Marantz 2215 User manual

SERVICE

MANUAL

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TABLE

OF

CONTENTS

SECTION

PAGE

INtrOCUCTION

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and

Pre-amplifier

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Main

Amplifier

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Test

Equipment

Required

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Servicing

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AM

Alignment

Procedure

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FM

Alignment

Procedure

........-.

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Stereo

Separation

Alignment

...........

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Muting

Threshold

Adjustment

......

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Audio

Adjustment

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24

LIST

OF

ILLUSTRATIONS

FIGURE

NO

PAGE

1.

Remove

the

Terminal

Cover

...........00.eeeeeues

Polis

ateishins

Weta

aia,

ie

aehalee

4

2.

Voltage

Conversion

Chart

......

0.

cece

ete

tence

nee

eee

ee

eee

erene

5

3.

Dial

Stringing...

......

0.0

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cece

ee

eee

ees

ee

Ne

eee

eT

8

4.

Front

Panel

Adjustment

and

Component

Locations

...............0

eevee

9

5.

Main

Chassis

Component

Locations

(Top

View)

............0eeeee

cece

eeeee

9

6.

Rear

Panel

Adjustment

and

Component

Locations

...........0.020

0

cece

eens

10

7.

Main

Chassis

Component

Locations

(Bottom

View)

..............0+65

sai

bratguieiet

10

8.

FM

Front

End

and

AM

Tuner

Assembly

P100

Component

Locations

.........-:

11

9.

FM

IF

Amplifier

and

Detector

Unit

Assembly

P200

Component

Locations

.....-.

11

10.

Muting

Control

and

Meter

Amplifier

Unit

Assembly

P300

Component

Locations...

12

11.

MPX

Stereo

Decoding

Amplifier

P400

Component

Locations

............+++6:

12

12.

Phono

Amplifier

Assembly

P900

Component

Locations

............2

0008

e

eee

13

13.

Tone

Amplifier

Assembly

P500

Component

Locations

.............0

ce ee

eee

13

14.

Tone

Control

Volume

Unit

Assembly

P650

Component

Locations...........--:

14

15.

Power

Amplifier

Assembly

P700

Component

Locations

............0

eee

eres

14

16.

Power

Supply

Assembly

P800

Component

Locations

..............0

ee

eeee

15

17.

Loudness,

Muting,

High

and

Low

Filter

Switch

Unit

Assembly

P600

Component

Locations

..........

00.

c

ee

cece

ete

eee

nnn

15

18.

Schematic

Disdram

4.044

5.4%

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tans

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ores

Re

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ews

16

INTRODUCTION

This

service

manual

was

prepared

for

use

by

Authorized

Warranty

Stations

and

contains

service

information

for

Marantz

Model

2215

Stereophonic

Receiver.

Servicing

information

and

voltage

data

included

in

this

manual

are

intended

for

use

by

the

knowledgeable

and

experienced

technician

only.

All

instruction

should

be

read

carefully.

No

attempt

should

be

made

to

proceed

without

a

good

understanding

of

the

operation

in

the

receiver.

The

parts

list

furnish

information

by

which

replacement

part

may

be

ordered

from

the

Marantz

Company.

A

simple

description

is

included

for

parts

which

can

be

usually

be

obtained

through

local

suppliers.

1.

Service

Notes

As

can

be

seen

form

the

circuit

diagram

the

chassis

of

Model

2215

consists

of

the

following

units.

Each

unit

mounted

on

a

printed

circuit

board

is

described

within

the

square

enclosed

by

a

bold

dotted

line

on

the

circuit

diagram.

1.

FM

Front

End

&

AM

Tuner

..

0...

ee

eee

mounted

on

P.C,

Board,

P100

2.

FMIF

Amplifier

and

Detector

Unit

........-....5555-

mounted

on

P.C.

Board,

P200

3.

Muting

Control

and

Meter

Amplifier

Unit

.............

mounted

on

P.C.

Board,

P300

4.

MPX

Stereo

Decoding

Amplifier

..........2...00000-

mounted

on

P.C.

Board,

P400

5.

Phono

Amplifier...

2...

ee

eee

mounted

on

P.C.

Board,

P900

6.

