Technics SUV 505 Service Manual

Page 1

ORDER NO. 808301 2365(3

Service Manual

,Stereo Integrated Amplifier

SU-V505

[E]. [EK].[EF].[EBI. [EH].[Ei].
[XA],[XL].[PA].[PE].[PC]

SU- V5O5(K)

[E] [EK]. [EB] [EH] [Ei] [XA]
[PC]

Areas

" [E] is available in Scandinavia and Switzerland.

' [EK] is available in United Kingdom.

" [EF] is available in France.

[EB] is available in Belgium.

" [EH] is available in Holland.

[Ei] is available in Italy.

[XA] is available in Southeast Asia, Oceania, Africa,
Middle Near East and Central South America.

W

The cabinet and front panel are available in black color and
silver types.

[XL] is available in Australia.
" [PA] is available in Far East PX.
' [PE] is available in European Military,

\ The black type model is provided with [Kl in the Service Manual.

[PC] is available in European Audio club. J

. . .
SpeCIflcatlons (Specifications are subject to change without notice for further improvement.)

Power bandwidth
both channels driven, *3 dB
5 HZ~50 kHz (40, T.H.D. 0.03%)
5 Hz~60 kHz (80. T.H.D. 0.02%)
0.6 mV
30 (4Q), 60 (8Q)

(DIN 45 500)

l AMPLIFIER SECTION
Residual hum and noise

20 H1~20 ka continuous power output Damping lactor

both channels driven 2 X 60W (40) Input sensitivity and Impedance
2 X 60W (80) PHONO MM 25 I'nV/47kQ
40 Hz~16 kHz continuous power output MC 200 uV/ZZOQ
bélh channels driven 2 X 60W (40) TUNER, AUX/CD/VIDEO 150 II'lV/22kQ
2 X 60W (80) TAPE 1 150 mV/22kQ
1 kHz continuous power output TAPE 2 150 mV/22kn
both channels driven 2 X 50W (40) PHONO maximum input voltage (1 kHz, RM5)
2 X 60W (50) MM 170 mV
Total harmonic distortion MC 15 mv
rated power at 20 Hz~20 kHz 0.03% (40) SIN
0.004% (30) rated power (40)
rated power at 40 Hz~16 kHz 003% [40) PHONO MM 78 dB (83 dB, IHF, A)
0.004%.(80) MC (250 uV) 64 dB (65 dB, IHF. A)
rated power at 1 kHz 0.007% (40) TUNER, AUX/CD/VIDEO, TAPE
0.003% (80) 91 dB (IHF, A: 102 dB)
hall power at 20 Hz~20 kHz 0.004% (80) -26 dB power (40)

hall power at 1 kHz 0.002% (80) PHONO MM 71 dB

726 dB power at 1 kHz 0.01% (40) MC 63 dB

50 mW power at 1 kHz 0.01% (40) TUNER, AUX/CD/VIDEO, TAPE 72 dB
Interrnodulation distortion 50 mw power (40)

rated power at 250 Hz: 8 kHz34z1, 40 0.03% PHONO MM 68 dB

rated power at 60 Hz: 7 kHz=4:1, SMPTE, 80 0.01% MC 62 dB

TUNER. AUX/CD/VIDEO, TAPE 68 dB

Pun-sonic Tokyo
Matsuthlu Electric Industrial Co., Ltd.
I-2. 1-chome, Shiba-koen. MinatoAku, Tokyo 105 Japan

Matsushita Electric Trading 00., Ltd.
P.O. Box 288. Central Osaka Japan

Technic

Page 2

Frequency response
PHONO RIAA standard curve
$0.8 dB (30 Hz~15 kHz)
TUNER, AUX/CD/VIDEO, TAPE 5 Hz~140 kHz (-3 US)
+0 d8, *02 dB (20 Hz~20 kHz)

Tone controls
BASS 50 Hz, +10 dB~ 10 dB

TREBLE 20 kHz, +10 dB~ -10 dB
Subsonic filter 30 Hz, *6 dB/oct.
Loudness control (volume at -30 dB) 50 Hz, +9 dB
Output voltage and impedance

REC OUT 150 mV
Channel balance, AUX/CD/VIDEO 250 H1N6,300 Hz i1 dB
Channel separalion, AUX/CD/VIDEO 1 kHz 63 dB

Headphones output level and impedance 520 mV/aaoo
Load Impedance
MAIN or REMOTE

MAIN and REMOTE

4Q~160
80~160

. GENERAL

Power consumption 370W
Power supply

For continental Europe iExcept for United Kingdom)

AC 50 Hz/GO Hz, 220V

For Australia AC 50 Hz/6O Hz. 240V

For others AC 50 Hz/60 Hz. 110V/120V/220V/240V

Dimensions (WXHXD) 430 X 109 X 290 mm

(16-15/16" X 4-9/32"><11»13/32)

7.6 kg

(16.8 lb.)

