Technics RS-M226 User manual

ORDER NO. ARD82060161C8-11
Service
Manual
Cassette Deck
Soft-Touch
Cassette
RS-M226
Deck
with
Dolby
B-C
NR
(ee
Sied
Silver
Face
This is the Service Manual for the }
| following areas.
a) oe For all European areas
| except United Kingdom.
|B) eee For United Kingdom. |
DC [porev 8-c nm
Please use this service manual for the RS-M226. (Discard the
service manual prepared for the order No. ARD82050142C8-11.)
RS-M24 MECHANISM SERIES
Specifications
Track system: 4-track 2-channel stereo recording and playback Inputs: MIC; sensitivity 0.25 mV, applicable microphone
r. a ety impedance 4002—10kQ—
gee SReees Ones LINE; sensitivity 60 mV, input impedance more
Wow and flutter: 0.048% (WRMS), +0.14% (DIN) er . ce ae eee
: ut lev m impedan
Frequency response: Metal tape; 20—18,000Hz ae less ia 23 ko Dia ee aos
30— 17,000 Hz (DIN) HEADPHONES; output level 80mV (82)
CrOz tape; 20—18,000Hz applicable headphone impedance 8 2—600 Q
30— 16,000 Hz (DIN) Bias frequency : 80 kHz
Normal tape; 20 17,000Hz Motor: Electrical DC governor motor
30 — 15,000Hz (DIN) Heads: 2-head system
1 MX head for rec/playback
Signal-to-noise ratio: Dolby C NR in; 75dB (CCIR) 1 double-gap ferrite head for erasure
Dolby B NR in; 67 dB (CCIR) Power requirements: [DB] --- AC 220 V, 50-60 Hz
NR out: 57dB (for all European areas except United Kingdom.)
(signal level=max. input level A weighted, CrO eee
gnal level =max. input level A weighted, CrO2 ;
(only for United Kingdom.)
type tape) Power consumption: 12W
Fast forward and Dimensions: 43.0 cm(W) x 10.9cm(H) X 23.3 cm(D)
rewind time: Approx. 90 seconds with C-60 cassette tape Weight: 4 Okg
Specifications are subject to change without notice.
* ‘Dolby’ and the double-D symbol are trademarks of Dolby Laboratories.
Technics
Matsushita
Electric
Trading
Co.,
Ltd.
P.O.
Box
288,
Central
Osaka
Japan

RS-M226
CONTENTS
ITEM PAGE ITEM PAGE
LOCATION OF CONTROLS BLOCK DIAGRAM cercccrcereecerceeetecereeeeeeneaeeetenans 9
AND
COMPONENTS
-oeeccccceeeeteeteeteseeeeseeeeeees
2
SCHEMATIC
DIAGRAM
-rcccceeeereeccectcececeeeeeeeess
13
DISASSEMBLY INSTRUCTIONS 3 -+-trr-srsrse sere 2 CIRCUIT BOARDS AND
MEASURMENT AND WIRING CONNECTION DIAGRAM -+++++ee-++0+ 15
ADJUSTMENT
METHODS
---eeccceerreeeteteet
teres
3
MECHANICAL
PARTS
LOCATION
-orrrereeeceertee:
18
ELECTRICAL
PARTS
LOCATION
crveersrcteeeteete
8
CABINET
PARTS
LOCATION
-orerreecccterrreeteenteees
22
LOCATION OF CONTROLS AND COMPONENTS
7 Headphones Jack (phones) Tape Counter (tape counter)
Power Switch [power (push on)] Recording Indicator (rec)
Eject Button (eject) Input Select Button
{input select (Mlinee = mic)|
Cassette Holder FL (fluorescent level) Meter
|
XX ___| @
Input Level Controis
[input level(L -> R)]
Gar Selector
{tape select (NormaleCrOzeMetal)|
Fast Forward/Cue Button
(ff/cue (PP )])
Dolby Noise Reduction Select
Counter
Reset
Button
Switch
[Dolby
NR
(2
Be
=
@)]
{counter reset)
Rewind/
Review Button
[rew/rev
(
44
)]
Microphone
Jacks
[mic (lefteright)]
Dolby Noise Reduction Switch
(Dolby NR (2 oute™ in)}
en ene enn & 7— AC Power Voitage
Select Switch
= ae SE 5
|
Play
Button
Record
Button
—
fl
|
(play- 2(>)] iree-& (O)] (cae “P|
——- { eo 4-4
|
i
Stop Button Pause Button
[stop (m)] (pause (11)] L
Line Output Jacks [LINE OUT (LeR)]
—— Line Input Jacks [LINE IN (L@R)]
DISASSEMBLY INSTRUCTIONS
* The head azimuth
can be adjusted by removing
the cassette lid.