Tone

Amplifier

cso

cae

ao

Fs

eT

O

Ee

eS

mounted

on

P.C.

Board,

P500

7.

Tone

Control

Volume

Unit...

0...

2.0002

eee

ee

eee

mounted

on

P.C.

Board,

P650

8.

Power

Amplifier...

2.0...

ce

ee

es

mounted

on

P.C.

Board,

P700

©:

Power

Supp

de!

Grseanin

gw

aan

aie

eiere

i

ee

ware

ka

ea

mounted

on

P.C.

Board,

P800

10.

Loudness,

Muting,

High

and

low

Filter

Switch

Unit

.......

mounted

on

P.C.

Board,

P600

2.

AM

Tuner

All

components

except

Tuning

capacitor

and

ferrite

bar

antenna

are

mounted

on

a

printed

circuit

board

P

100.

The

AM

signals

induced

in

a

ferrite

bar

antenna

are

applided

to

the

base

of

Mixer

transistor

H102

through

a

capacitor

of

C109,

while

the

local

oscillator

voltage

is

injected

to

the

emitter

of

H102

through

the

capacitor

C157.

Both

AM

signals

and

oscillating

voltage

are

mixed

at

the

base-emitter

junction

and

converted

into

455

KHz

intermediate

frequency.

The

resulting

IF

signal

is

applied

to

the

first

IF

transformer

F101

consisting

of

one

ceramic

filter

and

two

tuned

circuits.

The

output

of

F101

is

led

to

the

transistor

H103

which

in

turn

apply

its

output

to

the

transistor

of

H104.

The

fully

amplified

IF

output

is

then

applied

to

the

diode

H107

to

detect

audible

signal

through

the

detector

transformer

L102.

The

detected

audio

signal

is

filtered

and

amplified

and

the

final

audio

output

is

obtained

from

the

collector

of

H105

and

applied:

one

to

the

tape out

jacks

through

monitor

switch

on

the

front

panel

and

the

other

to

the

function

rotary

switch.

The

DC

component

of

the

detected

IF

signal

is

used

as

a

AGC

voltage

to

control

emitter

current

of

H103

and

H102

through

the

resistor

R112

and

R106

respectively.

A

part

of

IF

signal

output

is

also

applied

to

the

diode

H108

through

a

capacitor

C123

and

rectified

to

obtain

DC

current

for

energizing

the

AM

signal

strength

meter

MOO1.

3.

FM

Tuner

The

FM

Tuner

section

of

Model

2215

is

divided

into

three

functional

blocks:

FM

front

end,

IF

amplifier

&

Detector,

Muting

control]

and

MPX

stereo

decoding

circuit.

FM

signals

induced

on

a

FM

antenna

are

led

to

FM

antenna

coil

L103.

These

signals

are

then

applied

to

the

FET

RF

amplifier

which

in

turn

applies

its

output

to

the

Mixer

H111

through

a

high-Q

tuned

circuit.

‘The

Mixer

convert

its

input

signal

into

10.7MHz

intermediate

frequency

and

amplifies

it.

The

H110

is

a

local

oscillator

and

its

output

is

injected

into.

the

base

of

Mixer

transistor,

the

injection

voltage

is

about

100

to

200mV.

The

10.7MHz

front

end

IF

output

is

led

to

the

amplifier

unit

through

a

coaxial

cable.

The

IF

amplifier

unit

consists

of

five

stages

of

IF

amplifiers.

Two

pieces

of

ceramic

filters

are

used

to

obtain

high

selectivity

a

pair

of

symmetrical

diode

limiter

is

also

employed

for

the

best

limitting

characteristics,

improved

capture

ratio

and

good

AM

suppression.

A

part

of

IF

amplifier

H202

is

rectified

by

the

diodes

H206

and

H207

and

its

DC

output

is

fed

back

to

the

gate

of

FET

RF

amplifier

to

decrease

the

gain

of

it

with

increased

input

signal

strength.

3-1

Muting

and

Auto-Stereo

Switching

Circuits

The

muting

circuit

consisting

of

all

solid-state

electrical

switching

has

been

incorporated

in

the

Model

2215.

