KORG

CONTENTSf,SPECIFICATIONS

27.

—STRUCTURAL DIAGRAMBLOCK DIAGRAM
CIRCUIT DIAGRAM
PC, BOARD
MAIN CIRCUIT EXPLANATIONS ADJUSTMENT PROCEDURE

8.

PARTS LfST2.

3.

4.
5.
6.

3-4j-7— 9*1618

ICEIO ELECTRONIC LABORATORY CORPORATIONTOKYO/ JAPAN1.

SPECIFICATIONSKEYBOARDDRAWBARS x 9PRESET-DRAWBARSrB a-r + g + J aja

PERCUSSION *++ U>
ROTARY EFFECT....
TONE CONTROLSTUNEVOLUME.
OUTPUTSi+1 K + lpti bi-p p + *- Tfra*i + *Ti r* + -fri e»1* + B + *g § + , pp-tb + t it-spt iS-!

-• I. II. 111. Drawbars-' .. .T.

it! l-k-khh - + H |«TI P 4-1-1 4*1k h. k%i m*.

i-M + R-P-*

4', 2-2/3', Percussion Volume, Percussion

Decay• Bass, Treble, Overdrive....* Tune (+S0 CENTS).

& Volume, key Click Volume• Signal Outs *2 (High /low). Accessory Send...• Power1.• Accessory Return, Rotary Effect (Slow /Fasl)• ii49(W)x 137(H) x 315(D) mm

DIMENSIONS...
,, i +r4l

On, Fasl

INPUTS..........

WEIGHTACCESSORIESPOWER CONSUMPTION• C — C/61 keys
• 16‘, 5-1/3', S', 4', 2-2/3', 2', 1-3/5'. 1-1 /3\ 1*+! F+++‘'l+tir + .t-'®

10.5kg.• Dust Cover. Connection Cord.• Voltage (Local Voltage, 50/60Hz), Wattage (5W)2

2.

STRUCTURAL DIAGRAM

Item

Item

Part Name

Item

Part Name

Cabinet11.

23.

Service caution seal

Part Name

Remarks

Bottom12

3.

Rear panel

13.

4.

Control panel mounting

14.

5.

Draw bar holder

15.

PS knob (small)
Rotary kn^bLever SW. mask
Selector SW mask
Cord stopper

6.

Radiation board

18.

7.

KORG Mark (Small)

19.

8.

Oontrol panel

20.

9.

Selector SW knob

21.

1.

2.

10.

Draw bar knob.

22.

Remarks

Remarks

Item

Part Name

33.

Keyboard

Model number plate

34.

Control circuit board

25.

Strain release bushing

35.

Main circuit board

26.

Phone Jack

36.

R.E. Circuit board

27.

Rotary variable resistors

37.

Selector SW

Fuse caution seal

28.

Rotary variable resistors

38.

Earth (ground) seal

Fuse seal

29.

Rotary variable resistors

39.

Sealed cover

Serial number seal

30.
31.

Power transformer
Lug board40.

KORG Mark seal

41.

Aluminum film
Aluminum film

32.

Draw bar

42.

Metal fitting of stand

Wiring caution (large)

324,Remarks

-3.

BLOCK DIAGRAM

Tcotajt

ToiJt CflNitPW-Flhl^U VOL

Tltt-p'u’E

OVEJ?

t>Fn/E

PncH
Coht pq

PWWEiIRS

— —w

w-“

PefcCLi^itfl*41 tlr<]
**<nt

A’F

:

1a * d4.

CIRCUIT DIAGRAM

KLM-244

Tt KLM24S

5KLM-245

KLM-246

5.

PC BOARD

Kano k-mi

KLM-M41

7B6.

MAIN CIRCUIT EXPLANATIONSBecause the tone circuit is of the programming type, it can be used in many different ways.

However, here is only explained hew the circuit is used in the CX-3.
1*Tone circuit

1C-SM304A is 3 data processing 1C designed forcontrol signal. After passing through the P/Selectronic organ applications.

{parallel-to-seriesJ converter, the data is stored as

Data from the 61 keys on the keyboard is con-D

verted from a parallel control signal into a series

SM-305B.

intheSR

T - CLOCKU “ INTERROGATION (TRANSFER]

F*Hn 1-1

Drtz ftmp"SM-305A andwith storage ofiu--

rmfcpmDuri 1-1 T ft U

T = The clock puise counts from 1 to 65 bits. 4

U - Simply speaking, the transfer pulse identifiesof those bits are for footage group programming

the beginning of the series.

and 61 bits are for keyboard programming. Referto chart 1-2.

