In the early 90's I had a Yamaha SY22 with a joystick that implemented "Vector Synthesis", or in other words the ability to cross fade between 4 oscillators/PCM sound sources. The SY series was actually developed from Dave Smith's Prophet VS design...another cool contribution from our esteemed Mr Smith! Anyway, while I haven't figured out if true 4 sound source vector synthesis is possible on the P12, crossfading between the 2 layers definitely is and is super easy to implement...not to mention a lot of fun to play with
Not sure if this has been documented before because it's pretty basic so apologies if I missed it, but here's a quick way I found to make the layer crossfade happen. In this example I'll use the mod wheel to control the cross fade, but of course any continuous controller will do. Here's the necessary settings:
Select Stack Button
Layer A:
1: VCA ENV AMT = 0
2: VCA VEL AMT = 0
3: Mod Matrix Slot: SRC = Mod Wheel, DEST = AMP ENV AMT, Amount = 127
Layer B:
1: VCA ENV AMT = 127
2: VCA VEL AMT = 0
3: Mod Matrix Slot: SRC = Mod Wheel, DEST = AMP ENV AMT, Amount = -127
That's it. Simple. Zero position of the controller sounds layer B alone then raising the controller crossfades between them up to the 127 position of the controller sounding layer A alone
I also came up with a way to use 2 CC's to crossfade OSC1<->OSC2 and OSC3<->OSC4...but...it's not TRUE 4 voice vector synthesis because there's no way to sound ONLY 1 of the 4 sound sources rather than 2. Anyway, here's how I implemented that with a couple knobs on my controller set to CC#2 and CC#11.
1: Mod Matrix Slot: SRC = CC#2, DEST = OSC1LVL, Amount = -127
2: OSC1LVL=127
3: Mod Matrix Slot: SRC = CC#2, DEST = OSC2LVL, Amount = 127
4: OSC2LVL=0
5: Mod Matrix Slot: SRC = CC#11, DEST = OSC3LVL, Amount = -127
6: OSC3LVL=127
7: Mod Matrix Slot: SRC = CC#11, DEST = OSC4LVL, Amount = 127
8: OSC4LVL=0
This is cool, but not nearly as interesting, useful and complex as a way to do true 4 source vector synthesis between complete P12 layers rather than just oscillators within 1 layer. Perhaps there's a way using multi mode and layers to crossfade between 2 patches and the 2 layers in each but I haven't gotten that far just yet
Has anyone else experimented with this with success?