The

DC

voltage

obtained

by

rectifing

a

part

of

IF

output

signal

from

the

H204

is

applied

to

the

base

of

H304

and

turns

on

it,

if

the

IF

output

is

greater

than

predetermined

level

(muting

threshold

level).

When

the

H304

is

turned

on,

the

H305

is

turned

off,

thus

allowing

the

_

emitter-collector

resistance

of

the

H305

increasing

and

the

collector

voltage

rises

about

8V.

The

increased

collector

voltage

increases

the

base

bias

voltage

and

makes

the

switching

transistor

H306

turn

on,

thus

decreasing

the

collector-emitter

resistance

to

near

zero

ohm

and

allowing

the

power

supply

path

to

the

IC

closed.

When

the

input

signal

is

lower

than

the

predetermined

level,

the

DC

output

obtained

is

small

and

can

not

turn

on

the

H304,

thus

the

H304

keeps

its

turn-off

state

and

this

makes

H305

turn

on,

decreasing

the

collector

voltage

and

turning

off

H306.

Thus

no

power

is

supplied

to

the

IC

H205

and

signals

below

the

threshold

level

are

muted

out.

The

muting

threshold

level

can

be

varied

by

adjusting

the

trimming

resistor

R306.

The

DC

voltage

developed

at

the

collector

of

H305

is

also

used

to

make

the

Auto-Stereo

switching

transistor

H403

turn

on

and

off.

3-2

MPX

Stereo

Decoding

Circuit

Non-equalized

audio

signals

are

applied

to

the

first

amplifier

H401

which

servs

as

a

tuned

amplifier

for

the

pilot

signal

in

the

composite

signals

and

as

a

buffer

amplifier

for

the

rest

audio

signals.

The

amplified

19KHz

pilot

signal

is

led

to

the

second

19KHz

amplifier

H402

and

further

amplified

if

switching

transistor

H403

is

turned

on

by

the

controlling

DC

signal

as

descibed

above.

The

19KHz

pilot

signal

is

rectified

by

the

doubler

circuit

consisting

of

H412

and

H413

to

obtain

synchronized

38KHz

signal

to

drive

the

H404.

The

H404

is

the

38KHz

tuned

amplifier

and

supplies

its

output

to

the

switching

matrix

circuit

consisting

of

four

diodes.

The

composite

signals

are

applied

to

the

center

tap

of

switching

transformer

L402-2

and

decoded

into

left

and

right

channel

signals,

then

both

channel

signals

are

led

to

the

crosstalk

cancelling

amplifier

wh

ich

utilizes

complementary

confuguration

with

NPN

and

PNP

transistors

through

de-emphasiss

net

works.

Transistors

H313

and

H314

are

buffer

amplifiers

and

their

outputs

are

led

to

the

function

switch.

3.3

Suggestion

for

Trouble

Shooting

of

FM

Tuner

3.3.1

Symptom:

No

FM

Reception

First

turn

ON

the

power

switch

and

try

to

tune

FM

stations.

Rotate

the

fly-wheel

tuning

knob

slowly

and

observe

the

FM

tuning

meter.

If

the

meter

deflect

at

several

frequencies

received,

the

circuits

preceding

the

IF

amplifier

H204

may

have

no

failure.

When

no

reading

is

obtained

in

the

meter,

check

FM

local

oscillator

circuit,

using

a

RF

VTVM.

The

normal

local

oscillator

voltage

is

one

or

two

volts

(rms)

at

the

tuning

capacitor,

depending

on

the

tuning

capacitor

position.

If

the

local

oscillator

voltage

is

normal,

all

voltage

distributions

in

the

FM

circuits

and

compare

them

with

those

shown

in

the

circuit

diagram.

When

the

tuning

meter

deflects

but

no

sound

is

obtained,

check

audio

circuits,

using

a

high

sensitive

oscilloscope.

3.3.2

Symptom:

No

Stereo

Separation

First

check

the

“MONO”

switch

is

in

normal

out

position.

Connect

a

FM

RF

signal

generator

output

modulated

by

a

stereo

modulator

to

the

rear

FM

antenna

terminals,

and

check

the

stereo

beacon

is

turned

on

or

not.

If

not

turned

on,

check

for

19

KHz

pilot

signal

and

38

KHz

switching

signal,

using

an

oscilloscope.