Programming bits

Sutmimgh«it puts for p rogrwnrmng

Footsg*group

OSSM305

FBIPB2

PB3

PB4

HM

H

H

H

H

H

S95!CTRCOr
H

VDD

Proyimmi^ bfta

SM305EFBIESsa57

SumminiKHJtputs for programming

PB3

PBSPS4HM

H£1

E2£4rr

S46

S39

S45

S3S

S3S

$42VDD

HE3[Designation ofprogrwnrninff
bits for SM-304

Cliart 1*2

9Prof ramming$43FoctM
S3?

544

r

1

TO FixedFiller

1C SM-305

indudes shift register, octave divider.

and harping matrix functions.

There the 12-tone octave divider and sound is
produced in accordance with the data. Refer tofigure 1-2.

The data that had been transferred to the shiftregister

is

now transferred to the harping matrix..

Harping Matrix

SM-305A produces 3 footage groups.
W-3054-1

Foot*?* group-3(But without10-2/3')

4Foot*?* Group '1r

*2/3.

r

2 2/3

5-1/3'

Futig* Group-e6-1/3*

4'Foots?* Grotfp-3

16'

10-2/3'8'

1AfT

SW-30S4-IF

Footage gnup-t

SM-3068

Foot*?* group-4r{Refer to the Harping matrix

SM-305B produces 2 footage groups.

(But without21 %' or 1/2’)— footage groupchart)

Foot*?* 0 roup4

1-4/5'

V

213'

1/7’

in other words, the top octave divider produces

Foot*?* Groups

4/5'

1/3'

1/4'

1/8'

12 frequencies - C# {4434.96Hz) D, Dtf . . . B,C (8372Hz) etc. For example, to get 4' C, which
isFootage groups usedbelow.

inthe CX-3 are as listed

4 octaves lower, the 4186Hz is divided by 32to obtain

130,81Hz (C), This note centeredaround VDD/2 is sent to tone out and from there
to each of the fixed filters.

10SM-305A-1

1Harping matrix for footage group 1Keys

32.70Hz

C,—Tones

65.47

E

130.81t

2fi1.$3c’

523JZ5C

1046.5E:

5%2083

C*

418$

C*

4434.96

t~T0S8372
S-outputswTftinwr* than one ocftve; SlO + Sl1 = Stff
S21 + S22-S21'

11

SA-305AI

Harping matrix for footage group 3Keys
MJ^

34%

32.70H*: C,ITefws

65.41

C

130.81

C261.63t

623,25C

1.46.5c

11W*V 2t}
a*

C*

2003

4186
4434.96T
058372S-output^ with rrKjrp than Qfws octive:

S1D+311— SIP$21 + S2a«S2T

12

SM305B

Harping matrix for footage group 4K»y$82.70Hz

C,I

Tones

65.41

C523-25

C-11046.5^2—"**'e

*

2093

4186

c4434.96

i5T0S8372
froutptrts with more th*n oneoctftve

S29 + £30 = S 29
S40 + S41 = S40'13

2.

Filter circuitry

There are fixed filters for each tone; separateoutputs are provided for presets and drawbars,
the selector buttons determine which gate isoperated to pass the signal on to the mixer.

F*gui* 2-1

3.

Filt*nKey-Click circuit

White noiseeffect.

isused to produce the key<lick

The SM-305A THKF {multiple trigger)

controls the effect.

14

4.

Perm is ion circuit

The percussion circuit uses 4' and 2-2/3’ signals.
The envelope signal which controls the effect isproduced

withtheSM-305B KD (key-down}

single trigger.

toMIXER

5.

Rotary Effect circuit

Two 3BD circuits are used to produce the rotaryeffect.

The BBDs are IC-MN3004, Refer to thediagram

FROMTowe

15

7.

ADJUSTMENT PROCEDURE

Caution: Very precise adjustments have been made at the factory, so be careful not tochange any setting otehr than that which is out of order.

Circuit

Board No,SECTION

ADJUSTadjustment

SETTINGS

Oscilloscope

Vr Nq,rTUNE- CENTERSELECTOR- DRAWBARS
KLM-244DRAWBARSPITCH

Play A and adjust
to obtain a 0 c*ntr«adir>g.

VR -1-S'
SIG OUT- WTTOAWT-IOA^S/M-METERSlGOUHHil- OSCILLOS

SELECTOR- DRAWEARSNOISE GAINDRAWBARS-0Adjust to gat 0.5V
-0.7V key dfiefc
sound when a levy

Vfl-7

is plsy«d.

