The Vola V-System Sequencer functions much like a game console, allowing the user to insert cartridges based on the kinds of sounds they want to make. Built by Vola Noisy Stuff from Finland, the instrument can be a beat machine or a more traditional sampler depending on which cartridge is being used at the time. Due to its ability to easily add new sounds, the V-System is perhaps the most versatile of the bunch, pulling noises and effects from different children's toys. It doesn't skimp on the traditional synth controls either, as there's a patch bay and two low-frequency oscillators.

What can you do with a $9 Yamaha PSS-140 keyboard from a thrift store? Well, Mike Sisk added a LTC1799 oscillator to control the pitch and speed of the original instrument's sound bank. He then tacked on echo effects from a $5 Barbie karaoke machine and a low-pass filter and a main panel that offers knobs and switches for pitch, effects and voltage. All of that fits inside a wood frame reminiscent of classic synths, including the recently revived Minimoog Model D.

Last, but certainly not least, there's another modified Yamaha PSS-140 from Chicago-based artist Mike Tewz. For this DIY instrument though, the keys and the control panel were separated to make room for a patch bay and additional controls. Tewz also added an LED sequencer for the PSS-140's built-in drum sounds, an additional control panel and an LTC1799 oscillator module for those pitch and speed tweaks. This hacked PSS-140 rests inside a $5 poker chip case -- you know, if he needs to take it on the road to a music festival.