| Fig. 1
Power
supply
(D) circuit Flat
Record/
playback
connection
wire
iRecord/playback =p
‘connection ss \
iwire A
circuit (F
board
Fig. 5
—2—

RS-M226
Procedure To remove —— . ; Shown in fig. —— .
1 Case cover * 2 screws 1
+ 3 screws
(Slide in direction of arrow)
Bottom cover
+ Pull out the flat cable from
connector
Power supply circuit * 2 Screws
board * Cord clamper
+ Pull out the switch rod-C
+ 2 red screws
Front panel
FPR] WM] WWWWWw
FL.
meter
unit
+
Meter
cover
and
meter
filter
+
Pull
out
the
FL
meter
unit
+ 3 red screws
* Pull out the switch rod-E
+ Pull out the flat cable from
connector [4]
* Pull out the socket
+ As shown in fig. 3, push the claw in
the direction of arrow (®, {lift the
main circuit board in the direction
of arrow @.
+ Remove the record/playback
connection wire in the direction of
arrow @) while lifting the main circuit
board in the direction of arrow @ as
shown in fig. 3.
17 2-4>5->6 Main circuit board
+ Cassette lid
1324-57 Mechanism unit * 4 red screws
»* Pull out the counter reset lever
17 2-45-78 Cassette holder
Se gee” OSA A ATPRILOHY: So ° «ie
(TPO (TPO | geelrpatecny TRB /TP7\
\ a A \ !
IU J dein 14° | VRS vR6e * ay. veay:
a APIN J pea
N, ‘ * ye
swe ~
XN
Tape speed
adjustment VR \
/ TP6 \
K P
Fig. 1
NOTES: Keep good condition, set switches and controls in the following positions, unless otherwise specified
@ Make sure heads are clean e Tape selector. Normal position
@ Make sure capstan and pressure roller are clean @ Input selector: Line in
© Judgeable room temperature: 20 +5°C (68 + 9°F ) ®@ Input level controls: Maximum
® Dolby NR switch: OUT

RS-M226
ITEM MEASUREMENT & ADJUSTMENT
@
Head
position
(The
head
adjusting
plate
is
provided
to
adjust
the
tape
Screw
(A)
adjustment
touch
of
the
head
in
cue
or
review
mode)
Capstan
Condition 1 Press the playback button and pause button
* Playback and pause mode 2. Measure the space between the pressure roiler and the (B)
capstan
Head Adjusting Plate
Pressure Roller
Standard value: 0.5+0.3mm
Space (adjustabte)
If the measured value is not within the standard value, -” }
untighten screw (A), and slide the head adjusting plate ;
in the direction of arrow (B) for adjustment Fig. 2
@ Head azimuth L-ch/R-ch output balance adjustment LINE QUT
adjustment 1. Make connections as shown in fig. 3. merpeu/ paynael
Condition
+ Playback mode : _ os sill
: Playback the 8kHz signal from the test tape (QZZCFM) Playback mode VIVM Oscilloscope
Equipment
:
abe
;
;
i
Ve
2
Oaslotone
ene
(B)
in
fig.
