LENCO LA1200 User manual

Lenco
AF
3302
Service Manual
MODELS
LA1200 STEREO POWER AMPLIFIER

LA1200 STEREO POWER AMPUFIER
Amplifier Section
Continuous average power output
(ooth channel driven) :
into 8 Ohms (from 20HzZ to 20KHZ).................. 125W
into 8 Ohms (from 1KHZ) ...... 0... cee ee eee es 150W
into 4 Ohms (from 1KHZ) ......... 0... cece cee eee ees 200W
Total Harmonic Distortion
into 8 Ohms (from 20HZ to 20KHZ).............. evan 01%
into 8 Ohms (from 1kHZ)......... 0.0... ccc cee eee 0.03%
into 4 Ohms (from 1kKH2).......... 0.0.0 ccc cee eee 0.05%
FRONT PANEL FEATURES
oo0a O.
did HY
NASA ITZ
ILM. Distortion. ...... 0.0... 0. cece eee eee ide wean 0.03%
Signal to Noise Ratio (IHF “A” Network) ........... 120dB
Input (Sensitivity/Impedance) ..................0. 1V/47kQ
Frequency Response .
202 10 TDOK AZ aas daned cin cee eee ene ee eete es = OOo
DaMpINO FaCtOl cic 45 ecu sb eeee em sah een ena ids 1. 45
Power “ON” Muting Time............ 0. cece eee o—7 sec
Miscellaneous | | | .
Power requirements ........... saat Me cuban AC220V, 50 Hz
Power Consumption..............0c0ccee 435 W, 530VA
DIMENSION 2.5.3.5 toeeeeews 420(W) x 132(H) x 350(A)mm
001003
Wd YH
DANS HL
a 2 8 4 8
1. POWER SWITCH
Depress switch to ON position to supply power to the am-
plifier.
2. OUTPUT LEVEL METER
The output power level meters give a visual indication of
audio power being delivered to each speaker.
'3 6PROTECTION CIRCUIT OPERATION INDIC-
ATOR LAMP
A red LED indicates when the protection circuit is ac-
tivated and a green LED indicates when the protection
Circuit is off.
The protection circuit activates fora5—7 second period when
the unit is powered on and whenever the unit overheats
beyond a specific temperature.
4. SPEAKER “A” SELECTOR SWITCH
Depress button to listen to the speaker Systems con-
nected to the speaker A terminals.
(ON) — Depressed position; Sound is heard from speaker
systems.
(OFF) — Released position; NO sound is heard from
speaker systems.
5. SPEAKER “B” SELECTOR SWITCH
Depress button to listen to the speaker systems con-
nected to the speaker B terminals.
(ON) — Depressed position; Sound is heard from speaker
systems.
(OFF) — Released position; NO sound is heard from
speaker systems.
Note :When both buttons are depressed both speaker
pairs A and B are selected.

BLOCK DIAGRAM
INPUT
LEFT
INPUT
RIGHT
LCH
POWER
AMP
|
CED
GEE
OD
EEE
ED
FROM
LEFT
POWER
LEVEL
METER
POWER
SUPPLY
—
;
g
ee ee
ee
Te
ER
ge
ee
ey
ge
ea
ae
eye
na
Fe
OE
ae
ete
er
ay
pe
Rage
a
WE
LE
gh
ee
eae
Ln
ea
Gene
Ghee
Tae
Mem
y
eT
Oa
Te
eg
eee
tees
oe
POWER
LEVEL
METER
i

