Kenwood A-71 User Manual

STEREO INTEGRATED AMPLIFIER
a7
KENWOOD
SERVICE MANUAL
C 1987-9 PRINTED IN JAPAN
B51-3342-00(T)1, 272
Remote controller ass’y
(A70-0184-05}
Dressing piate (Remote control)
Knob (Balance)
(BO3-2323-04)
(K29-2201-04)
Knob (Bass, Treble)
Metallic cabinet Knob (Volume)
(K29-2506-14) x 2
{A01-1584-01) (K29-2767-04)
Panel ass’y
(A20-5361-02)
KENWOOD
sa
reat
Mic
jack
Nee
oer
Oe
(£1
1-0159-05)
Phone jack (Phones) Dressing plate (LED) Knob (Mic mixing)
(E11-0160-05) (BO3-2334-04) (K29-2737-04)
Binding post (GND) Screw terminal board (4P) Phono jack (2P) | AC outlet* — Power cord bushing
(NO8-01
28-35)
(E20-0455-05)
(E13-0297-05)
(EO3-)
(J42-0083-05)
Phono jack (3P)
(E13-0309-05)
Slide switch
Slid2 switch*
(S31-2113-05)
(S31 -2083-05) x 2
Phono jack (4P)
Rertangular
(E13-0497-05)
receptacle
(Et3-0411-05)
EY . ! AC 10 *
Phono jack (6x Phono jack (6P) ps eae
(E13-0621 omy 1 (E13-0621-05) |
Foot .? Phono jack (8P) Miniature phone jack*
(J02-0366-05) x 4 ©. (E13-0814-05) (E11-)
Fin
(J12-0094-05) x 2
‘
«
&>
* Refer to parts list on peage 34.

Kenwood A-71 Specifications

General

Type	Integrated Amplifier
Frequency Response	5Hz - 100 kHz
Signal-to-Noise Ratio	110 dB
Damping factor	100
Output	Speaker
Speaker load impedance	4Ω - 16Ω

Summary

FUNCTION

Front Panel Controls Overview

Overview of front panel controls including power, headphones, input selection, volume, balance, muting, and tone.

Special Function Switches

Details on DAT DIRECT and CD DIRECT switches for enhanced audio quality.

Microphone Input and Mixing

Explanation of the MIC jack and the MIC MIXING control for microphone input.

CIRCUIT DESCRIPTION

Audio Unit Component Functions

Details the function and operation of integrated circuits within the audio unit.

Control Unit Component Functions

Explains the function of components within the control unit (X11-2452-71).

Amplifier Unit Component Functions

Details components of pre-amplifier, sub, and main amplifier units.

Microprocessor IC Details

Terminal connection diagram and keymatrix connection for the microprocessor IC1.

Detector and Reception ICs

Details supply voltage detector (IC4) and remote control reception module (A1).

Selector IC Details

Details the CX7977 selector IC, its block diagram, and analog circuitry.

Motor Driver IC

Details the BA6109 motor driver IC, its block diagram, and power derating curve.

ADJUSTMENT/REGLAGES/ABGLEICH

Idle Current Adjustment

Procedure for adjusting the idle current using a DC voltmeter and specific terminals.