Irregular Timing With STG Soundlabs Voltage Mini-Store
In my Synthesizers.com modular system, I use STG Soundlabs’ time modules for my sequencing. I’m pretty sure that I’m abusing them somewhat, and I can’t lay a finger on why precisely I like them, although I think it’s mostly the flexibility. I like that I can build up a sequencing tool with exactly the functionality I want when I want it.
However, many of the big integrated sequencers have an option for “third row timing” — that is to say, you have, say, three rows of eight knobs which you would typically use to send voltages, either as three separate sets of voltages (say to play a sequence of three-note chords, or to control a pitch, an amplitude and a filter cutoff for each of eight notes in a sequence) or as a series of 24 voltages, and you can take the third row, or the last eight, and in the former mode you can have that row control the timing with which the sequencer moves, moving it forward with more or less speed depending on where that knob is set.
I had a need to do this the other day, and discovered that it’s exceedingly simple to do. In fact, my example patch here has more to it than you really even need:
Irregular Sequence Timing with STG VMS Patch
What’s happening here is very simple. You’re using the manual shift inputs on your two STG Soundlabs Voltage Mini-Stores to advance the sequence, both driven by a pulse wave coming from an oscillator. I’m using a Q106 in the diagram here, so I’d have it set to the LOW range, but you could use any voltage-controlled LFO that outputs a pulse.
The VMS shown on the left is the one that controls the timing, so you set its knobs to the speed you want that step to progress at. The higher the value of the knob, the faster the speed of the step, the shorter the sequencer waits on that step. That might be counter-intuitive for some, so you could use (a) signal processor(s) to flip that over if you wanted to. Its output gets patched into the Q106′s exponential frequency input. You could use the linear frequency — that might be more intuitive for tracking a knob, it it also alters the available range. The frequency knob on the oscillator is used to set the base tempo that you’re working with, in a sense.
The really optional thing I have going on here is that between the VMS and the Q106 I put a quantizer. I’m using the Synthesizers.com Q171 Quantizer Bank in this diagram. The reason for this is that by and large you want to choose from a set of timings rather than having the timing of each step be completely fluid. If you set two knobs to about the same value you generally want the sequencer to pause for exactly the same time on that step. I use a quantizer to do that, even though I suppose you’d need to use the aid module and restrict the available choices to get exactly musically useful fractions. It works well enough for me just putting it through raw as shown.
The pulse output of the Q106 needs to go to the shift input of both VMS modules, of course, because you want to move them both from step to step in lockstep. You could use a multiple for this (which is actually what I do) or just a Y-splitter as shown. If you have them hooked up to a shift manager, it wouldn’t hurt to also plug the step 1 trigger of one to the reset of the other to keep them in sync.
The output of the VMS shown on the right goes to control whatever you want to control — the pitch of a sequence, for example. You could send the Q106′s pulse to more than two shift managers to control several parameters at once. After the first VMS, all others would be “output” ones — used to control parameters. If you use a Q962 to string together 2-3 VMS modules into a 16-24 step sequence, you can do that, although you’d need an equal number of steps of timing control as steps of parameter control (although again you could control multiple parameters with no additional timing modules needed). And you’d need a Q962 for each set. So for 24 steps of custom-timed sequencing of three parameters, you’d wind up needing one Q172, one Q106, 2 Multiples, 12 Voltage Mini-Stores and four Q962s, which, unless you already have them, strikes me as a lot more costly than just doing it all over MIDI -> CV in some fashion. But perhaps more fun, too.