Casio CTK-431 User Manual

CTK-431

INDEX

100 SONG BANK KEYBOARD

MUSICAL INFORMATION SYSTEM SONG BANK CONTROLLER

POWER/MODE

OFF

FINGERED CASIO CHORD NORMAL

MAIN

VOLUME

PHONES/ DC 9V

OUTPUT

SYNCHRO/

START/

FILL-IN

STOP

TEMPO CHORD BOOK

ACCOMP VOLUME

OUTIN

MIDI

m 7 M7 dim

01234 56789

aug sus4 -5 add9 CLEAR

SONG BANK

MAIN VOLUME

TONE

RHYTHM STATUS

TEMPO

MUSICAL INFORMATION SYSTEM

TONE SONG BANK

RHYTHM

TRANSPOSE/ TUNE/MIDI

REW STOP FF

LEFT

ON/OFF

SONG BANK CONTROLLER

ELECTRONIC KEYBOARD

RIGHT ON/OFF

CTK-431

CONTENTS

Specifications ................................................................................................................................... 1

Block Diagram.................................................................................................................................. 2

Circuit Description ............................................................................................................................ 3

Adjustment ....................................................................................................................................... 7

Major Waveforms ............................................................................................................................. 8

Printed Circuit Boards ...................................................................................................................... 9

Schematic Diagrams ...................................................................................................................... 10

Exploded View ............................................................................................................................... 14

Parts List ........................................................................................................................................ 15

SPECIFICATIONS

GENERAL

Keyboard: 49 standard-size keys, 4 octaves Tones: 100 Polyphony: 12 notes maximum (6 for certain tones) Auto accompaniment

Rhythm patterns: 100 Tempo: Variable (236 steps, = 20 to 255) Chords: 2 fingering methods (CASIO CHORD, FINGERED) Rhythm controller: START/STOP, SYNCHRO/FILL-IN Accomp volume: 0 to 9 (10 steps)

Song bank

Tunes: 100 Controllers: PLAY/PAUSE, STOP, REW, FF, LEFT ON/OFF, RIGHT ON/OFF

Musical dictionary

Name display: TONE, RHYTHM, SONG BANK name/number, keyboard settings name/value Tempo: Tempo value, metronome, synchro standby, beat indicator Chord: Chord name, Chord form Fingering: Fingering indicators, parts, pedal (The pedal indicator is for received MIDI

data only.) Song bank status: PLAY, PAUSE, REW, FF Staff: 4 octaves with sharp and flat indications Keyboard: 4 octaves

MIDI: 5 multi-timbre receive Other functions

Transpose: 12 steps (–6 semitones to +5 semitones) Tuning: Variable (A4 = approximately 440 Hz ± 50 cents) Volume: 0 to 9 (10 steps)

Terminals

MIDI terminals: IN, OUT Phones/Output terminal: Stereo standard jack (Output is monaural.)

Output Impedance: 60 Ω

Output Voltage: 5 V (RMS) MAX Power supply terminal: 9 V DC

Power supply Dual power supply system

Batteries: 6 AA-size batteries Battery life: Approximately 2 hours (SUM-3/R6P)/4 hours (AM3/LR6) AC adaptor: AD-5 Auto power off: Turns power off approximately six minutes after last key operation. Can be

disabled manually.

Speaker output: 3.0 W (Output is monaural.) Power consumption: 9 V --- 7.5 W Dimensions (HWD): 958 × 310 × 132 mm (37-3/4 × 12-3/16 × 5-3/16 inches) Weight: Approximately 3.5 kg (7.7 lbs) (without batteries)

ELECTRICAL

Current drain with 9 V DC:

No sound output 200 mA ±20 % Maximum volume 750 mA ±20 %

with 12 keys C1 to B1 pressed in Synth-Lead 1 Volume: 9 (Max.)

Phone output level (Vrms with 8 Ω load each channel):

with key A4 pressed in Synth-Lead 1 95 mV ±20 %

Speaker output level (Vrms with 4 Ω load each channel):

with key C4 pressed in Synth-Lead 1 1050 mV ±20 %

Output level (Vrms with 47 KΩ load each channel):

with key C1 pressed in Synth-Lead 1 1100 mV ±20 %

Minimum operating voltage: 5.7 V

— 1 —

— 2 —

CPU

MSM 6755C-17

LSI1

Keyboard

Buttons

LCD

LCD Driver

KS0066U-10B

LSI3

Reset IC

IC1

Oscillator

X1, Q1

Power Supply Circuit

Q101 ~ Q103, D104

Power Amp.

