Let's Make a Synth

There was a post a while back on how it would be possible to have the 4k emulate a synth. I had done something similar on my XL years ago, but it was very basic without the modulation possibilities of a real sampler. On the 2k you can assign up to 3 samples to an auto chromatic program, have velocity modulation, and use the basic AD amp and filter envelopes, but that’s about it and no live knob tweaking. I've always wanted to try this, but didn't have a real sampler back then. I picked up a Z4 a little bit ago, and this was the first thing I did. I actually have little use for it since I always sequence synths via MIDI... but wanted to learn how so that I would be able to do to samples what I know how to do with synths. The nice thing is that you can sequence notes from a kit like this when you just want to use one box, and then change the routing to MIDI later. This was the post from 2 years ago:
http://www.mpc-forums.com/viewtopic.php?t=16583

MINIMOOG
I was trying to roughly emulate a minimoog patch since that is where I sampled the waveforms from. I set the program to legato to make it a monosynth... but turn that setting off and you have a 64-voice synth, sweet!

OSCS
There seem to be quite a few ways to go about programming this, so it depends on exactly what you are trying to model and what you want to be able to tweak on the fly. I first sampled raw triangle, saw, square, and pulse waveforms from the Voyager. I sampled at a low frequency (midi C0) and 96/24 to get the best resolution from the sample (easier to loop too). Each waveform was trimmed to a single wave cycle and looped. Unlike complex waveforms, you should not need to multisample on basic waveshapes. However, I noticed that the sampler seems to have a range on how far it will pitch the sample. It appears it will only pitch samples 3 octaves (apparently only 2 in 48k mode). I suppose this is a limitation of the engine. I added an extra multisample and keygroup for now, but as it seems, you are probably best getting at least one multisample per octave. Each zone has a set osc waveform. I assigned it 1-tri, 2-saw, 3-square, 4-pulse. So we have a meaty 4 osc minimoog (the real one only gets 3, but has selectable waveforms). You can setup each of the oscs seperately as zones or as keygroups, but I went with zones this time for simplicity and to easily set up knobs for zone osc levels. To fatten up the sound, I slightly detuned the triangle, pulse and square from the saw. Try changing the detune values to get some interesting results. To get more musical results, try detuning a full 5, 7 or 12 (octave). Small detunes actually make it sound like the combined waveform shape has it has an LFO to it, but its just the slightly different frequencies drifting in and out of sync as the waveforms line up.

FILTER
The filter can be set however you like it. I used the LP 4+ to make it squelch a bit (sounds ok, but its no moog filter by any means, sorry). For fun with the filter try different shapes and tweaking the hell out of cutoff and resonance (filter envelope is good for tweaking too).

ENVELOPES
Used basic punchy bass envelopes. Smoothing these out can help turn the synth more into a pad or string sound. These are also good modulations destinations to be assigned by knobs if you want to emulate a knobby synth.

LFO
Set modwheel to LFO1, which modulates pitch and LFO speed. Aftertouch also turns LFO on slightly. LFO2 is very slightly modulating filter cutoff. I wish the LFOs went faster (and sometimes slower), could do a lot more with them that way.

KNOBS
One of the coolest features of the Z is that it allows you to assign tons of the parameters to its Q-link knobs and MIDI CCs. So if you have a 32 knob MIDI controller, you could easily assign all of the knobs and essentially make a full knoby synth out of your sampler. I assigned Q-link knobs 1-4 to the levels of oscs 1-4. This way you can see how each of the waveforms sound by themselves or with each other. For example, try knob 1 up and the others down for a good triangle bass. Careful with the levels as with the way knob modulation works, its easy to overdrive the levels to where you can hear it distort. I set 5 and 6 to filter cutoff and resonance since those are fun on the fly (see note below on this).

LIMITATIONS
You can adjust sample start, but not loop start or end. That is just too bad, you can totally freak the sound out by changing these values. Too see how cool this could have been, try playing one of the samples in the sample edit page while you change the start or end loop setting. A setting like that being tweakable or modulated would have really made it crazy. There are a lot of other synth techniques that aren’t possible such as sync, FM, etc. Although MIDI knobs are cool if you have an interface, they can be a pain to setup. Modulations only allow you to assign them to negative or positive offsets. This means that if you want to make your full knobby synth, you need to have settings set to 0 or 100 to get full range of a parameter. This sucks, because your synth probably wont make any sound from the start in that case until you adjust the knobs accordingly. The other work around is to assign 2 knobs to the parameter (one positive, one negative), but its awkward.

WHAT NEXT?
First off, add reverb, chorus, delay, distortion or other effect... I don't have the card, so I couldn’t set one. There are plenty of modulation slots and work than can be done with them. Set up midi knobs. Change the waveforms (make your own wavetable), filters, envelopes, LFOs, etc. There is lots of tweaking to get completely different sounds like you can do with a synth. In essence, you can start with this basic layout and when you make changes and save the new program, you have a new synth patch.

THE FILES
I'm including a link to a zipped file with a multi, program and samples. I programmed this on a Z4 (I still don't have a 4k), it should work the same though. First try loading the multi to get everything into memory. With the Z4, I was only able to program the first 4 knobs. You need to go to the Q-link page and assign the sliders to EXT 5 and EXT 6 just like the knobs do for EXT 1-4 (otherwise you don’t get filter control). If you resave the multi, the Q-link settings will be saved. The only point of the multi is these preset knob settings. If you don’t need those, the program by itself will do just fine. If you don't understand how any of this works, start reading the manual under "programs" (ak.sys manual helps a lot too). I can't help you with the 4k interface since I don't use one, but the Ak.sys editing is exactly the same and can make things easier to program.

http://mcsmooth.com/junk/z-minimoog.zip
More to follow… next lesson: morphable oscillator waveforms. Enjoy!

Seen at MPC-Forums: < a href="http://www.mpc-forums.com/viewtopic.php?f=2&t=55959">Let's make a Synth - part 2