Sansui G 301 Service Manual

Page 2

6-3500/301

6-4500/401

SPECIFICATIONS

(3-4500/401
Audio union
Power autpur
Mill. RMS, both channels driven, from 20 to 20,000 Hz, with no
more than 0.1%ioral harmonic distortion.
#0 watts perehannel into 3 ohms
Load impedance . , . . a ohms
Total harmonic dislortion
............. less lhifl 0.1% itor below rated rnirl.
RMS power DUKPlll
lnrerrnodulariondmorrion (70 N1: 7 kl-iz- - 4:1 SMPTE method)
. Iessrnan 01%
Frequency response (at 1 watt)
. .. .. liotosoooohzolds ads
(mono)
. +0.5 as -:l.s an (ac to 15,000 Hz)
, approximately 30 at eohm
load
lnpursensirivityana lmpedahfiefl kHz Iorraled pnwerourpux)
PHDNO . . . 2. Sme kilohms
(Max. inputeapahil y, 200 mV ail kHz, lessthan0.5%toul
harmonic dislorllarl]
Aux, TAPE ,
MIC
Output level ll kMxl
TAPE REC lvrniack) . iso mVIA'l kilohms
Channel separation (l kHz, ai rated power output)

Darnpi g akin}

. lso «iv/47 kilnhms
, 8 mVI'lO kilohrns

Hum and noise isnorrcircuil, A network)

PHONO .

Aux..... .9Sda
Controls

BASS ,,,,,,,, :IO aalso Hz)

TREBLE MG dBilOka)

Louonzssi 'aoaa) 7 dBat 50 Hz
5 as at 10 kHz

FM section
Tuning range ....... es in ice MM:
Usable semiriviiy
Mona ll-tF .. . Il,oaef(l.9suvi
DlN.1.7 uv
Stereo |Hf . 19.0 dBf
50 dB Quitting wnstlivilY
Mono 5 dB!
Stereo . 33 dB!
Signal to noise ratio (ar 55 earl
Morin . , I 13
Stereo . . GE dB
Distortion in as
Mono .......... less than 0. E at 100 Hz

less (hm 0.15% at man Hz
less than 0.25% at 6.000 Hz
Stereo .......... less than 0.3% at 100 Hz
less rhan 0.25% 111,000 Hx
less than 0.3% at 6,000 tiz

Capture ratio . . 1.3 as
Image response ratio . as an [at as Mi-ix)
Spurious response rat . to as (I! 93 MHz)
Srereu separation ..... 30 an ar inn H1

an as 1.000 Hz

25 as at rooou N1
Frequency response , , 30m is,ooo Hz onsaa -1.oae
Antenna input impedance

. . . . . , , . 300 ohms balanced

75 ohms unbalanced

AM section
Tuning range ....... sao Iol ,500 kHz
Usable sensitivity (Bar antenna)

.............. so dB/m (300 uv/ml
Seleczlvily (:10 kHz) as an

Signal to noise ratio , . . 46 dB
Power requlrcments
Power voltage ...... l0l],17£l,220 2w v {so/so H1)

l20 V(Usable no ~130V)
so Hz (for u s A and Canada only)
Power eonsumprlon
Rated consumption . 115 watts Ms VA

Dimensions ..... . 4:3 mm li7-lllé"]w
153 mm (oi/ls") H
354 mm m) D

Weight ........... u min res) ner
9.5 kt 120.9 lbs) paekea

rHoNo . , better than 50 dB

AUX bmenhm 50 dB Alternate channel selectivity (ar 400 kHz) Design and specifications subieer ro change without notice

.............. sods ' forlmprovemenu.

1. OPERATIONS

Pop-noise preventive circuit

In order to prevent the annoying pophoise to the loudspeakers at
turning the power of the amplifier ON, the pop-noise preventive cir-
cuit adopted in the 6-4500/401 is the combination of the conven-
tional driver-voltage delay type used in the power supply (rectifier)
circuit and the NF delay type pop-noise preventive circuits. The
configuration of NF delay type pop-noise preventive circuit is
shown in Fig. l.

in this circuit, the switching (ON-OFF) of the transistor TR05 is
made by the time constant of the capacitor C40 and resistor R88.
Thereby the NF resistor, R51 is controlled, and the gain of the main
amplifier stage is lowered when TROS is ON, thus the voltage drift
(transient voltage) of the main amplifier at turning the power ON fig. 2
does not appear on the speaker terminals for very short period of
time. In other words, at the instant that the power is turned ON,
the voltage at the point A rises up to +13V, then the voltage de»
creases by means of the time constant of C40 and R88 as shown in
Fig. 2. At this time, the diode D11 is inversely biased, consequently,
the potential voltage of the point B is 0V as Fig. 3. Because of thls,
TROS turns to the cutoff, thus the NF resistor, R51 acquires such a
state as its resistance value becomes equivalently very large, which
deCreases the gain of the power amplifier. When the charge of the
C40 is completed, the voltage of the point B (see Fig. 3) becomes
negative, as a result, the diode DH is biased. Therefore, TROS is
turned 0N and the circuit of this equipment is normally operated
approximately 2 seconds after the power is turned ON to prevent
the pop noise which flows to loudspeakers.

+13V

e -2V

Time-> i

VOLTAGE»
o

'r->From this point the set begins
9 2 seconds ->i working normally

Power 0N
Voltage variation during a certain period
of time at ®

VOLTAGE+
o

Fig. 1 Fig. 3 Voltage variation at
Rs: _
Amw- to speaker terminals
IC01
021
R51