Sony TC-WR990 User Manual

TC-WR521/WR990
SERVICE MANUAL
US Model
Canadian Model
TC-WR521/WR590
AEP Model
UK Model
E Model
TC-WR590
Photo : TC-WR590
SPECIFICATIONS
4-track 2-channel stereo
Approx. 90 sec. (with Sony C-60
Recording system
Fast winding time
cassette)
Bias AC bias
Signal-to-noise ratio (at peak level)
Cassette Type IV Type II Type |
(Dolby NR (Sony HF-S)
OFF)
(Sony Metal- | (Sony UX-S)
Select/S)
| 58dB |
57 dB
Measured at peak level weighted without NR. The S/N is
improved by about 15 dB at 500 Hz and by about 20 dB
about 1 kHz with Dolby-C NR on, and by 5 dB at 1 kHz and
by 10 dB about 5 kHz with Dolby-B NR on.
Harmonic distortion
0.4% (with Sony Type I, 160 nWb/m,
315 Hz, 3rd H.D.)
1.8% (with Sony Type IV, 250 nWb/m,
315 Hz, 3rd H.D.)
Frequency response (Dolby NR OFF)
WR8521
30-18,000 Hz ( + 3dB, IEC)
30-13,000 Hz (+ 3dB, (—4dB) recording)
WR521
(Sony Metal-
Select/S)
WR521
WR5s0
+0.14% W.Peak (IEC)
0.08% W.RMS (NAB)
+0.19% W.Peak (DIN)
MICROFILM
Model Name Using Similar Mechanism | TC-WR520/WR570
DECK A| TCM-190RA12C
re-wnses [DESK
DECK B| TCM-190RB22C
DECK A| TCM-190RA12C
DECK B| TCM-190RB12C
Tape Transport
Machanism Type
inputs
Line inputs | Sensitivity 0.16 V
(phono jacks) Input impedance _—| 47 kilohms
Outputs
Line outputs Rated output 0.5 V ataload
(phono jacks) level impedance of
47 kilohms
Load impedance | Over 10 kilohms
Headphones Output level 1 mW ata load
(stereo phone jack) impedance of
:(WRS590 only) 32 ohms
— Continued on page 2 —
Dolby noise reduction manufactured under license from
Dolby Laboratories Licensing Corporation.
“DOLBY” and the double-D symbo! 9 are trademarks of
Dolby Laboratories Licensing Corporation.
STEREO CASSETTE DECK
SONY.

Sony TC-WR990 Specifications

General

Track System	4-track, 2-channel stereo
Tape Speed	4.8 cm/s
Motor	DC Servo Motor
Total Harmonic Distortion	0.8%
Type	Double Cassette Deck
Wow and Flutter	0.07%
Input	Line In
Output	Line Out
Dimensions	430 x 120 x 300mm

Summary

Technical Specifications

Performance Specifications

Details recording system, fast winding time, signal-to-noise ratio, harmonic distortion, frequency response, and wow and flutter.

Service Manual Structure Overview

Section 2: Disassembly Procedures

Details procedures for disassembling the front panel, mechanism, motor, and head.

Section 3: IC Terminal Explanations

Section 4: Adjustments

Covers mechanical and electrical adjustment procedures for optimal performance.

Section 5: Diagrams

Includes block diagrams, printed wiring boards, and schematic diagrams.

Section 6: Exploded Views

Provides exploded views of the chassis, front panel, and mechanism sections.

Section 7: Electrical Parts List

Safety Checks and Precautions

AC Leakage Testing Procedure

Outlines methods for testing AC leakage current from exposed metal parts.

Safety-Related Component Identification

Highlights components critical for safe operation and replacement.

Mechanical Adjustment Procedures

Mechanical Adjustment Precautions

Torque Measurement Methods

Electrical Adjustment Procedures

Record/Playback Head Azimuth Adjustment

Step-by-step guide for adjusting the record/playback head azimuth for optimal performance.

Playback and Speed Calibration

Playback Level Adjustment Process

Steps for calibrating playback output levels to specified values.

Tape Speed Adjustment Process

Steps for adjusting the tape speed for accurate playback.

Specific Calibration Procedures

Bias Consumption Current Adjustment

Details the procedure for adjusting bias consumption current.

Record Level Adjustment Procedure

Outlines the steps for setting the record level.

System Diagrams

Block Diagram Overview

Schematic Diagrams - System Control Section

System Control Schematic Details

Schematic Diagrams - Audio Section

Audio Section Schematic Details

Exploded Views - Chassis Section

Chassis Section Parts Identification

Exploded Views - Front Panel Section

Front Panel Section Parts Identification

Exploded Views - Mechanism Section 1

Mechanism Section 1 Parts Identification

Exploded Views - Mechanism Section 2

Mechanism Section 2 Parts Identification

Electrical Parts List - Audio Board

Audio Board Resistors and Capacitors

Electrical Parts List - System Control