Saturday, August 14, 2010

Circuit Bent Sing-A-Long Barbie Karaoke Tape Recorder

My plans for a productive 3-day weekend devoted solely to art-making were dashed by some charitable person who donated a Barbie Karaoke tape recorder to the local Goodwill. Not too long ago I read about circuit bending one of these on Peter Edwards fantastic Casper Electronics site, and I've been on the lookout for one ever since. After buying a stack of fresh batteries and looking over the bending schematics I started poking around the main circuit board and identified a bunch of bend points, mostly around the echo circuit. The Barbie Karaoke has a cheap "echo" feature that when bent creates strange and wonderful noise which are generated once you turn the tape player on. After finding about 20 different bend points I decided to build a separate panel on which to mount the the various components, similar to what I did with the Caisotone. The Karaoke machine would be attached to the top of the panel with the wiring running through holes drilled in the bottom, then soldered to the various components inside the panel. Each wire attached to a bend point on the circuit board was soldered to one of twenty banana jacks, which can then be connected by lead wires to a series of potentiometers. I also added a pitch adjustment (located towards the back of the panel, on the left) and both an input and output jack - another cool thing about the Barbie Karaoke is it has two input lines (one for an audio source like a CD player, and the other for a microphone) so you can plug other stuff into it, such as other Barbie Karaokes.

Some photos:

Partially wired panel with banana jacks, switches, and potentiometers.
Each pot can be turn on & off with it's own switch.

View of circuit board back in place with bend points all soldered up & wires fed through holes drilled in the bottom of the karaoke. The bundled wires at the top of the photo are all soldered to points on the echo chip.

View of bottom of completed panel.
The Barbie Karaoke is attached to the top of the panel with a single screw.


Finished view with lead wires plugged into various bend points.

I'm really pleased with how this piece turned out. There are a few other mods you can do, such as adding a variable speed controller for the tape player that involves replacing some circuitry - maybe next time. For now I'm happy to experiment with this as-is:

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