ELECTRONIC KEYBOARD
(with price)
ML-2
ML-2
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Circuit Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Schematic Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
PCB View and Major Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Exploded View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
IC and Transistor Lead Identification . . . . . . . . . . . . . . . . . . . . . 11
Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
CONTENTS
-- 1 --
General
Number of Keys:
32
Illuminated Keys:
White and Black keys
Polyphonic:
2-note
Preset Tones:
25
Auto-Rhythms:
12
Demonstration Tunes:
10
Lesson Functions:
3 modes; Demo, Any-Key Play, Melody Guide
Built-In Speaker:
8.0 cm dia. 1.0 W Input Rating: 1 pce.
Terminals:
Output Jack [Output Impedance: 100
, Output Voltage: 1.6 V (rms)],
AC Adapter Jack (DC 7.5 V)
Power Source:
DC: 5 AA size dry batteries
Battery life: Approx. 5 hours (SUM-3/R6P)
AC: AC adapter AD-1
Power ON Reminder*:
3 minutes after the last operation
Power Consumption:
1.5 W
Dimensions:
57 x 415 x 208 mm (HWD)
(2-1/4 x 16-3/8 x 8-1/4 inches) (HWD)
Weight:
1.05 kg (2.3 lbs) including batteries
Electrical
Current Drain with 7.5 V DC:
No Sound Output
44 mA
± 20%
Maximum Volume
175 mA
± 20%
with keys B3 and C4 pressed in Flute tone
Volume: Maximum, Rhythm: Rock,
Tempo: Maximum
Speaker Input Level (Vrms with 4
load):
750 mV
± 20%
with key C4 pressed in Flute tone
Volume: Maximum
Output Level (Vrms with 47 k
load):
800 mV
± 20%
with key C4 pressed in Flute tone
Volume: Maximum
Minimum Operating Voltage:
6.2 V
*Power ON Reminder
Power ON reminder is sudden audible and light signals, a short melody at maximum volume and
lighting up the illuminated keyboard for a few seconds.
Power ON reminder functions three minutes after the last operation, and it repeats every three minutes
until turning the switch off or restarting operations.
SPECIFICATIONS
-- 2 --
BLOCK DIAGRAM
Nomenclature of Keys
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
KO0~KO11
KI0~KI7
Illuminated Keyboard
Switches
Oscillator
XL1
Amplifier
AN8053N
IC1
Speaker
CPU
MSM6521-11
LSI1
LEDs
LX0~LX3
LY0~LY7
Power Supply Circuit
T1, D4
VDD 5.6V
AVDD 5.6V
Filter
T2
Output Jack
-- 3 --
Key Matrix
KI0
KI1
KI2
KI3
KI4
KI5
KI6
KI7
KO0
F3
F#3
G3
G#3
A3
A#3
B3
C4
KO1
C#4
D4
D#4
E4
F4
F#4
G4
G#4
KO2
A4
A#4
B4
C5
C#5
D5
D#5
E5
KO3
F5
F#5
G5
G#5
A5
A#5
B5
C6
KO4
Volume
Down
Volume
Up
Light
On/Off
KO5
Tone 1
Rhythm
Stop
Tempo
Down
KO6
Tone 2
Tone 3
Tone 4
Tone 5
Rhythm
Select
Tempo
Up
KO7
Melody
Guide
Any Key
Play
Demo
Play
LY0
LY1
LY2
LY3
LY4
LY5
LY6
LY7
LX0
C6
F5
E5
A4
G#4
C#4
C4
F3
LX1
B5
F#5
D#5
A#4
G4
D4
B3
F#3
LX2
A#5
G5
D5
B4
F#4
D#4
A#3
G3
LX3
A5
G#5
C#5
C5
F4
E4
A3
G#3
Keyboard LED Matrix
CIRCUIT DESCRIPTION