I having problem with Osc Mix in Dune 1.3. Please follow these steps:
1. Open a Dune instance, write any melody and start loop playing
2. Choose init program
3. Set OSC2 in any easy waveform to hear (ie. SEL-->Off = mute, or Square)
4. Open mod matrix and modulate OSC MIX with Const +100 and Voice 2
5. Set Unison to 2.
6. Set modulation line from Voice 2 to none.
7. Disable unison.
Now you will hear weird things, ie. if you choosed "silence" (SEL-->Off) for osc 2 you won't hear nothing (and the Osc mix will be fully towards Osc1!).
Best regards