NOTES:
¢
Parts
without
part
number
cannot
be
supplied.
°
The
/\
mark
found
on
some
component
parts
in-
|
dicates
the
importance
of
the
safety
factor
of
the
part.
.
:
|
Therefore,
when
replacing,
be
sure
to
parts
of
identical
designation.
.
|
e
For
your
Parts
Stock
Control,
the
fast
moving
items
are
indicated
with
the
marks
**and**
**
GENERALLY
MOVES
FASTER
THAN**
This
classification
shall
be
adjusted
by
each
distributor
because
it
depends
on
model
number,
temperature,
humidity, etc.”
Mark
No.
Part
No.
Description
Mark
No.
Part
No.
Description
1
NNB-123-0
Front
Panel
27
VBZ30PO80FMC
Screw
2
NNA-284-C
Panel
Stay
28
BBZ30PO80FMC
=
=
Screw
3.
NND-038-A
Bottom
Plate
29
VBZ30PO080FMC
Screw
4
NNA-283-A
Side
Frame
30
BBZ30PO080FMC
Screw
5
NNA-343-0
Rear
chassis
31
VMZ30PO80FMC
Screw
6
NNE-O051-A
Bonnet
Case
32
BBZ30PO80FMC
Screw
7
NNW-766-A
Reflector
33
BBZ30PO60FMC
Screw
J\
8
NTT-147-0
Transformer
34.
\VBZ30P100FMC
Screw
9
NKE-004-0
Push
Terminal
35
VBZ40PO80FMC
Screw
10
NNW-775-0
‘Function
Knob
‘B’
36
BBZ30PO80FZK
Screw
11.
NNWN-825-A
Window
38
BBZ30P080FZK
Screw
12
NNW-959-A
Sub
Escutcheon
39
VBZ30PO80FZK
Screw
13.
NNM-045-0
LED
Sheet
40
FBT40PO80FZK
Screw
14.
NNW-711-0
Power
Knob
41
BBZ30PO80FZK
Screw
15
NNM-062-0
Sub
Plate
42
BBZ30P080FZK
Screw
_
16
NEL-003-B
Pilot
Lamp
Ass’y
43
NBM-007-0
Plastic
Rivet
Zi\
17
NSA-005-0
Push
SIW
44
BBZ30PO80FMC.
Screw
(ESB997V8)
45
BBZ30PO080FMC
Screw
*18
NEK-102-0
Fuse
(2A)
46
VMZ30PO80FMC
Screw
Z\
19
NNP-064-0
AC
Outlet
47
NNM-062-0
Sub
Plite
(S-16521#01)
48
NWH-017-0
Main
PC.P
Ass’y
20
NWT-024-0
2P
Phone
Jack
49
NNW-906-0
Joint
21
NKR-008-0
Fuse
Holder
50
BBZ30PO80FMC
Screw
*22
NEK-105-0
Fuse
(8A)
51
3
NNF-151-0
Heat
Sink
Support
23
406000009000
Strain
Relief
Bushing
52
NNH-065-0
Heat
Sink
Zi,
24
NDG0230
Power
Cord
2
NAW-023-A
Meter
26
NNV-006-0
Foot
eee F oa a ‘ ee) f eae Z
Fs er ae ae a3 PRES ee ee Ee are . 7
sic i st a ch ek
CT ey eT eT Ee SET Te ee ye eee ee ee eee Se SEE ON Ne eee DEE AEE a Re
OE ET A LT Mele a ee ae
Fi a ee Ee ae al a alge
ee ee EE Ee NL ee EE TRS ROT E T EE SRR, PERCE ey NOP TN: REE PS OR ae

Fig
1.
ae
4.
POWER
METER
ADJUSTMENT
WITH
POWER
“OFF”
Remove
front
panel
and
adjust
the
meter
needle
to
“Q”
on
the
scale
(Fig.
1)
‘
.
POWER
METER
ADJUSTMENT
WITH
POWER
“ON”
Tum
power
on,
feed
a
1kHz,
1V
RMS
signal
from
a
signal
generator
to
the
L
channel
input
jack
of
the
PA-1200B
With
the
speaker
or
8
ohm
dummy
look
removed,
adjust
VRI102
till
the
meter
needle
points
to
“low”
on
the
scale.
SS
3.
Set
R
channel
meter
by
adjusting
VR101
in
the
same
manner
and
signal
fed
into
the
R
channel
in
put jack.

