Casio CTK-50 User manual

ELECTRIONIC KEYBOARD

CTK-50

(without price)

— 2 —

ELECTRICAL Nominal Limit

Current drain with 9V DC:

No sound output 50 mA 50 mA ±30%

Maximum volume 515 mA 515 mA ±30%

with keys C1, D1, E1 and F1 pressed

in Car-Horn tone, Volume; Maximum

Sound Pressure Level at 10 cm away from speaker: 108 dB 108 ±10 dB

with key C4 pressed in Car-Horn tone

Volume; Maximum

Minimum operating voltage: 5.8 V 6.0 V

GENERAL

Number of keys: 49

Polyphonic: 8-note

Preset tones: 100

Auto-rhythms: 100

Auto-accompaniment: CASIO Chord/Fingered

Demonstration tune: Classical Medley

Built-in speakers: 10 cm dia. 2.0W Input Rating: 1 pc.

Terminal: AC Adapter Jack (DC 9 V)

Power source: 2-way AC or DC source

AC: AC adapter

DC: 6 AA size dry batteries

Power consumption: 6.0 W

Dimensions: 79 x 766 x 269 mm (HWD)

(3-1/8 x 33 x 10-5/8 inches) (HWD)

Weight: 2.8 kg (6.2 lbs) excluding batteries

SPECIFICATIONS

CONTENTS

Specification.............................................................................. 2

Block Diagram........................................................................... 3

Circuit Description ..................................................................... 4

Troubleshooting ........................................................................ 7

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

Schematic Diagrams ................................................................. 9

PCB View ................................................................................ 11

Exploded View ........................................................................ 12

Parts List ................................................................................. 13

— 3 —

BLOCK DIAGRAM

KO0~KO9

KI0~KI7

Keyboard

Switches

Oscillator

Q301, X301

VDD +5 V

Power supply circuit

Q101, Q102, D102

VC +9 V

Amplifier

A4598

IC101

Speaker

Filter

Q201

CPU

MSM6387-13

LSI201

Main Volume

AVDD +4.8 V

— 4 —

NOMENCLATURE OF KEYS

CIRCUIT DESCRIPTION

KEY AND SWITCH MATRIX

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

F3 G3 A3 B3 C4 D4 E4 F4 G4 A4 B4 C5 D5 E5 F5 G5 A5 B5 C6

D#3

C#3A#2G#2F#2

D#2

C#2

C2 D2 E2 F2 G2 A2 B2 C3 D3 E3

KI0 KI1 KI2 KI3 KI4 KI5 KI6 KI7

KO0 0 1 C2 C#2 D2 D#2 E2 F2

(KC1)

KO1 2 3 F#2 G2 G#2 A2 A#2 B2

(KC2)

KO2 4 5 C3 C#3 D3 D#3 E3 F3

(KC3)

KO3 6 7 F#3 G3 G#3 A3 A#3 B3

(KC4)

KO4 8 9 C4 C#4 D4 D#4 E4 F4

(KC5)

KO5 Tone Rhythm F#4 G4 G#4 A4 A#4 B4

(KC6)

KO6 Tempo Tempo C5 C#5 D5 D#5 E5 F5

(KC7) Up Down

KO7 Start/ Fill-In F#5 G5 G#5 A5 A#5 B5

(KC8) Stop

KO8 Demo C6

(KC9)

KO9 Normal Fingered CASIO

Chord

— 5 —

Pin No. Terminal In/ Out Function

1, 2 TEST1, TEST2 Not used. Connected to ground.

Power ON reset terminal. When the power switch is

3 RESET In turned on, the terminal receives a low level signal and

the internal circuits of the LSI are initialized.

4 AVDD In +5 V sorce for the built-in DAC

5 OUT Out Sound waveform output

6 AGND In Ground (0 V) source for the built-in DAC

7 GND In Ground (0 V) source

8 COSI In 21.725 MHz clock pulse input

9 COSO Not used.

10 VDD In +5 V source

11 ~ 18 KI0 ~ KI7 In Input terminals from keys and switches

19, 20 KO11, KO10 Not used.

21 ~ 30 KO9 ~ KO0 Out Key and switch scan signal outputs

CPU (LSI201: MSM6387-13)

The CPU contains a sound data ROM and a DAC (Digital to Analog Convertor), and it provides a sound

waveform in accordance with the pressed key and the selected tone.

The following table shows the pin functions of LSI201.

FILTER BLOCK

Since the sound signal from the CPU is a stepped waveform, the filter block is added to smooth the

waveform.

