Built inside the shell of a Marsona 1200A vintage soothing sound machine is a not so soothing noise device. This was later rebuilt in May of 2012. The updated circuit is based on the Auto-Step Synthesizer. It has controls for LFO speed, frequency, and pulse length, as well as filter and volume.
With a nice loud built-in speaker it requires no additional amplification or equipment to use, although there is a 1/4″ output jack that will cut out the internal speaker and allow it to be used with effects, amps, or recording equipment.
The rebuild also gave it the abilty to run completely untethered on 9volt battery or an optional 9volt center negative DC adapter.