Kenwood KXW 891 Service Manual

Page 1

STEREO DOUBLE CASSETrE DECK KEN V
KX-W891/W6030 WOOD
SERVICE MANUAL

EE $199141 PRINTED IN JAPAN

851-4278-10(813678

KX-W891

. sene
Cassette lid Metallic cabinet Knob (EJECT) Panel (133:9, ass'y

(A53-1282-04) (A01-1937-01) iK29-4129-04) (Am-004301) (Asa-128503)

immwmzmlmcwml
L been; , ,Mhmwul
F
. Knob (PLAY) Knob(REC BALANCE/LEVEL) Knob (PLAY)
(K29-4141-04) (K29-4130-04) x2 (K29-4141-04)
Cassette holder ass'y Escutcheon Knob (TAPE CONTROL) Escutcheon
(A53-1283-03) (807-1989-04) (K29-4134-02) (807498603)
Phone jack Miniature phone jack Slide switch
(E13-0445»05) (E11-0188-05) (831-2131-05)

T Power cord bushing

(J42-0083-05)
Foot AC power cord'
(JO2-0366-15) ><4 (E30-)

Refer to parts list on page 15

The shaded parts i * on the circuit diagram and on the printed circuit board
are different from the original manual.

This manual is applied the serial No. of KX-W89l (10400001) and KX-W6030
(10300001).

Page 11

KX-W891/W6030

CIRCUIT DESCRIPTION

Dual-channel electronic volume and balance control
Outline

The M51132L Is an lC for electronically Controlling the
volume and balance in a dual-channel audio system. It IS
housed in a 14-pin molded plastic zigzag inline package,
and supports both independent volumen control of the
left and right channels, and ganged volume control with
balance control, Control is effected by varying the applied
DC voltage.

Pin arrengement (top)

FIL @ @ NC
GND @ a MAS
P's @ a BAL

P 5 © (:3 MODE
OUT @ e N

Block diagram

control

1

Volumelvolume 1 Balance/volume 2 Control mode
selection

17*?

control

Input 1
INPUT

Control mode selection

circuit

BUF1

I?

Control voltage control

circuit

VCA1.

Reference power

Power supply $07-

Output 1 Filter

supply circuit
UTPUT
I BUFl

noise when the
pass- through switch

;14) Input 2
OUTPU
Output 2

Ground Reducing shoc-®-k Pass- -Ihrough/VCA
selection switch

INPUT 17
T BUFZ
_¥r
VCAZ

I
I
: Pass- -through switch
:
I

mt!-
Pin functions
Pin No. Name Use 5Vd
_ DC volt-go
® Power supply Apply 8 to 15 VDC lRated voltage 12 V)
(Z I Input 1 1 Maximum permissmle input 34 Vrms (standard) 5 5V
7 ,7, i - ,
g) Output 1 i i 7 , _ 48V 7
@ Relerence power supply output Maximum output current 10 inA (staiidardl A shortrcircuit prevention Circuit is 5 2V
incorporated
(9 Filter ,_.,,e, > W 77* 12V
@ No connection Can be used relay Wiring for grounding i ,_
(2) Ground 7 fl ,
C8) Volume/volume 1 control On application of 0 to 5 2 VDC. controls the channel 1 and channel 2 volumes in
tandem or the channel 1 volume
62 Reducmg shock noise when the The switching noise is reduced by provtding a time constant [Tl and slowly swnching 5 2 v to,
pass-through swttch is closed between pass-through and VCA The time constant IS determined by an external pass through 0 V
capacuor (C) T (secl : 12 x C X 20k lorVCA
® Balance/volume 2 control On application ol 0 to 5 2 VDC, controls the balance or the channel 2 volume 4
® Pass-through/VCA swrtch 0 v VCA
52 V Input signal is passed through and output 657 is
@ Control mode selection 0 V Pin 8 Channel 1 volume
Pin 10 Channel 2 volume
52 V Pin 8 Channel 1 and 2 volumes
Pin 10 Balance
(3 Output 2 4 8V
@ Input 2 r MaXImum permissmle input 3 4 Vrms (standard) 5 5V

12

99

I-