The author of Instructables under the nickname collected the proposed active column do it yourself according to a quite ordinary scheme, but placed it in an unusual case - an empty shell from a coconut. Let's see how he worked on this homemade.
At the flea market, the master acquires a broken radio in order to extract a dynamic head and several capacitors from it, and set aside the rest for future projects.
He also takes quite a bit of bamboo to make a handle for a variable resistor.
Acquires a coconut, places it on a jar of coffee, draws a cut line:
Washes a nut, finds the softest among three holes on it, pierces, pours out milk and drinks. Sawing a nut:
Slowly, little by little, he picks out the flesh from the nut with a knife, preventing the knife from slipping off, which can be dangerous. Eats the flesh. The housing is ready.
Apply a little superglue to the end of the bamboo stem, cut off, put on the sawn off piece on the shaft of a variable resistor, fill it with epoxy resin, wait for hardening, remove it. The pen is also ready.
The amplifier circuit takes a standard capacitor between pins 1 and 8 of the LM386 microcircuit. It increases the gain from 20 to 200 and at the same time provides distortions inherent in the guitar amplifier. The master just plans to use the speaker mainly as a guitar combo.
Having decided on the scheme, the master collects the column. The board and everything else turned out to be the easiest way to stick to the shell. The handle to the shaft of the variable resistor is also. In order to make it convenient to change the “Crona” or to remove a battery of a similar format for charging, a magnet sticks - most of these batteries have a tin case. Magnet and battery are not shown.
The column is ready, the master prefers not to talk about how to connect the halves of the shell to each other. Here you can also use magnets and tin strips.
As a possible improvement to the device, the master suggests connecting a capacitor that increases the gain through a switch. You can choose between combo mode and regular portable speaker.But it is better to take the toggle switch in three positions and two directions. When the toggle switch is in the middle position, the column will be turned off, in one side it will be turned on in the gain mode 20 times, in the other in the gain mode 200 times.