4.

Phono

and

Pre-amplifier

Signals

from

the

tuner

and

AUX

jacks

are

applied

to

the

selector

switch.

Signals

from

the

PHONO

jacks

are

applied

to

the

phono-amplifier

consisting

of

transistor

r'901,

H903

and

H905.

The

gain

of

the

amplifier

is

40

dB.

The

amplified

and

equalized

phono-signals

are,

then,

fed

to

other

section

of

the

selector

switch

which,

in

turn,

applies

output

signals

from

the

tuner,

phono-amplifier

and

AUX

jacks

to

the

TAPE

MONITOR

switch

and

TAPE

OUT

jacks.

The

TAPE

MONITOR

switch

applies

the

signals

to

the

balance

and

volume

controls.

The

controlled

signals

are

fed

to

the

pre-amplifier

consisting

of

H501,

H503

and

H505.

Frequency

response

of

the

amplifier

can

be

varied

by

BASS

and

TREBLE

controls.

The

controlled

output

are

then

led

to

the

main

amplifier

through

high

and

low

pass

filter

push-switches.

5.

Main

Amplifier

Transistor

H701

is

a

pre-driver

coupled

to

the

transistor

H703

through

capacitor

C711.

Transistor

H703

drives

the

inverter

transistors

H709

and

H710

which,

in

turn,

drive

the

power

stage

consisting

of

HOO1

and

HOO2.

Transistors

H705

and

H709

are

current

limitters

and

operate

as

power

protecting

circuits.

Excessive

currents

flowing

into

the

power

stage

are

detected

by

the

resistors

R741

and

R745

and

the

resultant

variations

are

applied

to

the

transistors

H705

and

H707

and

make

them

turned

on.

This

decreases

the

current

flowing

into

the

H709

and

H710.

In

this

way

the

currents

flowing

in

the

power

stage

(HOO1

and

HO02)

are

restricted

within

a

safe

value.

nEeRen

Beam

unl

-z.

6.

Audio

Trouble

Analysis

1.

Excessive

line

consumption

a.

Check

for

shorted

rectifiers

HOO7, H804,

H805.

b.

Check

for

shorted

transistors

HOO1,

HOO2.

Check

L002

for

short.

2.

No

line

consumption

or

zero

bias.

a.

Check

line

cord,

fuse,

shorted

HOO5,

HOO6,

H713

&

H7

14.

b.

Check

for

open

rectifiers

HOO7,

H804,

H805

or

open

Lo02.

3.

High

hum

and

noise

level.

a.

Check

filter

capacitors

C006,

C703,

&

C704.

4.

Parastic

oscillation

a.

Check

for

defective

capacitors,

C705,

C706,

C713,

C714,

C723

&

C724.

5.

Improper

clipping

a.

Check

for

proper

adjustment

of

R729

&

R730.

7.

Voltage

Conversion

This

model

is

equipped

with

a

universal

power

transformer

to

permit

operation

at

100,

120,

200,

220

and

240V

AC

50

to

60Hz.

To

convert

the

Model

2215

to

the

required

voltage

perform

the

following

steps:

(1)

Remove

the

top

cover.

(2)

Remove

the

Transformer

Wire

Connection

Terminal

Cover,

loosen

two

Cover

mounting

screws

on

the

rear

panel,

see

Fig.

1.

(3)

Change

the

jumper

wires

as

illustrated

in

Fig.

2

for

the

required

AC

voltage

and

replace

the

fuse

as

instructed.

CAUTION:

DISCONNECT

POWER

SUPPLY

CORD

FROM

AC

OUTLET

BEFORE

CON-

VERTING

VOLTAGE.

REMOVE

SCREW

REMOVE

THIS

COVER

Figure

1.

Remove

the

Terminal

Cover

For

|OO

V

Operation

For

200V

Operation

(Use2.5A

Fuse

)

(Use

|.S5AFuse

)

BROWN

GREEN

WHITE

RED

BLUE

YELLOW

BROWN

GREEN

WHITE

RED

BLUE

YELLOW

For

120

V

Operation

For

220V

Operation

(Use

2A

Fuse

)

(Use

1A

Fuse

)

BROWN

GREEN

WHITE

RED

BLUE

YELLOW

BROWN

GREEN

WHITE

RED

6LUE

YELLOW

For

240V

Operation

(Use

|A

Fuse

)

BROWN

GREEN

WHITE

RED

BLUE

YELLOW

Figure

2.

Voltage

Conversion

Chart

Peper

ne

be:

Bs

tw

4

9.

Test

Equipment

Required

for

Servicing

Table

1

lists

the

test

equipment

required

for

servicing

the

Model

2215

Receiver.

Manufacturer

and

Model

No.

AM

Signal

Generator

Test

Loop

FM

Signat

Generator

Stereo

Modulator

Audio

Oscillator

Oscilloscope

VTVM

Circuit

Tester

AC

Wattmeter

AC

Ammeter

Line

Voltmeter

Variable

Autotransformer

(0-140VAC,

10

amps.)

Shorting

Plug

Output

Load

(8

ohms,

0.5%,

100W)

Output

Load

(4

ohms,

0.5%,

100W)

Less

than

0.3%

distortion

Less

than

0.3%

distortion

Weston

Model

CVO-100P,

less

than

0.02%

residual

distortion

is

required.

High

sensitivity

with

DC

hori-

zontal

and

vertical

amplifiers.

With

AC,

DC,

RF

range

Simpson,

Mode!

390

Commercial

Grade

(1-10A)

Commercial

Grade

(0-150VAC)

Powerstat,

Model

116B

Use

phono

plug

with

600

ohm

across

center

and

shell.

Commercial

Grade

Commercial

Grade

Signal

source

for

AM

align-

ment

Used

with

AM

Signal

generator

Signal

source

for

FM

align-

ment

Stereo

separation

alignment

and

trouble

shooting

Sinewave

and

squarewave

sig-

nal

source.

Waveform

analysis

and

Trou-

ble

Shooting,

and

ASO

align-

ment.

Voltage

measurements.

Trouble

Shooting

Monitors

primary

power

to

Amplifier.

Monitors

amplifier

output

un-

der

short

circuit

condition.

Monitors

potential

of

primary

power

to

amplifier

Adjusts

level

of

primary

power

to

amplifier.

Shorts

amplifier

input

to

elimi-

nate

noise

pickup.

Provides

8-ohm

load

for

am-

plifier

output

termination.

Provides

4-ohm

load

for

am-

plifier

output

termination.

9.

AM

Alignment

Procedure

AM

IF

Alignment

1.

2.

Connect

a

sweep

generator

to

the

J102

and

an

alignment

scope

to

the

capacitor

C125,

Rotate

each

core

of

IF

transformer

F101

and

L102

for

the

maximum

height

and

flat

top

symmetrical

response.

AM

Frequency

Range

and

Tracking

Alignment

1.

2.

6.

Set

AM

signal

generator

to

525

KHz.

Turn

the

tuning

capacitor

fully

closed

(place

the

tuning

pointer

at

the

low

end.)

and

adjust

the

oscillator

coil

L101

for

maximum

audio

output.

Set

the

signal

generator

to

1650

KHz.

Place

the

tuning

pointer

in

the

high

frequency

end and

adjust

the

trimming

capacitor

C155-2

for

maximum

audio

output.

.

Repeat

step

1

and

2

until

no

further

adjustment

is

necessary.

.

Set

the

generator

to

600

KHz

and

tune

the

receiver.to

the

same

frequency

and

adjust

a

slug

core

of

AM

ferrite

rod

antenna

for

maximum

output.

.Set

the

generator

to

1400

KHz

and

tune

the

receiver

to

the

same

frequency

and

adjust

the

trimming

capacitor

C155-1

for

maximum

output.

Repeat

the

procedure

4

and

5

until

no

further

adjustment

is

necessary.

Note:

During

tracking

alignment

reduce

the

signal

generator

output

as

necessary

to

avoid

AGC

action.

10.

FM

Alignment

Procedure

1.

2.

Connect

a

FM

signal

generator

to

the

FM

antenna

terminals

and

a

oscilloscope

and

an

audio

distortion

analyzer

to

the

tape

output

jack

on

the

rear

panel.