4
for
maximum
output
L-ch
and
Fig.
3
* Test
tape
(azimuth)
When
the
output
levels
of
L-ch
and
R-ch
are
not
at
c
pees
Mint
~
Q2ZCFM
maximum
at
the
same
time,
readjust
as
follows
Turn
the
screw
shown
in
fig.
4
to
find
angles
A
and
C
(points
where
peak
output
levels
for
left
and
right
channels
are
obtained).
Then,
locate
the
angle
B
between
angles
A
Screw
(B)
Fig.
4
and
C,
i.e.,
a
point
where
L-ch
and
R-ch
output
levels
come
together
at
maximum.
(Refer
to
figs.
4
and
5.)
ee
Roh
peak
level
L-ch/R-ch phase adjustment
4 Make connections as shown in fig. 6.
5. Playback the 8kHz signal from the test tape (QZZCFM)
Adjust screw (B) shown in fig. 4 so that pointers of the two
VTVMs swing to maximum and a waveform as illustrated in
fig. 7 is obtained on the oscilloscope
Oscill
VIVM| illoscope
Playback {ine :
mode Qyt Vertical Horizontal Fig. 6
@
Tape
speed
Tape
speed
accuracy
Record/playback
head
Condition
1
Test
equipment
connection
1s
shown
in
fig.
8.
eae
*
Playback
mode
2.
Playback
test
tape
(QZZCWAT
3,000Hz2)
at
middle
section
eo]
and
supply
playback
signal
to
frequency
counter.
Test
tape
Payback
mode
Digital
electronic
counter
3
Measure
this
frequency
Fig.
8
4.
On
the
basis
of
3.000Hz.
determine
value
by
following
formula
LINE OUT
Equipment
* Digital electronic counter or
frequency counter
* Test tape --- QZZCWAT t -- 3.000
Tape speed accuracy = 3000 x 100(%) where. f -. measured value
f
| Standard value: +1.5%
Adjustment method
1 Playback the test tape (middle)
2 Adjust so that frequency becomes 3.000 Hz
3 Tape speed adjustment VR shown in fig. 1.
Tape speed fluctuation
Make measurements in same manner as above (beginning, middle and end of tape), and determine the
difference between maximum and minimum values and calculate as follows
: f:—fe
Tape speed fluctuation = 3 00. 100 (%) f: = maximum value, f» = minimum value
Standard value: Less than 1%
Note:
Please use non metal type screwdriver when you adjust tape speed accuracy on this unit.

® Playback frequency
response
Condition
+ Playback mode
* Tape selector
-- Normal position
Equipment
*VTVM
+ Test tape---
* Oscilloscope
QZZCFM
ony
fig. 3.
Test equipment connection is shown in
ITEM MEASUREMENT & ADJUSTMENT
Playback frequency response chart
RS-M226
@ Playback gain
Condition
* Playback mode
* Tape selector
-»Normal position
Equipment
*VTVM
* Test tape--:
* Oscilloscope
QZZCFM
@ Erase current
Condition
* Record mode
* Tape selector
-- Metal position
Equipment
«VTVM
* Oscilloscope
2.
Place
UNIT
into
playback
mode
aig
100
hee
7
+6d8
3. Playback the frequency response test rade Se - ee are $hc8
tape
(QZZCFM)
sae
m@annuiaeal
4
Measure
output
level
at
315Hz,125kHz
|
#8
:
2H
haa
8kHz, 4kHz,
1kHz,
250Hz,
125Hz
and
=
|7
288
ial
248
63Hz. and
compare
each
output
level
4
erie
q
foe
“To
408
with
the
standard
frequency
315
Hz.
at
eG
oon
|
eas
r
ai
This
*
rivets
LINE
OUT
200Hz
500
Hz
GkHz
10kHz
5. Make measurement for both channels ,
6 Make sure that the measured value is Fig. 9
within the range specified in the frequency response chart (shown in fig. 9).