KEVCUCK-MAXIKEY OHVOL - MAX

KLM24SSIG OUT! Hi)- OSCILLQ.S

P4'+W

PERCUS VOL— MAX
FERGUS DE-

CAY - MAXPERCUSGAINPERCUSSION—4SELECTOR- DRAWBARSrF
ON04'

Adjujt so th#ra is a

7:1~S;1 r1t» betwBen percussion 4and drawbars 4'.

F

VR 4J

DRAWBARS-4-ROTARYLFO (LQW)

LFO (HIGH)

EFF£ - FAST

Adjust to obtainICS-1— f .counter

14Sfnj« Trading,Vft-6obtsin

VR -5

JCfi

— fLoountar:

1 30rres#c

rmading.

KLM-246©IAS [LOWJ

C44’ Digits

Adjust to obtain

I

BIAS (HtGHI

iCl-S-DigvtaJ

Adjust tq obtain
6.00V rwdEng,

6.0GV reading.

AM-H
*VR-3
VR-1
VR-2

The AM-H adjustment controls the high range volume fluctuation when the rotating speakereffect is turned on. Listen to the sound to confirm proper adjustment.

16Trimmer positions (reference chart)

NOISE GAIN

ooo_ o©
SEROUS GAINo.o©

vne

17a PARTS LIST
{Refer to structural diagram for parts list.)

PARTS

SPECIFICATIONS

NAME

PARTS

SPECIFICATIONSNAMECERAMIC CAPACITORS
561(560 pF)

ECK-RE104ZFZ (0,1 jjFJ

ELECTROLYTIC CAPACITORS
0-22* /50V
0.47

10/ 16100
1000 /6.3V
220 / 161000 / 6,3100 /IS
2200 / 25

TRANSISTORS

0.00120.00150.0022

2SC945 LK
2SC945
2SC1215T
2SC644R
2SC13B4900027

2SA733AK

MYLAR CAPACITORS
50V

D.DQljjF k

0.00330.003900047
0.0063

DIODES
1S1555isiess

0.01

0.012

00220033

1C$fw$-304A

0.047

SM305A

0.06S

SM-3G5B
NE-555

0.082
0.16
0.056
0,15
0.015
0.039

S- 50241

MC- 14069
4458
MC-14046
MN-3004*iPC 324

STYROL CAPACITORS
47 pF S (5%)
120(1%)

14312 (73121

SEMI FIXED RESISTORS
4?0ftB150

HI 051

10KB
220

1MB
100KB
1KB

KEYBOARD
ESK307V (61 key)
FUSE
250V

0.5A

LUG BOARD
L-12066P

ISspecifications

FARTSQ'TY

NAME

CONNECTORSPOTENTIOMETERS
K O-t 31132

CX3^11VOLUME

1KEY CLICK
TUNE
OVER DRIVE

112212311BASS101

1911711TREBLEPERCUS DECAYFERGUS VOL

41

121122192
32i

SLIDE

1i!

10P

9743

EVHL0AS20B15
EVH-LOAS20A55
EVH-LOAS20A14

S401XKA10KC
KHCl 1901 with LED

ROTARY KNOB
Rotary knob (Large) 1S£
Rotary knob
lor PS{Bl 3P -SHF-1

2(B12P-SHF-1

3(B9BSHF1I

2(B3P-SHF-1}(B2P-SHF-1)

1

DRAWBAR KNOB
TsiO.1
Drawbar knob 5-1/3" >Drawbar knob 2-2/3" 2Drawbar knob 1 -3/5' Browns
34Drawbar knob 1-1/3'
5Drawbar knob 15'^.

2

BOTTOM ENTRYfT]VOLUMEDRAWBAR x

SELECT SWITCHSE LECT X 8

TOP ENTRY
13P
12932P

EVC-B05PISBI4
EVH-BMA803A1
EVH LOAS20B14
EVH-LOA$20ei6
EVH-L0AS20B15121

TRC-1
100X
V

PANEL INSTRUCTION STANDARD(BE10P-SHF1)(SE9P-SnF*1(BE7P-SHF-1)<BE4P-SH F-l J<BE3P-SKF-t

Drawbar knob 8' ”
Drawbar knob 4 Drawbar knob 2'
Drawbar knob 1*1rd1].

1!

Ivoryb67891

PRINTED CIRCUIT BOARD

Select knob (gray)(KLM244){KLM246)(KLM246)

1

SR-6W-1

3

Select knob (Brown)

1
1

PHONE JACKRETURNOTHERS x 4

BUSHING

0929
0983

POWER TRANSFORMER
JA-221-12
JB-221-12

I*1

BUSHING
4K-4
SP-433--19