From the course: Learning Modular Synthesis: Eurorack Expansion

Verbos Scan and Pan: Waveform mixing

(electronic tones) - [Instructor] In this movie, we're going to use the scan capabilities of the Verbos Scan and Pan stereo voltage-controlled mixer. To combine different wave forms from an oscillator, such as the Intellijel Dixie Two Plus, to create a more interesting mix, going off into our filters and the rest of our synthesizer. I've simplified my patch, now, and I'm going to borrow what was my second oscillator, the disting, and instead take the output from the Verbos. I'm going to hook up control voltage to drive my little Dixie up here, and then I'm going to take the output on my semi-modular voice and put it into my output module. Now let's try bringing some inputs across. I've decided I want to use inputs one through four to mix different waveforms from very bassy ones to very bright ones. I want to scan across those waveforms using performance controls, LFOs, envelopes, et cetera. So I'm going to use the subharmonic for input one. So that's going to be the bassiest one. And initially, as you turn the volume control, and turn on the synth, go down in pitch. (low-pitched humming) There we go. (low-pitched humming) Nice, really low pitch here on the subharmonic. Next up, I'm going to choose, say, the sine wave output, which will be one octave up from the subharmonic. (rumbling hum) And you can see on the spectrograph, there is pretty much only a fundamental here. Let's overdrive it a little bit. (humming) Give it a bit more of an edge. For my third waveform, I'm going to choose this sawtooth output. (rumbling tone) And then for the fourth output, I choose the pulse. (atonal humming) A little bit fatter sounding than sawtooth. But to make it even more interesting, I'm going to modulate the pulse width. In this case, I'm going to borrow an LFO from the Moeg Mother-32, this triangle LFO, just controlled by this speed here. Put that into the pulse-width modulation. (phasing hum) Maybe a little less depth. (buzzing hum) That'll be my fourth sound. Go up to middle C here. Now, I can manually control which of these outputs are going to be used by using the pan and scan controls. Pan and scan controls are added into these levels, so I could set up an initial mix and have these modify the mix, or use those controls to control the entire mix. I have the Moeg turned on right now and droned, and I have to hold down a key. Let's play around first with the center. I have a narrow width on my pan and scan, and let's go ahead and actually move this out of the way so you can see the controls a little bit more clearly. So this means, as I scan across I'm going to hit number one, get in between one and two, hit number two, hit in between them, et cetera. Watch the LEDs and listen to what's happening. (buzzing hum) There's output one. Then I'm in between one and two. (humming tone) Now I'm into input two. (humming tone) In between two and three. (buzzing tone) Now I'm on number three. Between that. (harmonic buzzing) And there's number four, our pulse-width modulated sound. And even beyond that, on the scale. And if you want to see these on the Mordax Data while I'm playing with them, let's go ahead and play with that here. Just so you can see the waveforms as I scan through them. (tonal buzzing) Our pulse-width modulation. (tonal buzzing) To the saw. (tonal buzzing) To the sine. (low-pitched buzzing) To the sub-octave. I'm going to go ahead and draw my sync for the data from one of the unused waveforms. From the Dixie, just to help lock things in. Okay, now a potential problem is that my width is so narrow that there's dead bands in between choosing my different inputs. I just need to widen out my width a little bit. So even with this full counterclockwise, let's turn this up until we start to get the first input. (tonal buzzing) There we go, there's a little bit of it there. Let's get a good mix between one and two as we land in between them. (tonal buzzing) And I set the dead spot, so let's go to that dead spot and increase our width a little bit. (tonal buzzing) There's a mixture of the two. (harmonic buzzing) Now, we cross-fade into being just the sine. Cross-fade into, (harmonic buzzing) the sawtooth, and eventually, (harmonic buzzing) the pulse-width modulated square. (tonal buzzing) I think I'll go for a little bit narrower width, if I can. (tonal buzzing) There we go. (tonal buzzing) And I can put that mix underneath voltage control. Turn off the drone for now. And let's choose something such as another one of our LFOs. Now, you notice that the scan and width inputs have their own attenuating control voltage depth control. So I don't need to add in a utility mixer for my LFO. I can do the attenuation right here at the module. So let's go ahead and choose, ah, choose the triangle for now. Put into the scan input, hold a note, (tonal buzzing) and increase its modulation depth. (shifting tones) Now, this triangle is being added to this knob. This triangle is a bipolar symbol, going negative and positive. This is turned full negative. So let's turn this up to start in the center of our mix. (tonal buzzing) You can see us go kind of in between the mix here. Let's increase the modulation depth a little bit more. (tonal buzzing) A little more depth, maybe bias a little to the left. If we want it to be a smoother transition, we increase the width. (tonal buzzing) Or more abrupt, turn the width down. (shifting tonal humming) Now, that alone has some rhythmic possibilities and you could drive it, say, from a channel from your sequencer, you could do the trick we did in the previous movie of using a sample and hold to randomly change that on every note. But you could also use other controls, such as an envelope, to make this mix change dynamically for every note that you play. So let's take that approach. We'll plug this into an envelope output instead. Borrow a copy of my keyboard gate. Use that to trigger the envelope. The envelope is a unipolar signal. It starts at zero, goes up, comes back down again. So I might need to set this initially to the left, to start with a basic sound. I'll start with no modulation depth. (tonal buzzing) Mostly down here in the bass. (tonal buzzing) Then, let's start increasing the envelope's contribution. (tonal buzzing) See, we're shooting across LEDs here. (tonal buzzing) Give it a slower decay. (tonal buzzing) (rumbling hum) (playing notes) So now, each note has this articulation where it breathes through these different waveforms. (tonal buzzing) To create a more interesting sound. (tonal buzzing) We can even make it swell. (swelling tonal buzzing) And that's with no filter contribution. That's very fun, if we have a nice, slow filter sweep on this. (rumbling hum) This closed out a little bit lower. (rumbling hum) (buzzing notes) And we can go for faster envelopes if we want to. (tonal buzzing) Maybe we'll even set this little arpeggio and have fun with the different times to create some syncopation here. (electronic scale playing) Maybe bias a little more to the left, or even emphasize this bass sound. (electronic scale playing) So don't think of voltage controlled mixers as something that you put strictly at the end of your patch. They can be really useful in the middle of a patch to dynamically mix different waveforms, different oscillators, different filters, to add a lot more articulation (buzzing tone) to every single note that you play.

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