Finally, there's the CV module. This tiny piece of tech lets you add control voltage (CV) and gate/trigger signals from an analog synth to a littleBits system. It brings sounds from not only synthesizers, but keyboards and sequencers (like the Korg Volca line), too -- all of which greatly expand the range of tunes you can mash together as you see fit. Sound familiar? The add-ons were announced last summer, but they're making an official debut now. Once you splurge for the $159 Synth Kit, adding CV and USB I/O modules will cost $35 each, while the MIDI module is priced at $40. Need all three? A Synth Pro Pack is $140, and includes the aforementioned trio and handy mounting boards.