This DIY Music Speaker set is an intermediate electronics project that is perfect for practicing soldering skills and learning about electronics. Play music through your speakers, and watch the LED lights you wired in light up!
These instructions assume basic soldering skills, knowledge of how electricity works, and an ability to handle and work with electronic components. This is not a project for beginners due to the scale of the components and the number of steps involved. It must be supervised by an adult.
Head on over to the Learnary to find the Music Speaker Kit.
These instructions assume basic soldering skills, knowledge of how electricity works, and an ability to handle and work with electronic components. This is not a project for beginners due to the scale of the components and the number of steps involved. It must be supervised by an adult.
Head on over to the Learnary to find the Music Speaker Kit.
Tools & Materials
Material List
- Mini-USB to 3.5mm/USB-A cable
- Conductor cable (4x 24 AWG wires)
- 2x 4Ω, 4W speakers
- 1x Printed circuit board 1 (PCB 1)
- 1x B103 10K Ω 3-Pin single linear dial wheel
- 1x KA2284 5-Dot mono LED level meter driver
- 2x 1 uF Ceramic capacitor (marked as 105)
- 1x MD8002A Audio amplifier
- 1x 25V 10uF Electrolytic capacitor
- 1x 25V 470uF Electrolytic capacitor
- 6x Blue LEDs 3mm (1 is spare)
- 1x 1/4w 4.7k Ω Resistor - yellow - purple - black - brown - brown
- 1x 1/4w 1k Ω Resistor - brown - black - black - brown - brown
- 1x 1/4w 10k Ω Resistor - brown - black - black - red - brown
- 2x Jumper wire (black and red)
- 1x B503 50K Ω 5-Pin single linear dial wheel
- 1x B103 10K Ω 3-Pin single linear dial wheel
- 1x Printed circuit board 2 (PCB 2)
- 1x KA2284 5-Dot mono LED level meter driver
- 1x NS8002 Audio amplifier
- 1x Mini-USB socket
- 1x Switch
- 2x 25V 10uF Electrolytic capacitor
- 1x 25V 220uF Electrolytic capacitor
- 5x 1/4w 1k Ω Resistor - brown - black - black - brown - brown
- 1x 1/4w 10k Ω Resistor - brown - black - black - red - brown
- 1x 1/4w 4.7k Ω Resistor - yellow - purple - black - brown - brown
- 4x Jumper wire 2x black and 2x red
- 6x Blue LEDs 3mm (1 is spare)
- 2x 0.22 uF Ceramic capacitor (marked as 224)
- 2x 1 uF Ceramic capacitor (marked as 105)
- 6x Clear plastic speaker box components (slight differences between bags)
- 4x M3x35mm Standoffs
- 2x M3 Nuts
- 10x M3x10mm Screws
- Safety glasses (not pictured)
Contents of Music Speaker Kit.
Small Bag 1
Small Bag 2
Speaker Container Bags 1 & 2
Tool list
- Soldering iron
- Solder (0.8mm recommended)
- Wire cutters
- Needle nose pliers
- Tape
- Solder wick or solder sucker
- Third hand tool (optional)
- Utility or craft knife
- #1 Phillips screwdriver
- Glue
- Open bags only as you are ready to use them.
- Lay the contents on a soft cloth or rubber mat, inside of a tray, to prevent them from rolling away.
- Make sure all the expected contents are included before you begin to build.
- Wear safety goggles and ensure good ventilation while soldering. Wash hands thoroughly with soap and water after handling solder. Solder contains lead.
Tips for managing many small parts:
Soldering Safety
Procedure
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Solder the MD8002A audio amplifier in place. Start with a leg on either corner to stabilize the component, then go on to solder the rest of the legs. Make sure no solder spills over and bridges more than one leg. If you make a mistake, use solder sucker or wick to remove some of the solder and try again.
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Take the 4.7kΩ resistor (marked yellow, purple, black, brown, brown). Straighten its legs with needle-nose pliers, then bend them sharply 90 degrees at the point closest to the resistor. Put the legs through the front side of the PCB on either side of the “R1 4k7” stencil, then bend them flush against the back of the board to secure it in place. Solder the legs onto the board, then cut the legs flush on the back of the board.
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Take the 1kΩ resistor (marked brown, black, black, brown, brown) and repeat the process to install the resistor in the “R3 1k” position.
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Take the 10kΩ resistor (marked brown, black, black, red, brown) and repeat the process to install the resistor in the “R2 10k” position.
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Take the KA2284 5-dot mono LED level meter driver and place it in the “U2” position on the board. The flat side should face up, towards the capacitors, and the bevelled side with writing on it should face down, towards the “D1” through “D5” stencils. As with the dial wheel, these legs don’t need to be bent before soldering. You may trim the legs once the chip is soldered.
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Take one of the smaller 25V 10uF electrolytic capacitors and place it in the “C4 10uF” position on the board. These components have a fixed polarity — the shorter leg with the white stripe on the component represents the negative side. Make sure that this negative leg goes into the pin with the white stripes on the board. As with resistors, bend the legs to secure it in place before soldering. Trim the legs once complete.
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Take one of the blue 3mm LEDs. Without power they will appear clear. Like the electrolytic capacitors, LEDs have a fixed polarity. The longer leg represents the positive side, and the shorter leg represents the negative side. Unlike the capacitors, the markings on the board have a small hash on the positive side. Install the first LED into the “D1” position on the board, with the longer leg inserted into the hashed (right) side of the board.
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Solder the two jumper wires to the centre of the board, in the box with “+” and “-” marked. Red goes to + (“power”) and black goes to - (“ground”). Strip the 24 AWG wires with a wire stripper, and “tin” the conductor by coating it in solder. Bend the jumper wire once it’s through the board just like the legs on a resistor. These jumpers are for the speaker.
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Put the PCB to the side. It is done for now.
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Open Small Bag 2 and arrange the parts neatly to the side.
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Solder the two jumper wires for the power switch. They belong in the upper-right corner of the board, in the stencilled box with two hash marks. It doesn’t matter which wire goes in which hole.
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Take the 4-wire conductor cable. Use a utility knife to score the outer insulation 1⁄2” from one end. Bend the insulation back and forth along the score mark until broken, then pull the insulation off. Inside there are 4 24 AWG wires (red, blue, green, and yellow) and two strings.
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Cut the strings flush to the insulation. Using wire strippers, strip all four wires 1⁄4” and tin the exposed conductors. Solder the wires to the 4 pins on the top of the board — VCC, GND, D1, and D2. It doesn’t matter which wire goes to which pin, since we’ll build it to match when we install the other side of the cable.
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Put the PCB to the side. It is done for now.
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Open either Speaker Container Bag. Remove the paper film protecting both sides of each piece.
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Install the speaker cone assembly to the front of the box using 4 M3x10mm screws and 4 M3x35mm standoffs. The standoffs should be kept somewhat loose, as this will give you some room to work during final assembly.
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To test the speakers, plug the USB-A connector into a computer or USB power adapter. Plug the 3.5mm audio jack into a music device, and ensure the volume coming from the device is at maximum. The controller speaker has two dials — the one furthest from the speaker cone controls the volume of both speakers; the other controls the sensitivity of the LEDs to the volume coming out of each individual speaker. Adjust the volume to taste, and the sensitivity knobs to see the LEDs react to the music in real time.
You’ve made yourself a set of speakers! This was a complicated project, with a lot of small parts. We hope you’ve enjoyed the process and learned lots about soldering along the way.