1 Test equipment connection is shown in fig. 3.
2. Playback standard recording level portion on test tape (QZZCFM 315Hz), and using VTVM measure
the output level at LINE OUT
3. Make measurement for both channels
Standard value: 455mV+1dB [around 280 mV: at test points TP3 (L-CH) and
TP4 (R-CH)]
Adjustment
RQ
tf measured value is not within standard, adjust VR3 (L-CH), VR4 (R-CH) (See fig. 1 on page 3).
After adjustment. check “Playback frequency response’ again
Test equipment connection 1s shown in fig. 10.
Press the record and pause buttons
1
2
3. Set the tape selector to metal position
4
Read voltage on VT VM and calculate erase current by
following formula
Erase current (A) =
Voltage across both ends of R124
1 (Q)
Standard value: 155+15mA (Metal position)
5. If measured value is not within standard, adjust as follows
Adjustment
1. Open the point (A) and short the point (B) on the main circuit board in the wiring connection diagram
(See page 15).
2. Make measurement for erase current
3. Make sure that the measured value is within the erase current of 140 mA to 170mA
4. If it is beyond the value, carry out the following adjustments
* If the erase current is less than 140 mA, short the point (A)
* {f the erase current is more than 170 mA, open the points (A) and (B)
© Overall frequency
response
Condition
* Record/playback mode
* Tape selector
-- Normal position
--CrOQ. position
--Metal position
* Input level controls --- MAX
Equipment
*VTVM * AF oscillator
* ATT * Oscilloscope
* Resistor (60002)
* Test tape
(reference blank tape)
---QZZCRA for Normal
“+ QZZCRX for CrOz
*-QZZCRZ for Metal
Note :
Before measuring and adjusting, make sure of
the playback frequency response (For the
method of measurement. please refer to the
playback frequency response}
Overall frequency response adjustment by recording bias current
Note 1:
On RS-M226. overall frequency response
1S adjusted with tape selector set at Normal
Note 2:
Recording equalizer is fixed
1. Make connections as shown in fig. 12.
- 24 dB signal through
LINE IN. Place the set in record
2. Input a 1 kHz.
mode
Erase head
Record mode
=! vM Oscilloscope
Fig. 10
Overall frequency response chart (Norma!)
50Hz 100Hz 200Hz
300 Hz
500Hz LkHz 2kHz 4kHz 8kKHZ10kHz
Record/playback !
head
TP] (L-CH)
TP2 (R-CH)
R1 (t-CH)
R2(R-CH)
Ground
3. Fine adjust the attenuator to obtain
0.4V LINE OUT output.
+ Make sure that the input signal level
is 24+4dB with 0.45V output voltage
Fig. 11
VRQ (L-CH)
VR10 (R-CH)
LINE
VIVM
——
For overall frequency
response measurement
oscilloscope
VTVM FVM oscscoe
arse ears bias current measurement.
Fig. 12

RS-M226
ITEM MEASUREMENT & ADJUSTMENT
Set the tape selector to Normal, and load the test tape (QZZCRA)
Adjust the attenuator to reduce the input signal level by 20dB
Adjust the AF oscillator to generate 50Hz, 100 Hz, 200Hz, 500Hz, 1 kHz, 4kHz, 8kHz and 10 kHz
(ooo
signals, and record these signals on the test tape
Playback the signals recorded in step 6, and check if the frequency response curve is within the limits
shown in the overall frequency response chart for normal tapes (fig. 11).
(If the curve is within the charted specifications, proceed to steps 8, 9 and 10.)
If the curve is not within the charted specifications, adjust as follows,
Adjustment (A):
When the curve exceeds the overall frequency
response chart specifications (fig. 11) as shown
in fig 13.
fe ee +6dB
+
one = t ct —4dB
—t—4—f ett 608
rae
1 — gap
VkH2 2kHz 4kHz 8kHz1OkHz
Fig. 13
1) Increase bias current by turning VR9
(L-CH) and VR10 (R-CH).
