•
•
•
TABLE
OF
CONT
EN
TS
Connecting the 4270
2
Source Devices
4
Remote Speakers
4
Speaker Phasing
5
Speaker Placement
5
Front
Panel Features
7
Mode Switch
7
Dimension
8
SQ Decoder
8
Balance Controls
8
Selector Switch
8
Bass,
Mid
and Treble Controls
8
Monitor
Switch
for
Tape 1!Tape 2
8
Monitor
Switch
for
Tape/Source
8
Main and Remote Spkr Switches
9
Power Switch
9
Front
and Rear Phones Jacks
9
Loudness
9
Hi
Filter
Switch
9
Tuning Meter
9
Tuning
9
FM Muting Switch
10
Volume
10
Dolby
Switch
10
Record Level
(L)
(R)
10
Play Cal.
(L)
(R)
10
400Hz Tone Switch
10
Rear
Panel
Features
11
Phono Jacks
11
CD-4/
AUX
Jacks
11
Tape
Monitor
In and Tape
Monitor
Out
Jacks
11
FM Antenna Terminals
11
AM Antenna Terminal
11
FM Quadradial
Output
Jack 12
FM De-Emphasis Switch
12
Dolby
FM Preset Level Controls 12
Muting Level Control 12
Power Mode Switch 12
Pre Out, Main In Jacks 12
Connecting an External
Amplifier
for
Rear Channels 12
Connecting an External
Amplifier
for
Front
Channels
12
Chassis
Ground Binding Post
12
Main and Remote Speakers
12
Connection
to
AC
Outlet
13
AC Convenience Outlets
13
Remote Control
13
External Decoder Connection
13
Tape Recording
13
Basic
Dolby
Process
14
Dolby
Calibration
14
Procedure
for
Playback Calibration
14
Procedure
for
Record Calibration
15
Use
of
the
Dolby
System on FM
Broadcasts
16
FM De-Emphasis Switch
16
Dolby
Mode Chart
16
Technical Description
18
General
18
Functional Description
18
Frond End
18
IF
Stages
18
Limiter
18
FM Stereo Demodulator
18
Muting
Circuit
18
AM Tuner
18
Phono
Amplifiers
19
Selector Switch
19
Monitor
(Tape/Source) Switch
19
Monitor
(Tape 1 or 2) Switch
19
Tone Control
19
Power
Amplifier
19
General Requirements
19
Installation
of
Walnut Cabinet
20
Service Notes
20
LIST F
ILL
USTRA
TI
ONS
1. Rear Panel Connection
Facilities and Adjustments 2
2. Loudspeaker System Connections 3
3. Connection Diagram 4
4. Speaker Placement 6
5. Mono Mode Sound Dispersion 7
6. 2-channel Mode Sound Dispersion 7
7. Discrete Mode Sound Dispersion 7
8. Vari-Matrix Mode Sound Dispersion 7
9.
Front
Panel
Controls and Jacks 8
10. Stereophone Plug 9
11.
FM/AM
Antenna Connections 11
12. AM Ferrite-rod Antenna 11
13. Quick-Connect Speaker Terminal 13
14. Block Diagram 17
15. Packing Instructions 20
TABLE
1.
Dolby
Mode Chart 16