Hitachi HT-L55 - User Manual

No.
347 EGF
HT-t55
CONTENTS
.
INHALT' SOMMAIRE
SAFETY PRECAUTION
The following
precautions
should
be observed
when
servicing.
1.
Since
many
parts
in
the unit have
special safety
related characteristics,
always use
genuine
Hitachi's
replacement
parts.
Especially
critical
parts
in the
power
circuit block should
not be replaced with other makers.
Critical
parts
are marked with A in the
circuit diagram.
,^\
SPECIFICATIONS
Type
Platter
Motor
Speed
Speed
change system
s/N
Wow
and flutter
Speed deviation
Speed drift
(for
timel
lfor
temperaturel
Tonearm
Effective length 95 mm
Tracking error +0.1"
Lead wire capacitanca 140
pF
2-speed
quartz
controlled
direct
drive fully
automatic
turntable
Aluminum alloy dre-cast, 296 mm
outer
diameter
Brushless, Slotless, Coreless DC
servo
"Unitorque"
motor
2-speeds;33-1/3 and 45 rpm
Electronic
change-over system
78 dB
(DrN-B)
0.025%
(wRMS)
oo03%
O OO37olhour
o.0o3%
(5
-
35'C)
Linear tracking tonearm
Cartridge
Frequency
fesponse
Output voltage
Channel difference
Channel s€paration
Tracking force
Weight
Stylus tip
Power source
Power consumption
Dimensions
Weight
the unit to ascertain
that
Dual magnet type
(MT-33)
10
-
25,000 Hz
3.5 mV at 1 kHz,
50
mm/sec.
ldBatlkHz
23 dB aî
1 kHz
1.25
+0259
59s
Diamond stylus
(DS-ST33)
'I
20V 60 Hz for U S A and Canada
sîandard
22OV 50
Hz for
Europe standard
240V 50 Hz for
U
K
and
Australia
standard
11O-12O/22O-240V 50/60 Hz forAsian
and
Latin American countries
15 watts
315
(W)x83 (H)x
31 5
(D)
mm
45ks(1Olbs)
2. Betore returning a repaired unit to the
customer,
the service
technician must
thoroughly
it is
completely safe
to
operate
without
danger
of electrical shock.
l,vtr I Ett I D. iltt-rALr' Dr.rrvilYrArrrE
SPECIFICATIONS'
TECHNISCHE DATEN,
CARACTÉRTSTTOUE TECHN1OUES..................
.....
1,2
FEATURES.
BESONDERHEITEN. CARACTÉNISIOUCS.... T, Z
SERVICE
POINTS
.
WARTUNGSPUNKTE.
POINTS D'ENTRETIEN.
ADJUSTMENT
.
EINSTELLUNGEN
.
RÉGI.AGE. .................... 6,
7
BLOCK DIAGRAM
.BLOCK
SCHEMA.
scHEM4.........
..........................
I
REPLACEMENT
PARTS LIST' ERSATZTEITLISTE
.
TABLEAU
DES PIECES....
.....
9,
îO, 15
PRINTEO WIBING
BOARD
'
PRINTPI.ATTEN
.
PLAN DE 8ASE................
................................. I 1
CIRCUIT
DIAGRAM.SCHATTPI.AN
.PLAN
DE CIRCUIT..... 12
EXPLODED VIEW
.
AUSEINANDERGEZOGENE
DARSTELTUNG.VUEÉCLATÉE
........................î3,14
DESCRIPTION
OF THE NEW COMPONENT'
BASCHREIBUNG.
DER NEUEN KOMPONENT.DESCRIPTION DE
I-A
NOUVELLE COMPOSANT..........
1
2.
3.
Low-mass,
dynamic balance linear tracking
tonearm
Disk
jacket
size
for
easy
installation
anywhere
Slimly
designed
Unitorque motor
Ouartz control
(quartz
lock PLL
servol
Repeat
play
from
any
position
on disk
{program
repeat)
Timer staÉ from
any
position
on
the
Cisk
4.
5.
6.
SPECIFICATIONS AND PARTS
ARE SU&'ECT
TO
CHANGE FOR IMPROVEMENT.
DIRECT
DRIVE
AUTÍIMATIC
TURNTABLE
October
î
982
TOYOKAWAWORKS

Summary

Service Points

Removing Control PWB

Procedure for removing the Control Printed Wiring Board.

Removing Microswitch (Power Source)

Procedure for removing the microswitch related to the power source.

Removing DD Motor

Procedure for removing the Direct Drive (DD) motor.

Removing Linear Mechanism

Procedure for removing the linear tracking mechanism.

Removing Pick-up

Procedure for removing the pick-up assembly.

Removing Wire

Procedure for removing internal wiring.

Replacing Cartridge

Instructions for replacing the audio cartridge.

Replacing Stylus

Instructions for replacing the stylus (needle).

Adjustments

Quartz Lock Phase Adjustment

Procedure for adjusting the quartz lock phase for stable rotation.

Linear Tracking Adjustment

Procedure for adjusting the linear tracking mechanism.

Stylus Lowering Position Adjustment

Procedure for adjusting the stylus lowering position.

Return Sensitivity Check

Procedure for checking the tone arm return sensitivity.

Description of New Component

Pin Description (HD38755 A59)

Detailed description of each pin for the HD38755A59 microcomputer.

Hitachi HT-L55 Specifications

General

Drive method	Direct drive
Platter	Aluminum die-cast
Tonearm	Static balance type
Cartridge	Moving magnet
Frequency response	20Hz to 20kHz