Sony STR-SE381 User manual

STR-SE381
US Model SERVICE MANUAL
FM STEREO/FM-AM RECEIVER
MICROFILM
ManufacturedunderlicensefromDolbyLaboratories
Licensing Corporation.
“Dolby” “Pro Logic” and the double-D symbol aare
trademarks of Dolby Laboratories Licensing
Corporation. SPECIFICATIONS
— Continued on next page —
Audio power specifications
POWER OUTPUT ANDTOTAL HARMONIC DISTORTION
With 8-ohm load, both channels driven, from 40 - 20,000 Hz,
rated 60 watts per channel minimum RMS power, with no more
than 0.5% total harmonic distortion from 250 milliwatts to
rated output.
Amplifier section
Stereo mode (8 ohms at 40 Hz - 20 kHz less than 0.5% total
harmonic distortion)
60 W + 60W
Surround mode (8 ohms at 1 kHz, THD 0.5%)
Front: 60 W/ch
Center: (Pro Logic Mode)
60 W
Rear: 60 W/ch
Frequency response PHONO: RIAA
equalization curve ±0.5 dB
TV/DBS, CD, TAPE/MD, VIDEO INPUT
10 Hz - 50 kHz ±1 dB
Inputs
Sensitivity Impedance S/N (weighting network,
input level)
PHONO
(MM) 2.5 mV 50 Kilohms 72 dB*
(A, 2.5 mV)
CD 400 mV
TAPE/MD, 250 mV
TV/DBS, 50 Kilohms 82 dB*
VIDEO (A, 150 mV)
*78 IHF
Outputs TAPE/MD REC OUT:
Voltage: 150 mV,
Impedance: 10 kilohms
VIDEO AUDIO OUT:
Voltage: 150 mV,
Impedance: 10 kilohms
PHONES:
Accepts low and high impedance headphones
Muting Full mute
BASS BOOST +10 dB at 70 Hz
TONE ±8 dB at 100 Hz and 10 kHz
FM tuner section
Tuning range 87.5 - 108.0 MHz
Antenna terminals 75 ohms, unbalanced
300 ohms, balanced
Sensitivity Mono: 18.3 dBf, 4.5 µV
Stereo: 38.3 dBf, 45 µV
Usable sensitivity 11.2 dBf, 2 µV (IHF)
S/N Mono: 76 dB
Stereo: 70 dB
Harmonic distortion at 1 kHz Mono: 0.3%
Stereo: 0.59%
Separation 45 dB at 1 kHz +0.5
Frequency response 30 Hz - 15 kHz –2 dB
Selectivity 60 dB at 400 kHz
AM tuner section
Tuning range 531 - 1710 kHz
Antenna Loop antenna
Usable sensitivity 50 dB/m (at 1,000 kHz)
S/N 54 dB (at 50 mV/m)
Harmonic distortion 0.5% (50 mV/m, 400 kHz)
Selectivity At 10 kHz: 40 dB

STR-SE381
— 9 — — 10 —
3-3. SCHEMATIC DIAGRAM — DISPLAY SECTION — • See page 6 for Waveforms. • See page 25 for IC Pin Functions. • See page 27 for IC Block Diagrams.

STR-SE381
— 13 — — 14 —
3-5. SCHEMATIC DIAGRAM —VOLUME SECTION — • See page 7 for KEY Board Wiring Board.

STR-SE381
— 17 — — 18 —
3-7. SCHEMATIC DIAGRAM — MAIN (1/3) SECTION — • See page 27 for IC Block Diagrams.

STR-SE381
— 21 — — 22 —
3-9. SCHEMATIC DIAGRAM — MAIN (2/3), POWER SECTION — • See page 27 for IC Block Diagrams.

STR-SE381
— 23 — — 24 —
3-10. SCHEMATIC DIAGRAM — MAIN (3/3), SP SW SECTION — • See page 12 for SW Board Wiring Board. • See page 27 for IC Block Diagrams.

— 27 —
3-12. IC BLOCK DIAGRAMS
IC300 LV1016
IC301 LA2786
15 6
+
–
+
20 19 18 17 16 15 14 13
21
22
2324
2 3 4789 10 12
11
+
DEC
IN-FILTER
(40kHz)
VDD
ADM-CONT SRAM
ADM
OUT-FILTER
(7k/5k)
B-NR
DC-OUT
VOL/MUTE
S-TRIM
INV-PHASE
R+DELAY
L+DELAY
A
B
A
B
A
B
A
B
A
B
A
B
A
B
L–R
L+R
(–6dB)
A
B
A.GND L-OUT
R-OUT
VREF S-OUT
DELAY-OUT
S-IN
R-IN
L-IN
VCC
NR-DET
ENABLE
DATA
CLK
D.GND
DC-CUT VDD OSC OSC
NR-IREF
DC-CUT
1
2
3
4
5
6
7
8
9
15
10
11
12
–+
13
14
16
21
18
19
25
17
24
22
23
20
34
32
33
29
30
35
28
31
27
26
36
40
39
38
37
41
42
NOISE
FILTER NOISE
CH
BALANCE
CONTROL
VR
CONTROL
LPF
V REF
VR
VR
NOISE
GENERATOR
VCA
VCA
VCAVCA
VCAVCA VCAVCA
LPF
LPF
RECT RECT RECT RECT
P. S.
P. S.
CMODE
MUTE
DIVIDER OSC
CONTROL
CTRIM
LOG
DIFF LOG
DIFF
DUAL T
CONTROL
L-IN
R-IN
VSS
CLK DATA VCC
L-OUT R-OUT
S-OUT C-OUT
ENABLE
OSC1 CMODE-CAP. C-TRIM DC CUT R-BPF1 R-BPF2 R-BPF3 DC CUT DC CUT L-R RECT L+R RECT VCS-TH VCS-1 VCS-2
BPF1 BPF2
VREF
S-CH DC OUT C-CH DC OUT
L-CH DC OUT
R-CH DC OUT
VREF
L-BPF1 L-BPF2 L-BPF3
DC CUT DC CUT
R RECT
L RECT
VLR-TH
VLR-1 VLR-2

— 28 —
IC401 LC7822
IC701 µPC2581
IC202 BA6208
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
CONTROL
LATCH
SHIFT RESISTOR
LEVEL SHIFT
CL
DI
CE
VEE
OUT
IN
OUT
IN
OUT
IN
VSS
S
RESET
VDD
OUT
IN
IN
OUT
IN
OUT
IN
235
46798
1
MUTE
+ VOUT1 – VOUT1
COMP1
MF1
IN1
GND
IN2
NF2
COMP2
– VOUT2 + VOUT2
VCC1 VCC2
VEE
PROTECTOR
BIAS CIRCUIT
REG DRIVE PRE
DRIVE
11
10 12 13 1514
DRIVE
PRE
DRIVE
1 2 3 4 5 6 7 89
NC
OUTPUT 2
Vcc
GND
NC
INPUT 2
INPUT 1
NC
MOTOR
DRIVE
MOTOR
DRIVE
REG
SWITCH
SWITCH
OUTPUT1