A: In many ways these two tabletop-format analog synthesizers are identical, however there is one huge difference: the Mopho is monophonic (thus the name (MOnoPHOnic) while the Tetra has four voices of polyphony. In fact, you could think of the Tetra as being pretty much the equivalent to four Mophos in one box. Each voice in the Tetra can be assigned its own sound for multitimbral operation, and each can be routed to a separate output. A Combo mode allows the four Tetra voices to be layered together to create a “superpatch.” The Tetra also features USB connectivity.
Sonically, there is little difference between the two, so if you are looking for a fat analog synth for leads or basses, the Mopho will work fine. If you need chords or multitimbral/layered operation, then the Tetra is your machine.