Sunday, February 1, 2009

“Why do the 130-in-1 Electronics Kit audio circuits need an audio transformer?”

I'm going through the sound effect circuits in the Maxitronix 130 in 1 Electronics kit and building some on actual circuit boards, but I'm curious about why these circuits all require an audio transformer before plugging into the speaker?

If you compare them to similar sound effect circuits, like the "atari punk console" and kits sold by radio shack, dick smith electronics, and jaycar.co.nz , many of them plug right into speakers or an amp, without a transformer, which seems preferable. Any way to convert the kit circuits into transformerless ones?

A good side question is why the center connection on the three-prong side is used, usually by what looks like the ground/negative line of the circuit.

Open question, anyone can answer, anyone have some info?