NOTES:
When
ordering
resistors,
first
convert
resistance
values
into
code
form
as
shown
in
the
following
examples.
Ex.
1.
When
there
are
2
effective
digits
(any
digit
apart
from
0),
such
as
560
ohm
and
47k
ohm
(tolerance
is
shown
by
J=5%,
and
K=
10%).
560 9=56x10' — 561............ RDV4PS 561J
47K N= 47 x 10°-- 473... 2.2.00... RDVPS 473J
0.50 — ORS......... cece eee eee RN2H ORS5K
AO O10 enetet cous oea sas haanwens RS1P 010K
Ex. 2. When there are 3 effective digits (such as in
high precision metal film resistors).
5.62k0 562 x 10' 5621............. RN %SR5621F
The /A\ mark found on some component parts indi-
ates the importance of the safety factor of the part
‘therefore, when replacing, be sure to use parts of iden-
tical designation.
For your Parts Stock Control, the fast moving items
are indicated with the marks * *and**
**GENERALLY MOVES FASTER THAN**
This classification shall be adjusted by each distributor
because it depends on model number, temperature,
humidity, etc.
Miscellaneous Parts List
P.C. BOARD ASSEMBLIES
Mark Symbol & Description Part No.
PCB B’D NNP-294-A
Main PCB Ass’y NWM-106-0
LED PCB Ass’y NWS-057-0
Jack PCB Ass’y NWS-058-0
OTHERS
Mark Symbol & Description Part No.
Th. Ceramic Capacitor (0.01 400V) NCG-002-0
AX Power transformer NTT-147-0
AC Socket (8P) (AC Outlets) NKP-064-0
Z\ Fuse NEK-102.0
/\, Fuse NEK-105-0
** AC Power Cord NDG-023-0
/\ Switch (Power NSA-005-0
SEMICONDUCTORS
Mark Symbol & Description Part No.
** 10101 LR STK4048XI1
** — 1€102 TA7317P
** 10103 TA7318P
* — Q101LR KTC2240Y or
GR
* — Q102 KTA970Y or
GR
* — Q103, Q104 KTC1815Y or
GR
Mark Symbol & Description
* D106
* D101 U/R,D102,-D107, D108
* D109 UR
* D103
RELAY
MARK Symbol & Description
RLY101
COILS
Mark Symbol & Description
L101 LR (AF COIL)
SWITCH
Mark Symbol & Description
SW103, SW104 (Push Switch)
OTHERS
Mark Symbol & Description
2P Pin Jack
Part No.
BR252
IN4002
1S2473
IN9S65A or
DZ15E
Part No.
NSR-016-0
Part No.
ATH-054-0
Part No.
NSA-004-0
Part No.
NKB-002-2
Rasta ti st otatte aa
;
‘
a
4
e
#
A
5
‘
t
3
|
4
4

RESISTORS
Mark Symbol & Description
R109 L/R, R110, WR, R111 LR,
R112 UR
R139, R140
R116L/R
R118U/R
R101, LR, R103 L/R, R123
R104L/R
R125, R132, R146, R149
R120
R117U/R
R107 L/R, R147, R148, R151,
R153
R119
R124, R127, R105 L/R
R129
R115 L/R, R121, R135, R136,
R145
R152, R102 L/R
R130
R122, R131
R126
R128
R143, R144, R150
CAPACITORS
Mark Symbol & Description
C122
C110 WR, C111 UR, C115L
C116L, C137 L/R
C102 UR, C136
C123, C124, C125, C126,
C138, C139
C118
Part No.
NCN-010-0
RDV%4 PM150J
RD% PM331J
RD%4PM821J
RD%4PM102J
RD%PM561J
RD%PM222J
RD%4PM512J
‘RD % PM562J
RD%4PM103J
RD% PM123J
RD%4 PM203J
RD% PM333J
RD%4PM473J
RD 1% PM563J
RD PM104J
RD 4 PM224J
RD%4PM332J
RD%4PM101J
CEAR47M50L
CEA010MS0L
CEA4R7M50L
CEA100M50L
CEA220M25L
Mark Symbol & Description
C120
C119
C104 UR
C108 UR, C109 LR, C106R,
C107R
C106L, C107L
C105 UR
C103 WR, C112 LR, C114 UR
C101U/R
C113 UR
C127, C128
C121
C117 UR
RESISTORS
Mark Symbol & Description
VR101, VR102
R113 UR, R114 UR
Z\ R106, UR, R108 LR
Z\, R133, R134
/\, R137, R138, R141, R142
CAPACITORS
Mark Symbol & Description
C130, C131, C132, C133
C134, C135 (10,000/80WV)
Part No.
CEA330M25L
CEA470M25L
CEA101M25L.
CEA221M50L
CEA221M35L
CCDSL100J50
CCDSL101J50
CCDSL471J50
CKDYB102J50
CQMA102J50
CQMA103J50
CQMA473J50
Part No.
NCP-034-0
RSIL100J
RSIL101J
RSIL3832J
RSIL682J
Part No.
NCG-001-1
NCH-010-0