LA4598

IC101

Filter

Q105

Speaker

(L)

Speaker

(R)

Phones/Output

AVDDVCC DVDD

APO

MD0 ~ MD7

MA0 ~ MA17

DC + 9 V IN

DB4 ~ DB7

COM1 ~ COM16

SEG1 ~ SEG40

RS R/W E

KO8 ~ KO12

KI0 ~ KI6

KO0 ~ KO7

ROM(2M-bit)

UM23C2101M

7384/Q

LSI2

Power Switch

BLOCK DIAGRAM

CIRCUIT DESCRIPTION

KEY MATRIX

KI0 KI1 KI2 KI3 KI4 KI5 KI6

KO0 C2 G#2 E3 C4 G#4 E5 C6

KO1 C#2 A2 F3 C#4 A4 F5

KO2 D2 A#2 F#3 D4 A#4 F#5

KO3 D#2 B2 G3 D#4 B4 G5

KO4 E2 C3 G#3 E4 C5 G#5

KO5 F2 C#3 A3 F4 C#5 A5

KO6 F#2 D3 A#3 F#4 D5 A#5

KO7 G2 D#3 B3 G4 D#5 B5 KO8 —+0

KO9 321

KO10 654

KO11 98

KO12 FF Right

Chord

Play/

Pause

Tempo Tempo Volume Volume

Down Up Down Up

Start/ Synchro/ Chord Accomp

Stop Fill-in Book Volume

Transpose/ Song

Tune Bank

Rhythm Tone

Fingered CASIO Normal Power Off

Stop Left Rewind

NOMENCLATURE OF KEYS

C#2 D#2 F#2 G#2 A#2 C#3 D#3 F#3 G#3 A#3 C#4 D#4 F#4 G#4 A#4 C#5 D#5 F#5 G#5 A#5

D2 E2 F2 G2 A2 B2 C3 D3 E3 F3 G3 A3 B3 C4 D4 E4 F4 G4 A4 B4 C5 D5 E5 F5 G5 A5 B5 C6

— 3 —

CPU (LSI1: MSM6755C-17)

The CPU reads sound data from the ROM in accordance with the pressed key and the selected tone; the CPU can read rhythm data simultaneously when a rhythm pattern is selected. Then it provides the left and the right channels’ waveforms separately, by converting the data into the waveforms with two built-in DACs. The CPU also controls key and button input. The following table shows the pin functions of LSI1.

Pin No. Terminal In/Out Function

1 MA14 Out Address bus

2, 3 NCO — Not used

4 ~ 19 MA0 ~ MA13 Out Address bus

13 MRDB Out Read enable signal 17 MCSB — Not used

20 ~ 27 MD0 ~ MD7 In/Out Data bus

28, 29 NC1, NC2 — Not used

30 DGND In Ground (0 V) source 31 DVCC In +5 V source

32, 33 XTLO, XTLI In/Out 20 MHz clock input/output

34 NC3 — Not used 35 RSTB In Reset signal input 36 P24/RXD — MIDI signal input 37 P25/TXD — MIDI signal output 38 NMI In Power ON signal input. Connected to +5 V. 39 APO Out APO (Auto Power Off) signal output 40 NC4 — Not used 41 REFH Out Terminal for the internal DAC

42, 43 NC5, NC6 — Not used

44 DAOR Out Sound waveform signal output 45 NC7 — Not used 46 AVdac In +5 V source for the internal DAC 47 DAOL Out Left channel sound waveform output 48 REFL Out Terminal for the internal DAC and ADC 49 AGdac In Ground source for internal DAC 50 AGadc In Ground source for internal ADC 51 ANI In Not used 52 AVadc In +5 V source for the internal ADC 53 NC8 — Not used 54 MOD0 In Mode selection terminal. Connected to +5 V.

55, 56 MOD1, MOD2 In Mode selection terminal. Connected to ground.

57 P40 — Not used

58 ~ 64 KI0/P30 ~ KI7/P36 In Terminals for key/button input signal

65 KI7/P37 — Not used

66 ~ 73 KO0/P50 ~ KO7/P57 Out Terminals for key scan signal

— 4 —

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