Weight

Note:
Total harmonic distortion IS measured by the digital spectrum
analyzer (HP. 3045 system),

I CONTENTS

SAFETY PRECAUTION . . . .
LOCATION OF CONTROLS . . . . .
PROTECTION CIRCUITRV .........
BEFORE REPAIR AND ADJUSTMENT . .
MEASUREMENTS AND ADJUSTMENTS .
TECHNICAL INFORMATION ........
OPERATION OF lcu CONTROLLER . . .

BLOCKDIAGRAM ...............

I SAFETY PRECAUTION

Before servicing (such as replacement of components), unplug the power supply cord to prevent an electric shock.
Use only manufacturers recommended components for safety, Check condition of power cord and replace if wear or

I.
2.

3.

o
1
2
3

damage is evident.

Page

CIRCUIT BOARDS AND WIRING
CONNECTION DIAGRAM ......... . . . . 17,18
PRINTED CIRCUIT BOARDS . . . . . . . . 19" 22
SCHEMATIC DIAGRAM .......... 23 ~ 28

FUNCTION OF TERMINAL (ICO CONTROLLER IC702) ..... 28
RESISTORS & CAPACITORS ........... . . . .

REPLACEMENT PARTS LIST
EXPLODED VIEWS .......

After servicing, be sure to restore the following to the condition in which they were originally installed

(ll the lead dress and

(2) insulation barriers, insulation papers, shields and the like
. Before returning a serviced apparatus to a customer, make the following insulation resistance test to prevent a customer

from being exposed to a shock hazard.

Insulation resistance test (See figure below.)

. Unplug the power supply cord and connect a jumper wire between the two prongs on the plug.
. Turn on the power switch of the apparatus.
. Measure the resistance value (with an ohmmeter) between the jumpered AC plug and each exposed metalic cabinet part on

the apparatus, such as screwheads, antenna, control shafts, handle brackets, etc.
The reading should be as shown in figure below. In case a measurement is outside of the limits specified, there
is a possibility of a shock hazard, and the apparatus should be repaired and rechecked before it is returned to a customer.

Tuner, Receiver etc.

Antenna
terminal \

Exposed
metal
part

Ohmmeter

3MQ

Turntable, Amplifier etc.

Exposed
metal
pan

Ohmmeter

R = nearly m

where, H: resistance value

i
l.
é

Page 8

I TECHNICAL INFORMATION

1. Description of Computer drive system
Technics New Class A amplifier circuitry eliminates switching and crossover distortion To further improve fidelity a

computer drive" circuit has been incorporated to eliminate transient distortion in music signal reproduction_

Smooth crossover required
for low distortion.

0 Power transistor idling current (Ice)

The idling current through the power transistors is adjusted

so that crossover distortion is minimized when switching .
NPN Transistor

from the NPN transistor to the PNP transistor in a com- ______ ___.___l__.__-___

plimentary design (Fig. 12). PNP Transistor \ [I
If Ice is not adjusted properly. distortion will result as in \
Fig. 13
[Fig]. 12]
® lco is too low (5) Ice is too high © loo is optimum
\ \
\ \ \ t
\ \ _ § _____
- - - \ \ \ - - - - - x
\
\ \
\ \
\
Distortions Distortions Distortions
-> Power -> Power -> Power
Relationship between idling current level and cross-over distortion,
[Fig. 13]
0 Idling current and bias current Idling current (Ice)

Idling current is determined by the bias voltage (Vbl ot
the bias circuit and the VBE of each power transistor
(Fig. 14). The VBE varies according to the temperature of
the transistor.- This temperature varies instantaneously
with the music signal. Unfortunately, with current designs,
these instantaneous fluctuations cannot be detected due to

the placement of the thermal sensor and the slow tem- g
perature change of the heat sink. Attempts have been made Bias _§
. u

to include a thermal sensor as part of the output power "899 3 To maker
'6:

packs However, most power packs do not include a thermal
sensor. Also, this method does not work if discrete com»
ponents are used We are still faced with the problem of
stable bias operation and fast response to abrupt changes
in temperatures

RE

PNP
Vb-(Vea * VBE2
2R5

Ico =

[Fig. 14]