‘
{
'
8
g
i
i
4
&
|
.
;
i
{
:
4
:
}
i
§
Mark
No.
Part
No.
Description
NRB-023-0
Operating
Instruction
NEC-009-0
Poly
Sheet
Power Amp Set
NHA-256-0
Side
Pad
(R.
L)
NHG-273-0
Packing
Case
1
2
3
4
5

SCHEMATIC DIAGRAM
PCB NNP-294-A
MAIN B'd
NWM
—
106-0
_
| RICBL 100(Iw)
,
| IC 101L
4048 X
|
STK
4048XI
PL:
PR
=
PTH487
AO!
B0222TS
ne
GCBK(IMX2
|
POSISTOR
(
MURATA)
a
Z ¢c128
|
+
10/50
| POWER LEVEL METER
LEFT RIGHT
@ @
Poa / ro /NX
| oe |0
| lise ne4
180 so
rn mn ae eee
R42
8. Si \WIX2 LEFT
ieee CO Oe: es SPEAKER A
a SPEAKER Sw
swios re}
ae Cae
— es
—)
|
O
RIGHT
©) O LEFT
KLG 20BE
A SPEAKER 8B
220/80
X
2
Dios
.
f
Be
SPEAKER
Sw
G
CIOBR
§=CIOOR
«nee
tootw)
_
.
iN
400R
pia
~
ee
Bioik
QIOIR
+
Y/GR
|
|
7
PCe8
BD
'
@wS-O5?-0
cicer
O RWOIR K 47/50
ee
Brose
RIOR
470P a2r/(sw \
|
R153
paar CI7R 10K
0.47 (mM)
mR O.27(SW)
;
R1I4ER
[\
a
10 (re)
AC INPUT
RHU2R
O27
(Sw)
220V
/
SOHz
|
t
| RIO6GR
CIOGR
ciosR OP cio7e |* 220750 X2
:
]
t RIOSR | |
CiO4R
100/28
20K
1
RIOSR 3 |
$60 :
[on GeeeeeE © GEEewe=e== 0: GES @ CeeeED @ CEES eTe 6» CEE & EES GS GETS GP GUESS CD SS OO CS GS em Cues GS Gare G> GEESE as Gece GD

EXPLODED
VIEW

TOP
VIEW
OF
P.C.
BOARDS
POINT-TO-POINT
WIRING
DIAGRAM
INPUT JACK ASS’Y
POWER TRANS
SW |0l
YELLOW
i
F1Ol
MAIN.
UNIT
ASS’Y
|
oe
C10)
|
Ad
|
=
|
|
O001/400WV
|
|
7
BLUE
|
BLUE
|
a
i
[|
|
|
|
AC
OUTLET
=
AC
INPUT
:
el
es
220V
/SOHz
SPEAKER
re
:
TERMINAL
SPEAKER 5
TERMINAL
RNAS te
POWER
LEVEL
METER
LEFT
3
POWER
LEVEL
METER
RIGHT