(See fig. 1 on page 3.)
Repeat steps 6 and 7 to confirm
NO
(Proceed to steps 8. 9 and 10 if the curve
1S now within the charted specifications in
fig. 11.)
3) If the curve still exceeds the specifications
(tig. 11), increase bias current further and
repeat steps 6 and 7
8. Switch the tape selector to CrO:.
change test tape to QZZCRX, and
record 50Hz. 100Hz. 200 Hz,
500Hz, 1 kHz, 4kHz, 8kHz, 10kHz
and 12.5 kHz signals
the signals and check if the curve is
within the limits shown in the overall
frequency response chart for CrO»
tapes (fig. 15).
9. Switch the tape selector to Metal.
change test tape to QZZCRZ, and
Then, playback
Adjustment ‘B):
When the curve falls below the overall frequency
response chart specifications (fig 11) as shown
in fig. 14,
4 Ti+ 408
re) ttt + 208
> HOB
3 —150B
Toy ~ 208
i = H 4dB
Pree teed +t tt eae
roy | 8 dB
LkH2 2kHz 4kHz 8kHz10kHz
as, |
oe i +4 54B
Fig. 14
1) Reduce bias current by turning VR9 (L-CH)
and VR10 (R-CH).
2) Repeat steps 6 and 7 to contirm
(Proceed to steps 8. 9 and 10 if the curve is
now within the charted specifications in fig
11)
3) If the curve still falls below the charted
specifications (tig. 11), reduce bias current
further and repeat steps 6 and 7
50Hz 100Hz 200Hz
Overall frequency response chart (CrO2, Metal)
PTT
1kHz 2kHZ 4kHz uly
\12.5 KHz
kHz
0
Fig. 15
record 50Hz. 100Hz, 200Hz, 500Hz. 1 kHz, 4kHz, 8kHz, 1OKHz and 12.5 kHz signals
playback the signals and check if the curve 1s within the limits shown in the overall frequency response
chart for metal tapes (tig. 15).
positions.
* Read voltage on VTVM and caiculate bias current by following formula:
Bias current (A) =
Value read on VTVM (V)
10 (Q)
Then,
10. Confirm that bias currents are approximately as follows when the tape selector is set at different
around 350A (Normal position)
around 450zA (Cr02 position)
around 700A (Metal position)
\ measured at TP1 (L-CH) and TP2 (R-CH)
@® Overall gain
Condition :
+ Record/playback mode
* Tape selector
seanee Normal position
* Input level controls --- MAX
* Standard input level;
MIC «+--+ —72+4dB
LINE IN--- —-24+4dB
Vv
position.
ATT to LINE IN.
A
0.45V.
Using test tape, make recording.
P
OUT on VTVM becomes 0.45V.
Test equipment connection is shown in fig. 16.
ace UNIT into record mode, and tape selector to normal
Supply 1 kHz signal (—24 dB) from AF oscillator, through
djust ATT until monitor level at LINE OUT becomes
layback recorded tape, and make sure the value at LINE
AF oscillator
LINE IN
Record/playback
head
Test tape
Fig. 16
Record mode
Test tape
Playback
mode
ytym
Oscilloscope

RS-M226
ITEM MEASUREMENT & ADJUSTMENT
Equipment : 7. if measured value is not 0.45V, adjust VR5 (L-CH), VR6
+*VTVM _ + AF oscillator (R-CH) (See fig. 1 on).
*ATT * Oscilloscope 8. Repeat from step (2)
+ Resistor (600 2)
» Test tape
(reference blank tape)
-+-QZZCRA. for Normal
@ Fluorescent meter . Test equipment connection is shown in fig. 16.
Condition:
.
As
shown
in
fig.