AVDD

C203

Q201

2SC1740SQ

R202

C202

AG AG

R204

R203

C201

To main volume

From CPU

— 6 —

Pin No. Terminal In/Out Functiion

1 Power GND In Ground (0 V) source

2 Ch1 B.S. Out Terminal for a bootstrap capacitor

3 Ch1 OUT Out Channel1 output

4 VCC In +9 V source. Connected to the power source directly.

5 Ch1 N.F. In Negative feedback input

6 Ch1 IN In Channel1 input

7 D.C. Out Terminal for a decoupling capacitor

8 Pre GND In Ground (0 V) source

9 Standby In Power control signal input. 0 V: OFF, +9 V: ON

10 Ch2 IN In Channel2 input

11 Ch2 N.F. In Negative feedback input

12 Ch2 OUT Out Channel2 output

13 Ch2 B.S. Out Terminal for a bootstrap capacitor

14 NC Not used.

POWER AMPLIFIER (IC101: LA4598)

The following table shows the pin functions of IC101.

11 13

Input

Amp. Pre-drive

Amp. Power

Amp.

TSD protector

Stand by

Bias circuit

Input

Amp. Pre-drive

Amp. Power

Amp.

Ch1 IN

Ch1 N.F.

Pre GND

D.C.

Ch2 IN

Ch2 N.F.

Ch2 B.S.

Ch1 OUT

Power GND

VCC

Standby

Ch2 OUT

Ch2 B.S.

Internal Block Diagram of IC101

— 7 —

Q101

2SD1858Q,R R116

D102

MTZ6.2A

R101

D103

LED101

D101

Power Switch

VDD (+5.5 V)

VC (+9 V)

DC +9 V

Input

DG AG DG DG AG

C102

R115

R114

OFF Q102

2SC1740SQ D201

R208

AVDD (+4.8 V)

POWER SUPPLY CIRCUIT

The power supply circuit regulates two constant output voltages VDD (+5.0 V) for the CPU and the oscilla-

tor, and AVDD (+4.8 V) for the analog circuit.

TROUBLESHOOTING

Nature of Trouble Faulty Block Cause/Remedy

No power Power supply circuit Faulty Q101. Replace Q101.

Faulty D102. Replace D102.

Power switch Poor contact. Clean the contacts.

Power jack (J101) Open J101 or poor soldering. Replace

J101 or resolder.

No sound at all Power Amp (IC101: LA4598) Open or shorted IC101. Replace IC101.

CPU (LSI201: MSM6387-13) Faulty LSI201. Replace LSI201.

Oscillator Faulty Q301. Replace Q301.

Open X301. Replace X301.

Certain keys or switches Key and switch matrix Open circuit on KO or KI line.

do not function Replace keyboard PCB assembly.

CPU (LSI201: MSM6387-13) Faulty LSI201. Replace LSI201.

A certain key or switch Key and switch matrix Dust on the contact.

does not function

— 8 —

MAJOR WAVEFORMS

Clock pulse COSI

MSM6387-13 pin 8

Key scan signal KO0

MSM6387-13 pin 30

Key scan signal KO1

MSM6387-13 pin 29

Sound signal output

MSM6387-13 pin 5

Filter output

Emitter of Q201

Power amp input

LA4598 pin 6

Power amp output

LA5498 pin 3

Tone : Flute (No.13)

Key : A3

Volume : Maximum

50 ns

CH1: 1V

2 ms

CH1: 5 V

–CH2: 5 V

–

2 ms

CH1: 50 mV CH2: 0.5 V

CH1: 50 mV CH2: 50 mV

2 ms

CH1

CH2

CH1

CH2

CH1

CH2

— 9 —

SCHEMATIC DIAGRAMS

Keyboard PCB

— 10 —

Main PCB Notes:

1. All capacitance values are indicated in "µF" (p=10-6 µF).

2. All resistance values are indicated in "Ω" (k=103Ω, M=106Ω).

8.9 5.9 5.0

5.3

0.3 0.9

2.2

2.4

4.7

1.8

Other manuals for CTK-50

Table of contents

Other Casio Electronic Keyboard manuals

Popular Electronic Keyboard manuals by other brands

Yamaha

Yamaha PortaTone PSR-225GM owner's guide

Behringer

Behringer U-CONTROL UMX49 user manual

Yamaha

Yamaha Portatone X2500 owner's guide

Yamaha

Yamaha Portatone PSR-100 owner's guide

Keith McMillen Instruments

Keith McMillen Instruments K-Board Pro 4 Get started

Yamaha

Yamaha PortaSound PCS-30 owner's guide

Roland

Roland Juno-6 Operation manual

McGrey

McGrey 6170 user manual

Yamaha

Yamaha PortaTone PSR-41 owner's guide

HDC

HDC Kurzweil KP300X user manual

Akai

Akai MPK88 quick start guide

Waldorf

Waldorf IRIDIUM quick start

Yamaha

Yamaha NP-30 Mode d'emploi

Yamaha

Yamaha Portatone PSR-38 owner's guide

Yamaha

Yamaha PortaTone PSR-40 owner's guide

Behringer

Behringer MOTÖR 61 user manual

Yamaha

Yamaha PortaTone PSR-62 owner's guide

Yamaha

Yamaha PS-20 owner's manual