Sansui QRX 5500A QRX 7500A Service Manual

Page 2

This service manual is designed for service engineers to repair, adjust,
maintain and order the replacement parts of the QRX-SSOOA, QRX-7SOOA

correctly.

When ordering the parts, use the stock number and parts name speci-
fically referring to the Parts Location and Parts Lists.

For general usage and maintenance of the unit, please refer to the
Operating Instructions attached with the unit.

TABLE OF CONTENTS

Section Title

Page

1. SPECIFICATION. .
1-1. QRX-SSOOA ..........

1 2 QRX-7SOOA ................................ 4
2. BLOCK DIAGRAM .............................. 5
2-1. QRX-SSOOA . .. ....... 5, 6
2-2. QRX-7SOOA ... ....... 7, 8

3. ALIGNMENTS AND ADJUSTMENTS ............ 9
3-1. Regulated Power Supply Board Adjustment.
5'2. Level Meter Adjustment .....
3-3. Driver Circuit Board Adjustment
3-4. FM IF Alignment .......................... 11
3-5. FM Dial Calibration and RF Alignment ..11. 12
3-6. FM Signal Meter, Mono Distortion,

Tune Meter and Muting Adjustment .... ..12
3-7. MPX Alignment ........................ ..13
3-8. AM IF, Dial Calibration, RF and
Signal Meter Alignment ................ 13, 14
4. PARTS LOCATIONS AND PARTS LIST ........ 15
4-1. F4517 Tuner Circuit Board .............. 15.16
4-2. F-1515 Protector & Power Circuit Board . .17, 18
4-3. F-I488 Connector Joint Circuit Board ... . , .18
4-4. F-1470 Illumination Unit Circuit Board .. ..18
4-5. F-1485 Meter Circuit Board .19
4-6. F-1483 Protector & Power Circuit Board .20
4-7. F-15l6 Accessory Circuit Board .20
4-8. F1487 Volume Circuit Board. . .. 420
4-9. F4484 Tone Control Circuit Board .. ...21

4-10. F-2084 QS Vario-Matrix Circuit Board. . . .21, 22

Section Title Page
4-11. F-2048 Vario-Matrix Circuit Board ...... 23, 24
4-12. F-14B9 Mixing & Accessory Circuit Board . . . .24
4-13. F-ISI4 Driver Circuit Board .................. 25
4-14. F-I482 Driver Circuit Board ....... .26
4-15. F-2589 Equalizer 8t CD-4 Circuit Board ...... 27
4-16. F-1472 Equalizer Circuit Board .............. 28
4-17. F1486 Filter Circuit Board ...... .29
448. F-l490 De-emphasis Circuit Board .......... 29
4-19. Figures .................................... 29

5. THREADING OF DIAL CORD .................. 3O
6. OTHER PARTS ................................ 31
6-1. Other Parts (Top Side)/QRX-5500A ..31
6-2. Other Parts (Bottom Side)/QRX-SSOOA ...... 32
6-3. Other Parts (Front Side)/QRX-5500A .. . .33, 34
6-4. Other Parts (Front Side)/QRX-7500A .35, 36
6-5. Other Parts (Top Side)/QRX-7500A ... . .36
6-6. Other Parts (Bottom Side)/QRX-7500A ..37
7. PACKING LIST ................................ 37
7-1. QRX-SSOOA ........................... 37
7-2. QRX-7500A ..... . .37
8. ACCESSORY PARTS LIST ........... ..37
8-1. QRX-SSOOA , .. . .37
8-2. QRX-7500A . . . . . .37
9. SCHEMATIC DIAGRAM ......... ..38
9-1. QRX-SSOOA (TUNER SECTION) ....... ..38
9-2. QRX»5500A (AUDIO SECTION) .............. 39
9-3. QRX-7500A (TUNER SECTION) . ..40
9-4. QRX-7SOOA (AUDIO SECTION) .............. 41

