

two sides to see if

substitution

shows

faulty

tube.

this cures

the

bad

channel,

then

evi-

dently

the

faulty tube has been located.

not

tube

which causes

the

trouble,

then

necessary to determine whether

the

preamp

section

(the

PC-ll)

the

amplifier section

(the

PC-lO).

radio

input

satisfactory while

phono

is not,

then

the

trouble

the

PC-ll

section which

handles

phono

and

tapehead

inputs,

the

wiring associated with

the

selector switch.

inputs

function,

then

the

difficulty is

either

in the

front panel wiring which includes the tone control sections,

the

PC-lO

section

the

Z-565

output

trans-

former which connects to

that

channel.

The

wiring of the

front

panel

must

carefully

compared

on both left

and

right

channels.

is possible to re-do

the

wiring

and

to inter-

change

the

two PC-lO

boards

determine

whether

the

fault

one of these.

is also possible

interchange

the

Z-565

output

transformers

try

isolate

the

trouble.

However, afault

the

output

transformer is most unlikely,

and

this should be tried

last

resort.

both

channels work

radio

other

high level

input,

but

only

one works

phono or tapehead

input,

then

the

trouble is in

either

the

PC-ll

board

the

selector

switch

the

front

panel

wiring from selector switch

through

the

front panel controls.

The

PC-ll

board has

both

preamplifier sections

aparallel

arrangement,

so com-

parison visually of wiring

and

parts

should

indicate

whether

there

any

difference between these sections.

Each

section of

the

selector switch should be identical

appearance

and

in wiring.

These

should be compared care-

fully.

The

12AX7's on

the

PC-ll

should be interchanged to

see if one is

fault.

Hum

and

Noise

the

unit

is working,

but

there

is excessive

hum

noise,

the

first

step

is to see whether

the

trouble is in

the

SCA-35

associated equipment.

The

SCA-35 should be

checked alone, with all

other

equipment

except

the

speakers

disconnected,

and

with

the

cover

and

bottom

plate

the

SCA

secured in place.

the

hum is reduced

without

the

other

equipment,

then

will be necessary to determine

what

kind

of ground connections

are

necessary between

equipment

reduce

the

hum. Sometimes connecting wires

from chassis to chassis

are

good, sometimes

they

are

harm-

ful. Reversing line plugs on associated

equipment

may

helpful.

must

understood

that

hum

which disappears

when associated

equipment

is disconnected

turned

off,

not

aproblem of

the

SCA-35.

Hum

which persists

after

other

equipment

is eliminated

asource of trouble

generally a

result

either

faulty

wiring

afaulty tube. Wires which

are

not

positioned

shown

the

diagrams,

may

be a

cause

of hum.

This

particularly

true

for

the

wires which lead from

the

PA-7

transformer, since these wires

carry

currents

which

may

be asource of hum.

tube

causes

the

problem, then

not

likely to

appear

in both

channels

simultaneously.

the

hum

is loud

with

the

volume control

turned

.down,

then

is most likely

to be associated with

the

7199 tube.

occurs

phono

tapehead

inputs

with

the

volume

turned

abit,

then

most

likely to be associated with

the

12AX7 tube for

the

channel which shows

the

hum.

These

tubes

can

checked

substituting

the

other

channel.

objectionable level of hiss is

most

likely caused by a

defective resistor

printed

circuit

board.

heard

with

the

volume

turned

down,

is likely to be

part

of the

7199

circuit

can

often be located by wiggling

the

body

the

resistor (using insu]ated pliers) to see if

the

hiss is

affected.

is on

phono

tapehead

input,

with volume

turned

up,

then

the

same possibility

applies

the

12AX7

circuit.

Some

hum

and

hiss will always exist -

depending

speaker

efficiency

and

other

factors. However,

should be

negligible

normal listening levels.

very

high

levels,

some noise will always be audible,

but

of course this will be

masked

the

loud sound.

With

the

volume control

minimum, noise with a

shorted

input

should be less

than

millivolts across

the

16 ohm

output;

with volume

maxi-

mum,

should

not

exceed 40 millivolts

this point.

Sometimes,

the

magnetic field

around

the

PA-774 trans-

former

may

cause some vibration of

the

cover which is

audible

abuzzing sound.

This

can

be e]iminated by

placing a' small wedge of fibreboard

wood

top of

transformer, between

and

the

cover.

Distorflon

distortion is encountered,

the

first thing to do is to

make sure

that

all

inputs

and

outputs

are

properly con-

nected

and

properly

functioning.

the

leads to aloud-

speaker

have

frayed cables

and

touch

several screws simul-

taneously,

this

can

be asource of distortion.

aceramic

cartridge is

inserted

into

the

magnetic

cartridge

input

(or

if a

tape

amp

goes

the

tapehead

input)

there will be

overloading of

the

input

and

severe distortion.

the

trouble seems to be

the

SCA-35,

then

determine

one channel

both.

in both channels,

the

only

circuitry

common to

both

channels is

that

the

power

supply

and

the

ohm

resistor in

the

cathode circuits of

the

6BQ5 tubes.

only

one

channel

has

distortion, tests similar to those

described previously should be used to localize

the

prob-

lem

and

tubes should be

interchanged

see if they

are

cause of it.

Inspection

parts

the

printed

circuit boards

should

made

to see if both sides of

the

circuit

are

identical.

Voltage

Measurements

The

voltage

chart

shown with

the

schematic diagram will

be of considerable

aid

in troubleshooting if

there

vacuum

tube

voltmeter

similar

test

instrument

available.

Voltages

through

the

circuit

should

be compared carefully

with this chart. Deviations

to 20%

are

not

signs 0

abnormality,

but

past

this

range

they

indicate amalfunc

tioning of

the

circuit

that

point.