Set

the

FM

SG

to

87.5

MHz

and

provide

about

3

to

5uV.

Place

the

tuning

pointer

at

the

low

frequency

end

by

rotating

the

tuning

knob

and

adjust

the

core

of

oscillator

coil

L106

to

obtain

maximum

audio

output.

.

Set

the

FM

SG

to

108.5

MHz

and

provide

about

3

to

5uV.

Rotate

the

tuning

knob

and

place

the’

tuning

pointer

at

the

high

frequency

end

and

adjust

the

trimming

capacitor

C152

for

maximum

output.

.

Repeat

the

step

2

and

3

until

no

further

adjustment

is

necessary.

.Set

the

FM

SG

to

90

MHz

and

tune

the

receiver

to

the

same

frequency.

Decrease

signal

generator

output

until

the

audio

output

level

decreases

with

the

decreasing

generator

output.

Adjust

the

RF

coil

L104

and

antenna

coil

L103

and

IF

transformer

L105

for

minimum

audio.

distortion.

.

Set

the

FM

SG

to

106

MHz

and

tune

the

receiver

to

the

same

frequency.

Decrease

the

signal

generator

output

until

the

audio

output

level

decreases

with

the

decreasing

generator

output.

Adjust

the

trimming

capacitor

C155-3

and

C155-4

for

minimum

distortion.

.

Repeat

the

step

5

and

6

until

no

further

adjustment

is

necessary.

.

Connect

a

DC

VTVM

with

1

V

range

selected

across

the

capacitor

C277

and

adjust

the

secondary

core

(black)

of

discriminator

transformer

L201

so

that

no

voltage

reading

is

obtained

on

the

VTVM

at

no

signal.

the

FM

SG

to

98

MHz

and

increase

the

output

level

1

KuV,

then

tune

the

receiver

to

the

same

frequency

so

that

no

deflection

is

obtained

on

the

VTVM.

Adjust

primary

core

(pink)

of

L201

for

minimum

distortion.

metas

Bean

ne

i

-z.

11.

Stereo

Separation

Alignment

1.

4.

Set

the

FM

SG

to

provide

1

KuV

at

98

MHz.

Tune

the

receiver

to

the

same

frequency

so

that

the

VTVM

connected

to

the

C227

will

give

no

readings.

.

Modulate

the

FM

SG

with

67

KHz

audio

frequency.

Connect

a

oscilloscope

to

the

R413.

Adjust

the

core

of

L403

for

minimum

height

of

the

67

KHz

signal

on

the

scope.

.

Modulate

the

FM

SG

output

with

stereo

composite

signal

consisting

of

subchannel

signal

only

(of

course

a

pilot

signal

must

be

included.).

Adjust

the

core

of

L410

for

maximum

audio

output,

then

modulate

the

signal

generator

output

with

a

stereo

composite

signal

consisting

of

L

channel

signal

only

and

again

adjust

the

core

of

L401

for

maximum

audio

output.

Adjust

the

trimming

resistor

R428

for

maximum

and

same

separation

in

both

channels.

12.

Muting

Threshold

Adjustment

1.

Set

the

FM

SG

output

to

provide

12.5uV

(IHF)

at

98

MHz

and

tune

receiver

to

the

same

frequency.

Adjust

the

trimming

resistor

R306

for

the

threshold

level

of

12.5uV.

(During

this

adjustment

turn

the

MUTING

push-switch

“‘on”’.)

13.

Audio

Adjustment

1.

Connect

a

VTVM

across

the

resistor

R747

and

adjust

the

trimming

resistor

R729

until

the

VTVM

reads

7.5mV

DC.

For

the

other

channel

connect

the

VTVM

across

the

R748

and

adjust

the

R730

for

the

same

reading.

.

Connect

a

oscilloscope

across

the

speaker

terminals.

Apply

an

audio

signal

of

1

KHz

to

the

AUX

jacks

and

increase

the

audio

signal

until

the

audio

output

on

the

scope

begin

to

start

clipping.

Adjust

the

trimming

resistor

R723

for

equal

and

symmetrical

clipping.

For

the

other

channel

adjust

the

R724.

POINTER

Figure

3.

Dial

Stringsng

Marantz 2215 User manual

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