17,
connect
the
collector
of
Q8 and peak reset terminal.
* Tape selector . Supply 1kHz signal (—24 dB) to the LINE IN
Normal position jack, then press the record button.
+ Input level controls --» MAX _ Adjust the ATT so that the output level at LINE
OUT jack becomes 0.45 V (The input level at
Equipment: ; this condition is termed the standard input Connection
+ VTVM * AF oscillator level) uN cord
* ATT . Adjustment at "—20dB"
A. Adjust the ATT so that input level is —20dB
below standard recording level
B. Adjust VR7 so that the —20dB segment >
lights up in the —20 + 1dB range (L-CH Ly
ONLY) (See fig. 18) SUTETTTTTTETT TTT ET HTT
5.
Adjustment
at
“OdB":
20
(Fak)
6
©
4+
20+
2
00-68:
A. Adjust the ATT so that the output level at Fig. 18
LINE QUT jack becomes 0.45V. MMS
(The input level at this condition is termed vesveseeaserisesisaasssersaseesecsese FOB)
the standard input level.) t SHMUOOUUQUAOUUATOL AUT A UAV ALT AT LAUUHT TUT
. Adjust VR8 so that the +1dB segment 20 (ER) pee nae -2+*0+2 00-628
lights up in the 00.2 dB range of the Fig. 19
* Record mode
Fig. 17
standard input level (See fig. 19). CC
Repeat twice between steps 5 and 6 above. i
. Adjust ATT and check that all segments light SS ITTULTUUEUUMTUUATUUUTOULCUUUU TDCI
vt Pus vrs
PIVTINERYELULASEAS EASE SOEEEEY ET
up when an input signal level is increased to 20 bah airs shee eat
10 dB higher than the standard input level (See ee Fig 20. sc a
fig. 20).
© Dolby NR circuit Dolby circuit frequency response check
Condition: @ Check of the Dolby-B type encoder characteristics
* Record mode . Make connections as shown in fig. 21.
* Dolby NR switch -+- IN/OUT . Set the unit to the record mode. (NR select switch is OUT.)
* Dolby NR select switch . Apply a 1 kHz signal to LINE IN.
++B/C . Adjust the ATT so that the output level at TP3 (L-CH) and TP4 (R-CH) is 12.3 mV.
* Input level controls MAX . The output level at pin 14 should be 0dB.
Equipment: . Set the NR select switch to B, and make sure that the output signal level at pin 14 of IC3 (L-CH) and
*VTVM — * AF oscillator IC4 (R-CH) is +6dB+2.5dB.
* ATT * Oscilloscope . Set the NR select switch to OUT, and adjust the frequency to 5kHz. The output signal level at pin
* Resistor (600 Q) 14 should be OdB. ;
. Set the NR select switch to B and make sure
that the output signal level at pin 14 of IC3 TP3 (L-CH)
(L-CH) and IC4 (R-CH) is 8dB+2.5¢B. re
© Check of Dolby-C type encoder characteristics
9. Repeat steps 1-5 above.
10. Set the NR select switch to C and make sure
that the output signal level at pin 14 of IC3 ;
(L-CH) and IC4 (R-CH) is 11.5dB+2.5dB. fate {ite (L-CH) 2
11. Set the NR select switch to OUT and adjust Ica (R-CH) EN ere
the frequency to 5kHz. The output signal at Fig. 21
pin 14 should be OdB. 9-
. Set the NR select switch to C and make sure
that the output signal level at pin 14 of IC3
(L-CH) and IC4 (R-CH) is 8.5dB+2.5dB.

RS-M226
ELECTRICAL PARTS LOCATION
Q14, 15
5-Core flat cable
White line
aa = Connector [4]
ree (Flat Cable
connecter)
Open the lid of connector G]
in the direction of the arrow
as shown above, and extract
the 5-Core flat cable to
disconnect.
REPLACEMENT PARTS LIST
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.
