KORG volca mix is a compact, 4 channel analogue mixer designed to go hand in hand with the volca series of gear. You get two mono inputs and one stereo (all mini jacks) along with three DC outputs, making it perfect to sync, power and control up to three volca units. Control-wise you can adjust the gain, volume, mute and hi/low pass filters on each channel as well for effects or just to balance the mix.
The master chain got a few effects as well (like expand mono to stereo and sidechain) and you can process the sound further by hooking up external effect units for each channel using the mini jack send out and aux in.
Check out the KORG volca mix in action here: