Sony ta 3200 f service manual

Page 1

Dynamic power output:
llHFl

Continuous RMS
power output:
(rated output)
[LESS than 01 % THD]

Power bandwidth:
(IHF)

Harmonic distortion:
(20 Hz-ZO kHz)

IM distortion:

Freque ncv response:

SlN ratio:

Residual noise:

STEREll

SPECIFICATIONS

320 watts (8 ohms)
500 watts (4 ohms)

At I kHz

140/140 watts (8 ohms)

200/200 Watts (4 Ohms)

Per channel oueratlng

110 +110 watts (8 ohms)

130 +130 Watts [4 ohms)

80th channels driven Simultaneously
At 20 Hz-ZO kHz

100 t 100 watts/8 ohms

Both channels driven simultaneously

5 H2735 kHz

Less than 0.1 "/0 at rated output
Less than 0.05 % at 1 watt output

Less than 0.1 % at rated output
Less than 0.03 % at 1 watt output

4

5 Hz--200 kHz - 9 dB

(at 1 watt output, NORMAL/TEST
switch set at TEST)

NORMAL setting cuts low lreqtiencres
below 30 Hz 6 (JD/octave,

110 dB, short-CIrLUItnd

Less than 0.003p watt/8 ohms

E Model = General Export Model

Inputs:

Outputs:

Power requirements:

Power consumption:

Ac outlets:

Dimensions:

Net weight:

Shipping weight:

US Model

(Serial No. 810,001 and later)

E Model

(Serial No. 510, 001 and later)

Canadian Model

(SeriaINo. 710,001 and later}

POWER AMPLIFIER

Sensitivity 1.4 volts (for rated output)

Impedance: 75 k ohms

Two pairs of inputs equipped WIth
level controls.

Accents 4-16 ohm Speakers.
Equipped with two pairs of speaker
outputs:

120 volts ac (USA and Canada Model)
100,120, 220 or 240 volts ac
(General Export Model)

280 watts (USA Model)
610 watts (IEC standards)
600 VA (Canada Model)

Switched 1,Unswitched 1
Total 300 watts

400 (w) x 149 th) x323 (d) mm
153/4 (w) x 57/301 123/4 (d) inches

140 kg (30 lb 10 ozl
1647 kg [36 lb 14 all

SONY

SERVICE MANUAL

Page 2

SECTION 1
TECHNICAL DESCRIPTION

1-1. CIRCUIT DESCRIPTION DIGEST

The following describes the newly adopted cir-
cuit that might help you in repair work, Refer to the
schematic diagram on page 1 l.

(1) Low Filter Switch $2

C101 and R102 form a low-cut filter 6 dB/oct
below 30 Hz for eliminating extremely low
frequencies when the LOW FILTER swrtch is
set to NORMAL.

(2) Preamplifier (0101, 0102, 0103, 0104)

This is a modified paraphase amplifier but output
signal is extracted from the emitter circuit of
0102. Note that 0101 and 0102 are in a
Darlington configuration and 0104 acts as a
constant current source. These circuits have
Various advantages in a direct-coupling system
One is high stability despite temperature varia-
tion and another is high input impedance with-
out reducing the amplifier gain. The ac output
appears across R108 in the emitter circuit of
0102 while the decoupling circuit is formed by
the emitterehase resistance of 0103, C104 and
R109. C104 and R109 form a frequency»
selective ac bypass to reduce amplifier gain at
very low frequencies. 0104 keeps the dc current
flow constant in 0101, 0102 and 0103, thus
increasing the dc stability.

Noise Suppressor

[)101 connected to 0104 reduces the popping
norse due to unbalanced current flow in the
following stages when the power switch is turned
off.

Dc Balance

R105 provides a stabilized bias voltage for

(3)

(4)

transrstor 0101 to set the output terminal volt-
age at zero dc. This also enables TA-3200F to
provide same but opposite poled output to the
load.

Pre-Driver 0106

Though this stage is a conventional flat ampli-
fier it determines the output voltage swings
because the following stages are basically emit-
ter-followers. The ac load resistor for this stage
is R1 12 (4.7 k).

Dc Bias Adj.

0105 is biased into conduction and operates
as a small resrstance providing the necessary
forward bias on the two c caded emitter fol-
lowers. R116 controls the base bias of 0105,
determining its emitter~collcctor impedance and
thereby controls the dc bias voltage for the
following circuit, D102 provides thermal comv
pensation for the following complementary and
power transistor circu1ts. D102 is attached to
the power transistor heat sink to detect temper-
ature increase in the power transistors.

Protection Circuit

Two kinds of protection circuits are used in
this power amplifier. One is a power transistor
protection and the other is a speaker protection
circuits.

Pa wer Transistor Protection

Referring to Fig. 1-1, the protection circuit ope-
rates as follows: (Since the protection circuit is
identical for positive-and negative-half cycles,
only the positive half cycle operation is de-
scribed.) During normal operation, 0107 and
0114 are cut off (the load impedance is 2 ohms
or more) and have no effect upon power tran-

0110

D104

0112

0108
0103

R135

Fig. 7-7. Simplifiedpower transistor protection circuit