Lesson 2: morphable oscillator waveforms
POLYMOOG
I took the same multi and program from before and made some changes. I turned off legato (to make it a polyphonic synth), smoothed the envelopes, brightened the filter and it sounds more like a pad now.
OSCS
In the last program, we had 4 different oscs each with their own volume (one for each zone). This time I set it up more like a traditional synth. There are 2 oscs, but this time, we can select the waveform for each. On a minimoog you can actually morph the osc from tri to saw to square to pulse. I am trying to emulate that using the zone x-fade feature. Basically each of the 4 samples are left in the 4 zones, then they are set up to X-fade in real time. We then set one of the knobs to control "zone select". This is technically not a morphable osc, but cross fading between different ones. This means you don't quite get the same osc shapes in-between zones and hear a thicker sound (but you get the point). It may be possible to get a better fade by using multiple keygroups to span out more samples… kind of like how it was discussed to get 16 samples spanned over velocity, just very complex to program and more tedious sampling.
KEYGROUPS
1: Osc 1 low octaves
2: Osc 1 high octaves
3: Osc 2 low octaves
4: Osc 2 high octaves
Multiple keygroups play an important role in this program since we need to use one for each osc this time. Last time we simply had our 4 oscs in zones (1 keygroup), but this is not possible since we are using the x-fade feature. I copy and pasted the existing keygroups into a second set for our second osc.
Q-LINK
1: Osc 1 shape
2: Osc 1 / Osc 2 fade
3: Osc 2 shape
4: osc 2 pitch offset
This allows us to select the shape of both oscs independently with knob 1 and 3. 2 acts as a cross fade between osc 1 and 2 so you can hear just one of them or a mix of both. 4 allows you to detune the second osc from the first to thicken the sound. I left 5 and 6 on the cuttoff/res. Another cool thing to do would be to create a new keygroup that played the triangle osc at 1 octave below and set a knob/slider to its amplitude; a dedicated sub-bass control.
MODULATION
The Q-link controls above took me forever to figure out, but I learned something very critical. The mod matrix allows you to set parameter amounts, and specifically what keygroup you want to apply this to. By default, it is set to affect All keygroups (and this will do for most cases). The keygroup parameter is NOT in ak.sys! I had always assumed that you pick what keygroup you want to assign the modulation to and that’s it. However, I learned that you could actually make a separate offset for EVERY keygroup including the All parameter. So ak.sys ONLY makes the change on the All parameter, but on your machine you can store many different kgrp settings. This allowed for example, knob 4 to only affect the pitch of keygroups 3 and 4. Even cooler was that on knob 2, I set keygroup 1 and 2 to negative amplitude and positive on 3 and 4. This make a decent crossfade, but it will be a bit quiet in the middle (its too bad you can't set EXP and LOG for modulation amounts). What killed me on this is that you need to make sure All is set to +0. I thought I might need to program out 4 modulations for each, but this completely unexplained feature makes for many possibilities.
THE FILES
Same file from before, just added the polymoog multi and program. The program is more useless on this one without the multi since it relies on the q-link knobs to get an interesting sound. The program is only useful solo if you change the respective controls manually and save them that way. I wish you could have “pages” of Q-link knobs like the Nord G2 (and those LED graphs too, oh yeah).
http://mcsmooth.com/junk/z-minimoog.zip
