Technics SL 1401 Service Manual

Page 1

ORDER NO SD7803- 1335

Service Manual

QUARTZ

Direct Drive Automatic Turntable System

SL-1401 (MC)

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I The model SL-1401 (MCI is available in Canada only.

SPECIFICATIONS

General
Power supply:

Power consumption:
Dimensions:

(H x W x D)
Weight:
Turntable section
Type:

Drive method:
Motor:

Drive control method:

Turntable platter:

Turntable speeds:
Starting torque:
Braking system:
Speed fluctuation due

to load torque:
Speed drift:

Specifications are subject to change without notice for further improvement,

AC1 20V, 50 or 60 HZ

9.5W

12.5 x 45.3 x 36.9 cm
4-15/16 x17-3/4 x14v9/16
9.3 kg (20 lb.)

Automatic turntable, Auto
return, Auto stop.

Direct drive

Brushless DC motor
Quartz-phase locked control
Aluminum dieecast

Diameter 33 cm (13 Inches)
Weight 2.2 kg (48 lb.)
Moment of inertia 310 kg-cm2
(106 Ib-inz)

33-1/3 rpm and 45 rpm

1 kg-cm(0.91b-in)

Electronic brake

0% within 0.9 kg-cm (0.81b-in)

Within t0.002%

Wow and flutter:

Rumble:
Tonearm section

Type:

Effective length:
Overhang:

Tracking error angle:

Offset angle:
F r iction:
Effective mass:

Stylus pressure
adjustment range:

Applicable cartridge
weight range:

Headshell weight:

0.025% WRMS (JIS C5521)
i0.035% peak (IEC 98A
Weighted)

~73 dB (IEC 98A Weighted)
750 dB ((EC 98A Unweighted)

Universal tonearm Gimbal
suspension 8" shaped tubular
arm Static balanced type

230 mm (9-1/16 inches)

15 mm

+3° at the outer groove of 30 cm
(12") record

+1° at the inner groove of 30 cm
(12") record

215°

Less than 7 mg (lateral, vertical)
22 g (with 6 g cartridge weight,
1.75 g stylus pressure)

0'39
57119
9.5g

Weights and dimensions shown are approximate.

Technics

Panasonic Company

Division of Matsushita Electric
Corporation of America

One Panasonic Way, Secaucus,
New Jersey 07094

Panasonic Hawaii, Inc.

320 Waiakamilo Road, Honolulu.

Hawaii 9681 7

Matsushita Electric of Canada Ltd.

40 Ronson Drive, Rexdale,
Ontario, Canada M9W1BS

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I PARTS IDENTIFICATION

Phono cables

AC power cord

Output terminals

11; Ground wire lE/GND)

Hinge

Balance weight

Anti-skating control knob

Arm clamp

Motor shaft (Center spindle)

Turntable mat

Strobe illuminator

Power switch

Stylus pressure ring

Arm rest

Cueing lever

Locking nut

Stan/Stop button

Headshell

Speed select buttons

I FEATURES

Three kinds of high integration lC's.

In high accuracy quartz control, advanced electronic circuit
technique and IC formation technique are required.
Technics employs the three kinds of high density lC, i.e., IC
for frequency divider (DN860) adpoting IZL and ECL. IC
for phase and speed control (AN660), and IC for driving
(AN640), and thus has produced a high accuracy quartzA
locked turntable with a less than i0.002% speed drift. (In
conditions for normal use in which the temperature is
stable, the drift is only approximately t0.00001%)

Double isolator with particular emphasis on prevention of
acoustic feedback.

Rotational accuracy may be said to have reached the
ultimate with the superior quartz control system. in order
to maximize such high performance, the double isolator
(double-isolated vibration-damping mechanism), unique in
Technics has been employed, while the turntable and
tonearm are installed on a base weighted by the integrated
construction of the main base and bottom cover, with the
entire base floating in stable equilibrium with respect to the
main turntable base through special isolators. Additionally,
the main turntable base is also provided with an isolator
superior in vibration damping characteristics. The com-
bined effect obtained from the two kinds of isolators
results in extremely superior vibration cut-off and absorp-
tion characteristics against external vibrations and local
resonance from the direct sound pressure of the speakers,
the floor etc. giving a marked improvement in prevention of
howling.

Turntable platter

Fig. 1

Highly sensitive gimbal suspension system.

With the high precision pivot bearings employed for the
horizontal and vertical journals of the tonearm, in concert
with the adoption of the gimbal suspension system, a high
sensitivity arm of less than 7 mg friction has been attained,
thus making it possible to fully display the performance of
the high compliance cartridge.

Motor construction unique to Technics in which the motor
rotor is integrally connected to the turntable platter.

The large, heavy weight class precision aluminum diecast
finished turntable has the remarkable moment of inertia of
310 kg-cmi.

Precision aluminum diecase cabinet unique to Technics is
used.

Superior load fluctuation characteristics.

By using the high precision quartz phase-locked control
system and high-torque motor, stable load fluctuation
characteristics are obtained, with no speed change even
at a stylus pressure of 180 9,

Smooth braking is achieved with the fully electronic system
which also makes possible almost instantaneous speed
change.