In this tutorial, I show you how to add a tap tempo control to your Korg Volca Series or Montribe analog synth, using your Android (or probably other) smart phone (or your computer). The secret lies in Korg's "sync" control, which is a simple audio "click" signal. Basically, you record the click track from the "sync out" jack with your favorite digital recording medium (your computer, a digital recorder, etc.). Then using Audacity (or your favorite audio editor), clip out ONE of the clicks, and save it as a 16bit Mono WAV PCM file. Transfer this file to your phone's "SD card" memory, and load it in with "Drummer's Metronome", a free metronme app for Android and Blackberry, connect the audio out from your phone to the "Sync In" jack of your Korg synth, and tap away! Use the various controls in the Drummers Metronome app to glitch away at the tempo by changing the time signature, eight notes, 16th notes, triplets, and rests. Fun noises are sure to abound!
Other metronome apps may also work, as long as you can load in your own sounds. You might also be able to use a looper (hardware or software) or other sound source to send the click track to the Sync In jack. There is a threshold in volume for the click to be "heard" by the synth, so be sure to turn the volume up all the way on your phone or other sound source!