Sony tc wr 681 service manual

Page 1

TC-WE425/WE525/
WR681

"'sEFiVIcE MA'NUA'L WM

TC-WE425/WR681

Canadian Model

TC- WE425

AEP Model

TC-WE525/WFI681

UK Model

TC- WE525

E Model
Australian Model

Photo: TC-WE425 TC'WE425/W3587
Chinese Model
TC-WE425
Dolby noise reduction extension manufactured under license Model Name Using Similar
from Dolby Laboratories Licensing Corporation Mechanism NEW
HX Pro originated by Bang & Oluisen DOLBY, the double~D Tape Transport DECK A TCM-230ASR1
symbol l1] and HX PFlO are trademarks of Dolby Laboratories Mechanism Type DECK B TCM-230ASR2
Licensmg Corporation.
SPECIFICATIONS
System
Recording system Frequency response (Dolby NR oil)
4-n'ack Zechannel Slcreo
Tape type
Fast-winding time (approx) -_
100 sec. (wim Sony 060 cassette) Type 1 laps, Sony Type 1 30-16000 Hz (:3 dB. IEC),
(NORMAL) 20-17,000 Hz (:6 LIB)
Bias ---
AC bias Type II tape. Sony Type II 3017.000 Hz (:3 dB, IEC),
(HIGH) 2048.000 Hz (:6 dB)
SignaHo-noise ratio (at peak level and weighted with Dolby NR ofl) -
Type 1 [399, Sony Type 1 (NORMAL); 55 as Type IV rape. Sony Type IV all-19,000 Hz (:3 dB, TEC),
Type 11 tape, Sony Type 11 (HIGH): 57 dB (METAL) 2040,0110 Hz (:6 dB),

Type IV tapev Sony Type IV (METAL): 58 dB
Wow and flutter

S/N ratio improvement (approximate values) 3 0.15% W. Peak (IEC)
With Dolby B NR on: 5 dB at 1 kHz, 10 dB at 5 kHl (79 W. RMS (NAB)
With Dolby C NR on: 15 dB at 500 Hz, 20 dB at 1 kHz 1 0.2% W Peak (DIN)

Harmonic distortion
0.4% (with Type I tape, Sony Type I (NORMAL):
160 nWb/m 315 HZ. 3rd HD.)
1.8% (with Type [v tape, Sony Type IV (METAL):
250 nWb/m 315 Hz, 311! HD.)

- Continued on next page -

STEREO CASSETTE DECK
S ONE

MICROFILM

Page 2

Inputs

Line inputs (phono jacks)
Sensitivity : 0.16 V
Input impedance : 47 kilohrns

Outputs
Line outputs (phono jacks)
Rated output level 1 0.5 V at a load impedance of
47 kilohms
Load impedance : Over 10 kilohms
Headphones (stereo phone jack) (TC-WE425IWE525 only)

Output level : 0.25 mW at a load impedance of
32 ohms

General

Power requirements

Where purchased Power requirements

US. Canadian 120V AC. 60 Hz

AEP, UK, Chinese 220 7 230 V AC, 50/60 Hz

Ausualim 240 V AC, 50/60 Hz

E. Singapore, Malaysia 120/220/230 , 240 V AC, 50/60 Hz

Power consumption
18 W

Dimensions (approx.) (w/h/d)
430 x 120 X 290 mm (w/hld)
(l7x4314x ll 3/sin.)
including projecting pans and conu'ols

Mass (approx)
4 kg (s lbs 13 oz)

Supplied accessories
Audio connecting cords (2 phonn plugs - 2 phonn
plugs) (2)
CONTROL A1 cord (supplied for Canadian models
only) (I)

Design and specifications are subject to change without
notice.

SAFETY-RELATED COMPONENT WARNINGII

COMPONENTS IDENTIFIED BY MARK A OR DOTTED LINE
WITH MARK A) ON THE SCHEMATIC DIAGRAMS AND IN
THE PARTS LIST ARE CRIflCAL TO SAFE OPERATION.
REPLACE THESE COMPONENTS WITH SONY PARTS WHOSE
PART NUMBERS APPEAR AS SHOWN IN THIS MANUAL OR
IN SUPPLEMENTS PUBLISHED BY SONY.

SAFETY CHECK-OUT

After correcting the original service problem, perform the follow-
ing safety check before releasing the set to the customer:

Check the antenna tenninals, metal trim, metallized knobs, screws,
and all other exposed metal parts for AC leakage. Check leakage as
described below.

LEAKAGE TEST

The AC leakage from any exposed metal part to earth ground and
from all exposed metal parts to any exposed metal part having a
return to chassis, must not exceed 0.5 mA (500 microampers).
Leakage current can be measured by any one of three methods.

1. A commercial leakage tester. such as the Simpson 229 or RCA
WT-54OA. Follow the manufacturers instructions to use these
instruments.

2. A battery-operated AC milliammeter. The Data Precision 245
digital multimeter is suitable for this job.

3. Measuring the voltage drop across a resistor by means of a VOM
or battery-operated AC voltmeter. The limit" indication is 0.75
V, so analog meters must have an accurate low-voltage scale.
The Simpson 250 and Sanwa SH-63Trd are examples of a pas-
sive VOM that is suitable. Nearly all battery operated digital
multimeters that have 21 2V AC range are suitable. (See Fig. A)

To Exposed Metal
Parts on Sat

AC
voltmeter
(0.751)

0.15;:

[g 1.51th /
'.___I

'-' Eanh Ground

Fig. A. Uslng an AC voltmeter to check Ac leakage.

ATTENTION AU COMPOSANT AYANT RAPPORT
A LA SECURITEI!

LES COMPOSANTS IDENTIFIES PAR UNE MAROUE A SUR LES
DIAGRAMMES SCHEMATIOUES ET LA LISTE DES PIECES SONT
CRITIQUES POUR LA SECURITE DE FONCTIONNEMENT. NE
REMPLACER CES COMPOSANTS OUE PAR DES PIECES SONY
DONT LES NUMEROS SONT DONNES DANS CE MANUEL OU
DANS LES SUPPLEMENTS PUBLIES PAR SONY.

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