9-5. QRX-7500A EQUALIZER & CD-4 SECTION. . . .42

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1. SPECIFICATIONS

1-1. QRX-5500A
AUDIO SECTION
POWER OUTPUT
Min. RMS, all channels driven, from 20 to 20,000HZ,
with no more than 0.5% total harmonic distortion
27 watts per channel into 8 ohms
LOAD IMPEDANCE ........ 8 ohms
POWER BANDWIDTH ...... 20 to 20,000HZ at or rated
min. RMS power output
and total harmonic distor-

tion
TOTAL HARMONIC DISTORTION
OVERALL (from AUX) ....Iess than 0.5% at or rated

min. RMS power output
INTERMODURATION DISTORTION
(70Hz: 7,000Hz:4:1 SMPTE method)

OVERALL (from AUX) Muless than 0.5% at rated min.
RMS power output
DAMPING FACTOR ........ 40 (an)

INPUT SENSITIVITY AND IMPEDANCE
(1,000Hz, for rated power output)
2-CHANNEL PHONO-I, 2. IZ.5mV 50k!)
(Max. input capability; 250mV at 0.5% distortion)
2-CHANNEL TAPE
PLAY Pin Jacks ....... 100mV 50k!)
REC/PLAY DIN Socket ..lUOmV SORQ

4~CHANNEL AUX ........ 100mV 50k!)
4-CHANNEL TAPE-1, 2

PLAY Pin Jacks ........ 100mV 50k!)
MIC (monophonic) ...... 2.5mV 10k!)

RECORDING OUTPUT
2-CHANNEL TAPE
REC Pin lacks .......... IOOmV
REC/PLAY DIN Socket ..30mV
4-CHANNAL TAPE-1, 2
REC Pin lacks tttttttttt 100mV
FREQUENCY RESPONSE (at 1 Watt Output)
OVERALL (from 4-CHANNEL AUX)
...................... 30 to 30,000Hz :I32d8
EQUALIZATION (RIAA curve)
...................... 30 to 15,000HZ i1,0dB
CROSSTALK (FUNCTION contrOIIZ-CH, 1,000HZ)
...................... better than 50dB
HUM AND NOISE (IHF)

2-CHANNEL PHONO ...... better than 70dB

4-CHANNEL AUX ........ better than 80dB
SWITCHES AND CONTROLS

BASS .................... +12dB, 712dB at SOHZ

TREBLE . . .. ,+12dB, 712dB at15,000HZ

LOUDNESS .............. +8dB at SOHZ

+3dB at 10,000HZ
LOW FILTER ............ 71OdB at SOHZ (6dB/oct.)
HIGH FILTER ............ -IOdB at 10,000HZ

SYNTHESIZER/DECODER . I ..

(6dB/oct.)

QS regular matrix system
with OS vario-matrx cir-
cuit,

TUNER SECTION

TUNING RANGE

SENSITIVITY (IHF) ..........
(DIN) ..........

88 to 108MHz
1.9,uV
1.1yv

(Max. input capability: 120dB)

SIGNAL T0 NOISE RATIO (m
CAPTURE RATIO (IHE). :- m
IMAGE REJECTION

ono)

better than 65dB
less than 2,0dB
better than 75dB

IF REJECTION .............. better than 90dB

SPURIOUS RESPONSE REJECT

SELECTIVITY

ION
better than 80dB
better than 60dB

TOTAL HARMONIC DISTORTION

Mono
Stereo
STEREO SEPARATION ......
FREQUENCY RESPONSE H,
ANTENNA IMPEDANCE

TUNING RANGE
SENSITIVITY (bar antenna)
IMAGE REJECTION
IF REJECTION .....
SELECTIVITY

OTHERS
POWER REQUIREMENTS
Voltage ..................
Consumption ............
DIMENSIONS

WEIGHT

' Design and specifications subject
improvements.

less than 0.3%

(less than 0.5%

better than 37dB

.30 to 15,000Hz :g;gds
.3000 balanced, 750

unbalanced

535 to 1,605kHz

.SOdB/m

better than 80dB

. better than 80dB

25dB

100, 120, 220, 240V 50/60HZ
140W (rated), 400VA (max)
594mm (23%) w

203mm (8) H

370mm (14%) D

21.6 kg (47.5 lbs) Net

24.8 kg (54.6 lbs) Packed

to change without notice for