As my kids were quite excited with my BuffaloAmp project, i organised a speaker building project for my kids workshop groups.  This project has evolved a bit over time, the current version uses a laser cut tabbed box with 2x 3W 4ohm speakers.


For details on the circuit, see the original larger size. First i downsized it to 2W 8Ω drivers, and left out the DC-DC booster, powering the amp straight from a Lithium cell, nominal voltage 3.7V. At that voltage, the amp would only deliver 1W per channel, so these smaller speakers can’t get damaged. I used the same Lithium battery charger but did not take out the charge status LEDs; we just made holes in the side of the speaker box to be able to connect the micro USB directly to the charger PCB, and the red/green light is visible through the hole.


original BuffaloAmp plus 4 kids versions

The latest edition (2017) is a laser cut tabbed box with 3W 4Ω speakers as in below picture.


To make this project with kids, i usually split it up in 3 sessions:

  1. understanding the electronic parts and connections
  2. putting the wooden box together
  3. installing the components in the box

schematics of the components, for details see BuffaloAmp post

So this speaker box just needs to plug into a music source, any phone or mp3player with a headphone connection (3.5mm jack). The battery lasts for over 10 hours, and can be recharged with a standard micro USB connector, just like a powerbank.


mounted inside: LED with resistor, switch, jack cable with knot to prevent pulling connections, charger board on the bottom with USB connector through hole, green Lithium cell, amp PCB at back with male/female dupont connections

I prepared the box panels for the kids, including gluing the triangular supports to the side panels. The got 6 panels, and together we drilled the holes for the screws with a cordless hand drill. The holes for the speakers were a bit more challenging, i borrowed a circular drill bit from a friend. Then we put the components into place with hot glue.








And the kids were very creative to paint their boxes!



The most recent batch of box panels were made with a laser cutter, and i also made a simplified version with 3x AAA batteries (non-rechargeable).




I explain the schematics with a puzzle as below, and then i ask the kids to draw their own version on a card to stick on the back of the speaker, as above.


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