Technics RS-M228X - Page 18

a .
O13 D13, 14
D11, 12
7. 2SA999(E,F)
B+
10.57V
182473777
or
2SB641(R,S)
182473177
[MA161] [2SB641] [MA161)
Q14—16
D39, 40 D15, 16
2SC945(P.K) 452473177: 1$2473T77 \c4, 5
or 280636(R,S) ‘aver TMAtBt] [M5281]
[2SC945-Qj
1O57y
isan es R101
Vee disctHy 1 58K _ig 29y
1 {-10.30v)
DECODE {H)
1
ENCODE (Hi
1
dbx Block
ING our
54
room -- 5
----4
M.P.X1
0-9
[= 3] Pa
7P
(45 vO
R51 R53
150K ARS
7 +4)
6 23k
| c= |:
|
a3 i
PSCC 0.R o0lv g.0ay 5 tay 12K
: ! Legh sgsh | [MA161]
$2-4 Lt AW. a D yr +
See = = p28 RUS 4.7K \ é)
DdoO fF 182473LF saat] O18 ok tose
ROH [MA161] 838)
Qi
2SD965(Q,R)
[2SD965)]
Qs5—8
2SK104H
[2sk104] | 036,
4
Q10 852
2SC965(Q,R) 150K
[2SC965Q]
Qi9
2SA999(E,F)
or 2SB641(R,S)
[2SB641]
100k
~O2v
MUTING ON
0,68V
in
p38
[fs
ROS
TOK
37100
192473177
+10.5V
-10.5V
J
LCH OUT
GND to FL METER
RCH OUT SECTION
REC MUTE
AC3V
AC3V
Ars nA
~O-
T400mA
ropean areas IN * For Asia, Latin America, Middle East and Africa areas.
182473177 80
{2SD965]
[MA161]
1500P’
a
p29
AW
Tats RD8R2EB2LF
Pagel $2-7 20 ISVDRD82EB]
|. p19 Si-i4 182473177 | 20 7
21, 22 DOOOO ais7 330 [MA161] oa
182473177 @® @
mas ar
p19 cio denis 1536V
192473177 var 0K ee
[MA161]
(22V Q24 1K
Q23, 24 (0.26)
2SC945(P,K) KB
or 2SD636(R,S)
J [2SC945-Q] Cy)
= Oi | ay
7 Bi ae
4 RISB Ar2
—— ar
p45 D25, 26 OD @
182473
182473177
D27
aS
AGeaE
5
Yr
rae
.
[MA161} IMA161] 1SR35200LF H A
: d b—O—— « 1SM112]} °F 2SB641(R,S) b+ 400mA
SO
(
ii
maleic.
at
is
aS:
-
:
o—o
Dj
rower
suppty
*
For
all
Eu
a
89
26
a27
1¢7
SECTION
ited
Ki
(cro2)
(FF/REW)
(MUTING)
2801847(Q,R)
2SA886(Q,R)
[452301]
(M)
except
United
Kingdom
[2818470] [2SA886Q] MOTOR
(axuo297)
EQUIVALENT CIRCUIT
| t
AACIN
[A] * For Australia.
NOTES:
¢ $1-1—S1-14...... Record/playback select switch (shown in playback
position).
° $2-1—S2-8 ...... NR select switch (shown in DOLBY IN position).
(@®...Dolby IN, @)...Dolby OUT, @)...dbx Tape,
@...dbx Disc).
© $3-1—S3-4 ...... Input select switch (shown in LINE position).
e $4... ..Rec Mute ON/OFF switch (shown in OFF position).
¢ S5.. ..Power ON/OFF switch (shown in ON position).
¢ $6,S7 ... ..Auto tape select switch.
[= ya
Tomaitane | on | on
[co.tene | on | OFF
[wasps | oFF | oFF |
© SB eee ieietge dee Fast wind ON/OFF switch (shown in ON position).
.-Play muting ON/OFF switch (shown in ON position).
° $10 .. [BIN]: AC power voltage select switch.
» For all European areas except United Kingdom,
Asia, Latin America, Middie East and Africa areas.
eVR1,2. .Playback gain adjustment VR.
e VR3,4. .Input level controls.
e VR5,6. -Recording gain adjustment VR.
© VR7,8 . -Output level controls.
e VR9,10_ ... -Bias current adjustment VR.
¢ Connection points (a), (a’)...For playback frequency response adjustment
points.
* Connection points (b), (c) ...For erase current adjustment points.
Resistance are in ohms (&), 1/4 watt unless specified otherwise.
K = 1,0002, M = 1,000K.
Capacity are in microfarads (uF) unless specified otherwise.
P = Pico-farads.
The mark (¥) shows test point. e.g. V=Test point 1.
. indicates the flow of the playback signal (dbx out).
o( ) indicates the flow of the playback signal (dbx tape).
a | indicates the flow of the recording signal (dbx out).
(a ) indicates the flow of the recording signal (dbx tape).
e
Important safety notice
Components identified by A mark have special characteristics important
for safety. When replacing any of these components, use only
manufacturer’s specified parts.
¢ All voltage values shown in circuitry are under no signal condition.
Uniess otherwise specified, voltage measurement conditions are that tape
travels is at REC, tape mode at METAL, and NR switch at OFF.
( y,) Misageteeds Voltage at playback mode.
DOLBY IN .... Voltage value at IN (NR select switch) mode.
DISC .Voltage value at DISC (NR select switch) mode.
FF/REW ... -Voltage value at FF/REW mode.
MUTINGON ...... Voltage value at muting ON mode.
¢ Described in the schematic diagram are two types of numbers; the supply
parts number and production parts number for transistors and diodes.
One type of number is used for supply parts number and production parts
number when they are idential.
eg. Q1
2SB745(TMG, UMG)<—Production parts number
[2SB745T] «Supply parts number
D1
QVID1S2473T «—— Production parts number
jaaael + Supply parts number
¢ The supply parts number is described alone in the replacement parts list.
¢ This schematic diagram may be modified at any time
with the development of new technology.
* Output level control --- MAX.
SPECIFICATIONS — «* Input level controls --- MAX.
Playback S/N ratio Greater than 45 dB
* Test tape --- QZZCFM (without NAB filter)
Overall distortion Less than 3%
* Test tape
«++ QZZCRA for Normal
vo azzCRK forgroas Lessig .0 7.
-- QZZCRZ for Metal (CrOz, Metal)
(Normal)
Overall S/N ratio
* Test tape --- QZZCRA
Greater than 43 dB