Kanako Tone
MUA 401
2006　summer

Karaoke

For the project of MUA 401, I built Karaoke, actually vocal reducer. It inputs music from any CD or MD player (or maybe MP3 player), and outputs an amplifier. The user can connect the microphone too, so he/she can sing along songs which he/she likes to sing. The power supply is 9V battery.

Components are below:

• Circuit board
• 2 4k-resisters (Yellow, Purple, Red)
• 12 22k-resisters (Red, Red, Orange)
• 1 560-resister (Green, Blue, Brown)
• 3 1k-resisters (Brown, Black, Red)
• 2 10k-resisters (Brown, Black, Orange)
• 4 47k-resisters (Yellow Purple, Orange)
• 2 0-resisters (black)
• Diode
• 2 capacitors
• Diode (red)
• Switches (for power and vocal reduction)
• 2 IC-sockets
• 2 Transistors
• Electrolytic Capacitors (470uF, 100uF, 9 10uF)
• 2 Dual RCA jacks
• Trimmer
• Audio connector
• IC tips
• Battery case and 3 screws

Only technique to complete this Karaoke kit is soldering. Some of the cupper holes are really close, but most of them are not too close. Thus, this kit is easy to build all by themselves.

Final appearance is below:

On the left white jack, inputs (CD, MD or MP3 player) can be connected. The right white jack is for the output. Black box on the right side is a battery box. The switch next to red light is power switch. When this switch is turned on, the red light is also turned on. The switch at middle bottom is for voice reducer. The red bar next to voice reducer switch is for changing volume of microphone. The leftmost black one is microphone jack.

When I completed this kit finally, the input line, microphone, and output line worked well. However, when the vocal is reduced with turning on the switch, the output has a problem. The left output did not reduce the vocal. Although this problem seemed serious, it was negligible when I connected the output line to only the right jack. Thus, overall this project was successful!

Other photos: