“LEGO” FENDER TELECASTER GUITAR AMP HACK

LEGO makes some realistic looking kits. One of my favourites is the Fender Telecaster Guitar and Amp, but it would be more fun if these models actually worked. With that in mind, I modified the model Fender amplifier into a working unit with volume control, speaker, input jack, switch and pilot light. I tried to retain the original appearance by clustering the controls on the back panel and replacing the LEGO pilot light on the front panel with a working LED. The result is a tiny portable amp that works with any electric guitar.

Tools/ Materials:

There are lots of Instructables featuring LM386 amplifier modules. Most would work here. I built this one instead as all the parts are supplied, it’s cheap and it comes with a printed circuit board:

- Mini Electronic DIY LM386 Amplifier Module Kit- (Available from Amazon for about $8 CDN)

9V Battery clip

9v battery

hook up wire

SPST on/off switch

1/4” female audio socket

2” Speaker

Panel mount LED

1K ohm resistor

Solder lug

Epoxy glue

All purpose glue

Double sided tape

Tools: Soldering iron, fine electrical solder, needle nose pliers, wire cutters, strippers, Drill with step bit.and bit to fit panel LED

Lay out all the parts from the kit. Discard the included sockets as you will be soldering the power, input and output directly to the board.

Assembly is easy as the circuit board is clearly marked with actual size icons of the parts with proper polarities. Make all solder connections quickly to avoid overheating the components. Snip off the excess wire of each component.

Work in stages: Begin by installing the potentiometer and IC socket. Next install the electrolytic capacitors. Watch the polarities- they are well marked. Install the LED. Short lead is negative. Next, install the disc capacitors, then the resistors. (Be careful, one resistor is different. Watch the values on the board.)

Last step: Solder hook up wire to each of the “SPKR” terminals, to the + and- terminals and to each of the AUDIO terminals.

Plug the LM386 IC into its socket. Match the notches.

Remove the back panels. Remove all the interior parts which resemble electronic components. Remove the red LEGO piece on the control panel. Drill through its location and press the panel mount LED in place feeding the wires into the case. After disassembling, you may need to glue the control panel and lid in place with the all purpose glue. Drill the bottom rear panel to accept the socket, switch and potentiometer.

Install the switch and solder lug, the socket and the amplifier module to the rear panel using the supplied hardware. Solder the -ve wire of the battery clip to the solder lug and the +ve (red) to one side of the switch. Solder the -ve lead of the LED to the solder lug. Solder one lead of the 1K resistor to the +ve LED lead and connect the other to the second side of the switch. Solder the +ve lead of the amp to the second side of the switch and the -ve lead to the solder lug. Solder the audio leads of the amp to the socket. Solder the speaker leads from the amp to the speaker terminals. Connect the battery. Switch on, plug in your guitar and test.

If it all works, mix the epoxy and glue the rear (magnet end) of the speaker to the inside front of the cabinet so the cone points toward the rear. Stick down the battery with double sided tape. Replace the rear panels. You may want to glue the bottom one with all purpose glue to keep it in place while unplugging your guitar jack.