Ref No. Part No. | Part Name & Description Ref No. Part No. Part Name & Description
ELECTRICAL PARTS E7 QuS1961S Flat Cable Connector
E8 QJUT1090 Pin Terminal-A
E1 QWY4122Z Record/Playback Head (Test Point)
E2 QWY2138Z Erase Head EQ SJT777 Pin Terminal-B
E3 (AC Power Cord)
[D] A RJA23ZC AC Power Cord E10 NO39 Heat Sink
[For all European areas except United Kingdom.}
([B)A QFC1205M AC Power Cord E11 QJS1923TN 9 Pin Socket
{For United Kingdom.] E12 QJT1054 Contact
4 QSiFLOO6F FL Meter E13 QJS1921TN 3 Pin Socket
5 QJP1921TN 3 Pin Post E14 A QTF1054 Fuse Holder
6 QJP1923TN 9 Pin Post

BLOCK DIAGRAM
Recording System(L-CH ONLY)
RS-M226
INPUT SELECT SWITCH =_>— > ~
LINE LINE <—»® MIC
$2-4 $2.2
LEVEL
CONTROL
a oT> | ©
pr sts] Ly
Pp VR5 RECORDING
FOAM GAIN ADJUSTMENT VR
MICROPHONE AMP
RECORD/PLAY
BACK HEAD
= §
VR10 BIAS
Y- CURRENT @) )
ADJUSTMENT VR Metal
> e (6) J x $6-3
Cro,
[-—} O ©
TAPE SELECT
is Se oe Ee 5 0 fo SWITCH
Normal
07 RECORD
INDICATOR
a
ERASE HEAD |
Metal
-O 6-1
cro,
O
|
!
|
|
|
|
|
Le
BIAS OSC
Playback System (L-CH ONLY)
RECORD/PLAYBACK
HEAD
1C1 PLAYBACK EQ AMP
PLAYBACK
GAIN
ADJUSTMENT
a
MUTING FF/REWIND
CONTROL |
MUTE
i
r
FF/REWIND
CR
NETWORK
MUTING SWITCH (70ys) |
|
|
L
Cro,
Normal ©
O Metal
O
S6-2 i
TAPE SELECT SWITCH
Power Supply System
1C7 a
METER &
HEADPHONES
AMP
Th
VOLTAGE
REGULATOR
DOLBY NR
SECTION
103-6
FL METER
SECTION
IC8
Q15
VOLTAGE
REGULATOR
NOTE:
* Dolby NR...... OFF
° (mmm ) this arrow indicates the flow of
the recording signal.
¢ (<>) ) this arrow indicates the flow of
the playback signal.
MUTING
CONTROL
Q11—13
FL METER
FILAMENT
(\
D13—16 |
RECTIFIER
CAPSTAN
MOTOR
T HEADPHONES (2)
~~ V
METER & HEADPHONES
RS-M226
DOLBY SYSTEM (L-CH ONLY)
LINE
OUT
Dolby-B
Encode
MIC.
MIC IN AME Ic3 section to check the frequency Mien tiie
iit NE6S4N response of the Dolby circuit in the O
HEADPHONES AMP A +
vRi Ics illustration.
NE652N
LINE IN 5 () q
O oO C RECORD
AMP
MPX FILTER (2)
HEADPHONES
JACK
METER
HEADPHONES
LINE OUT
Q8, 9
PEAK HOLD O
SET/RESET
UI
+4
H.F—O—O—0O
>
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HIGH PASS FILTER
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DOLBY NR CIRCUIT
FREQUENCY RESPONSE
HEADPHONES Pee 1kHz: +6dB+2.5dB
JACK
Ty 5kHz: + 8dB+2.5dB
Dolby-B Decode
VR5
Q8, 9
PEAKHOLD
SET/RESET
METER
HEADPHONES
LINE OUT
ddNS YMd
AsO/0/8
x
POWER
ON/OFF
SWITCH
~~ &£ HIGH PASS FILTER
PB EQ AMP
Refer to Item © “Dolby NR circuit” of
the measurement and adjustment
Dolby-C Enca
LINE IN
(G O
E MPX|
METER
HEADPHONES.