Such

measurements

can

help

locate defective

parts,

miswiring,

bad

tubes.

volume

balance

bass

treble c

hum

V 1 1

V 2 1

V 3 •

V 4

V 5

V 6

V 7

V 8

D 2

All

resistors are

watt, 10% unless otherwise noted.

R35 470.000 ohms C 9 330

mica

R36 470,000 ohms C10 3.3

10%

82,000 ohms 5% C

10 nf 10%

R38 22.000

ohms

C12 10

10%

R39 2200 ohms 1watt C13 3.3

10%

R40 2200 ohms 1watt C14 3.3

10%

ohms

5watts C

22 nf 10%

ohms

5watts

C16 22 nf 10%

C17

.lmfdI16V.

.1.

mfd @16

C18 1mfd

250v.

C222 nf @400v. C19

mfd 400

mfd

@4oov.

C20 1mfd 400 v

C4330 pf mica 5% C

pf @600

c53.3 nf 10% C22 .02 mfd @500

C 6

mfd @16

C23

50/50

mfcl

450

C 7

22nf@400v.

C2460/40/[email protected]

mfd @400

100 @25

1.2

megohms

47,000 ohms

390 ohms

18,000 ohms 5%

100,000

ohms

4~000

ohms

1.:>

megohms

10,000 ohms

18,000 ohms

4.7

megohms

270.000 ohms 1watt

560 ohms 5%

22,000

ohms

1watt

120,000

ohms

27,000 ohms 1watt 5%

R19

R20

R21

R22

R24

R25

R26

R27

R29

R30

R32

R33

R34

1.2 megohms

150,000 ohms 1watt 5%

5,600 ohms 5%

120

ohms

1watt 5%

120

ohms

1watt 5%

1.2

megohms

47,000

ohms

390 ohms

18,000 ohms 5%

100,000 ohms 5%

47,000 ohms

1.5

megohms

1.2

megohms

150,000 ohms 1watt

5,600 ohms 5%

120

ohms

1watt 5%

120 ohms 1watt 5%

R 1

R 2

R 3

R 7

R 8

R 9

R10

R12

R13

R14

R15

R16

R17

VOLTAGE

CHART

tlNtlSED PINS

MAY

HAVE

INTERNAL

CONNEI

SOME

TtlBES

(DEPENDING

BRAND),

MAYI

PEAR

THESE

POINTS.

VOLTAGES

MEASURE

WITH

Tv.

PIN I2345

via

180

-.2

(12AX7) I

V3aV4

r----l

(7199) 255

6.3

V-5-6-7-8

r----l

(68Q5)

6.3

TS-I

LUG

380

315 315

...

•

.to

C24

LUG

380

370

350

...

•

C23

LUG

320

250

ST~"EOI

"0"0

Ri5

CII

CI3

'r/

(

CI2

:II '

'•

0•

•

112

R271

III

'"r'

110

1,,

•

LEVEL(ot'---+;

SPAREl~----o

TAPE

RECORD(Ot~-----r1""'-""-""'--:

RAOIO(~---o

PHONO

FROM

TAPE

AMP(~-----()

RAOIOCo}------<>

LEVELlQ1'---+,

FROM

TAPE

HO(Q'~-""""-o

FROM

TAPE

AMPfoT------<>AII

SPARE~

---()

LEVELl

C»--'-.IJ'--o

TAPE

RECORO(~----~!-o'-"';";_

LEVEL(~--+J~

FROM

TAPE

HOll»---.I-<lU

SCHEMATIC

DIAGRAM

Silicon rectifier, 500

ma,

1000 PIV

2Silicon rectifier, 500

ma,

1000 PIV

'olume control-250,OOO ohms

lalance control-750,OOO ohms

lass

control-2

megohms

reble control-500,OOO ohms

lum control-l,OOO ohms

, 1 12AX7/

ECC-83

, 2 12AX7/ECC-83

, 3 7199

, 4 7199

, 5 6BQ5/EL-84

, 6 68Q5/EL-84

, 7 68Q5/

El-84

, 8

6BQ5/El-84

IART

56789

i.3

10~

0.25

--,

360

0·

;,3

365

315

CONNECTIONS,

THEREFORE

lOJ,

AlAYHAVE

VOLTAGES

AP-

V,M.

EYELET

PC-II

C23

~24

~_-.-'V..::.:[L~

16il

)o-_+,O=.::A~

8il

'----;f-8,LK

~----'T"""'"

111:

...

C22

en 4

...

BLJ:

J20

...

PA-774

:::)

...

....

".-_-t-'v",n'-f2}

16il

>--_+-,O!.!!.A~

...

Table of contents

Popular Amplifier manuals by other brands

STAX

STAX SRM-252S user manual

Hafler

Hafler SE120 Service manual

Octasound

Octasound RAAX2 owner's manual

Audio Technica

Audio Technica AT-PHA55BT user manual

Iron sounds amplification

Iron sounds amplification JA-TMB PCB Installation/assembly guide

Phonic

Phonic CA35 user manual

Decware

Decware SE84UFO owner's manual

Polytron

Polytron HV 36122 N operating manual

Montalvo

Montalvo M Series Technical manual

Rotel

Rotel RTC-965 owner's manual

Redx

Redx sapphire iii owner's manual

AOI

AOI Quantum12 Installation and operation guide

Shinybow USA

Shinybow USA SB-3702 instruction manual

Sherwood

Sherwood am-9080 Service manual

FONESTAR

FONESTAR MA-680RGUZ instruction manual

Nobels

Nobels Streetman 10 owner's manual

Budda

Budda Stringmaster instruction sheet

Alesis

Alesis POWER AMPLIFIER RA150 Reference manual

Dyna Dynakit SCA-35 Installation instructions

Popular Amplifier manuals by other brands