LINE OUT
(G
Spectra
skewing
networ!
LS
Low level stage
integrating
filter
Anti-satur:
Low level stage
high pass filter
REC EQ AMP
Dolby-C Deca
METER
HEADPHONES
LINE OUT
Spectral
skewing
network
Low level stage
integrating filter
PB EQ
Low level stage
high pass filter
Anti-Saturation filta

RS-M226
LINE OUT
METER &
HEADPHONES AMP
HEADPHONES
JACK
~~
Q8, 9
PEAK HOLD
SET/RESET
FL METER DRIVE
FL METER
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LINE OUT
©
&
HEADPHONES
HEADPHONES
AMP
JACK
—vV,
Q8, 9
PEAKHOLD
SET/RESET
POWER
ONIOFF
~1. SWITCH
C200
RS-M226
DOLBY SYSTEM (L-CH ONLY)
Dolby-B
Encode
Refer
to
Item
©
“Dolby
NR
circuit”
of
the measurement and adjustment
AMP section to check the frequency
MIC IN Ic3 babahietes
NE654N response of the Dolby circuit in the
vRi Ics illustration.
NE652N
LINE IN (1) q
O O e RECORD
g
; MPX FILTER a i
NeTER SS
es l @
HEADPHONES (4) + > <2)
LINE OUT ar<d G)
N
ee
cE
all
@
Yl
BUFFER AMP <6 |
i (4)
3
G)
(6)
HIGH PASS FILTER
DOLBY NR CIRCUIT
FREQUENCY RESPONSE
Sy
ddNS YMd
©
Low level stage
integrating filter
Low level stage
high pass filter
TT)
i
>=
o—o—o-4
1kHz: +6dB+2.5dB
VR5
REC
EQ
AMP
5kHz:
+
8dB+2.5dB
=
Dolby-B Decode
IC3 1c5
NE654N
NE652N
METER
HEADPHONES
LINE OUT
IddNS YMd
Z|
~~ & HIGH PASS FILTER Low level stage
integrating filter
PB EQ AMP
Low level stage
high pass filter
rd
Refer to Item © “Dolby NR circuit” of
the measurement and adjustment
section to check the frequency
response of the Dolby circuit in the
illustration.
Dolby-C Encode
MIC IN MIC AMP.
IC3
NE654N
VR1
1c5
</
£
LINE
IN
0
NE652N
HIGH
LEVEL
STAGE
: -
MPX
FILTER
High
level
stage
ae
high
pass
filter
METER
HEADPHONES High level stage
integrating filter
LINE OUT High level stage
main chan signal
C—O 0
“Kr I<]
©) o—é @)
High level stage
side chain net work
Spectral
skewing
network
Low level stage
side chain net work
Low level stage
Low level stage
main chain signal
integrating filter
Anti-saturation filter
os Bs oe
ie
=
a
=o) ile
)——-©)-—®
Low level stage
i
high pass filter
Ma ta pe ig we ee le 4
LOW LEVEL stage”
DOLBY NR CIRCUIT FREQUENCY RESPONSE
kHz: +11.5dB+2.5dB $ # —
Dolby-C Decode
Ic3 1c5
HIGH LEVEL
NE654N NE652N STAGE
High level stage signal
High level stage
high pass filter
METER
High
level
stage
’
integrating
filer
HEADPHONE:
LINE
OUT
High level stage main
chain signal
TddNS YMd
XK
4sd0/0/8
High level stage
side chain network
Spectral
skewing
network
Low level stage side
chain network
Low level stage
integrating filter
Low level stage
high pass filter
Anti-Saturation filter
LOW LEVEL STAGE