PSYN-tology 7 [Radical LFO Pitchbends]

OK, OK, so it's been a while since the last installment. I've got a litany of excuses (including "The dog ate my tutorial."), but rather than going into that, let's just say that I've been busy (and easily sidetracked) with my explorations of PSYN. While I touched on many aspects of the LFO in PSYN-tology 6, many deeper aspects are ripe for exploration. We'll visit some of these here, and hope that it opens the door for your own performance enhancements.

Let's load up the Ring Mod Clavinet patch (5th patch in the new PSYN bank) for this exercise, but, for most of this, the patch could be just about any one. It's a cool sound by itself, but we'll add to the performance capabilities with a few simple steps. First, enable LFO 1. Next, it's decision time, depending on your preference and your particular keyboard controller. In the Control section, you have three knobs: (Modulation) Wheel (CC#1), Aftertouch (non-CC MIDI message), and Breath Control (CC#2). These controls are 'hard-wired' to their respective MIDI messages in PSYN.

I encourage those with Aftertouch to turn that knob to full-on for this tutorial, but those without it aren't left out. The Wheel is one of the most commonly implemented devices in MIDI KB controllers, and quite appropriate for controlling the LFOs in PSYN. You may instead want to assign another knob, slider, or X-Y controller in your KB to CC#2 and use the Breath Controller knob. You could even assign a two-state or momentary switch (like a Sustain switch- reassigned from CC#64) to CC#2, and use that to pop in your LFO.

Whatever method you choose, turn the appropriate knob up each time we enable another LFO, and turn the Depth control just above the Control section for each Modulation destination that we use. The two knobs (Destination Depth and either the Wheel, After, or Breath) work in conjunction with each other here, like trim knobs and fader sliders would. You can 'turn down' the effect that your controller has on PSYN with either one, but you may prefer to have your Control knob full-on, and adjust the amount of effect with the Depth Control. This will many times give you the widest range of control from your KB.

Don't confuse the Destination Depth in the Modulation section with the Depth control in the LFO. For the following exercises, we'll leave the LFO Depth at 0.0% at all times. That way, the LFO will not affect anything in PSYN until we command it to with our performance techniques. We've already covered basic vibrato and tremolo situations, so, if you need to, go back to the other tutorials for review.

Let's get down to business. Change the Set mode to SMONO. Let's take advantage of the fact that, in this mode, the LFO resets with each Note On (as it does with the SPOLY mode). Speed goes to around 300 Hz. (grrr!), Dest1 set to Pitch, Depth of Dest1 to full, and Control knob to full. Click the Saw Down waveform. Now turn up the LFO knob in Osc 1 and fade in your Control (WAB - from here on out, I'll call it that for Wheel-Aftertouch-Breath). You get a 'shortwave radio' glide because your now modulating the modulator oscillator in the Osc 1/Osc 2 pair. Turn down the LFO knob in Osc 1, and up in Osc 2. You'll now get a steep pitchbend effect because we're modulating the carrier in this pair. Turn the LFO knob in Osc 1 back up; this'll mellow the pitchbend a bit, as we're sweeping both oscillators by the same amount. Let's leave them both there for the rest of the tutorial.

Notice that this pitch jumps quickly well above your base pitch, then glides downward. Adjust the Sync Offset knob to -100%. This gives a more predictable 'whammy down' sound. Now turn the Sync Offset up to +100%. If you hold a note, you'll see a delay introduced before the downward pitchbend. The opposite settings will hold true with a Saw Up waveform, along with an upward PB. Let's try that now: Saw Up and Sync Offset = +100%.

Let's take a breather here, and clear up any potential confusion. My descriptions are based on a fully deployed 'WAB' setting in conjunction with your KB control fully up, in the case of MOD Wheel or an assigned knob, or maximum pressure with Aftertouch or Breath Control. A huge variety of nuances can be achieved by a subtle shift of settings or any of the 'in-between' 'levels'. Just wanted everyone to be straight on this, in case the description here doesn't quite match what you're hearing.

OK, where were we? LFO 1 = Set=SMONO Sync Offset=+100% Waveform=Saw Up Speed= ~300 Hz.(grrr!) Dest1=Pitch Depth of Dest1=100% Control(WAB) knob=100%. Go ahead and enable LFO 2 with the following settings: SMONO Saw Down Sync Offset= (minus) -100% Speed=.3Hz. (grrr!) Pitch Depth of Dest1=100% and the WAB to full on. Adjust your keyboard's WAB control. What happened to the pitchbend? It's now almost perfectly offset by the opposing directions of the Saw waves, and the opposing Sync Offset as well. Moving either Sync Offset at this point gives you a wild array of pitch bend effects, from next-to-nothing; past combination up & down sweeps, to the pseudo-random result of the two waveforms fighting for dominance. Likewise, a difference in Speeds between the two LFOs will give you a crazy set of options for some pitch modulation, and the best part is that the amount and timing of the effects can be controlled from your keyboard and/or playing technique.

Now leave all the LFO 2 settings the same, except increase the Speed to .7 Hz. (grrr!) and the waveform to Square. The result is not unlike a stylized 'bell tree' effect, with the trilled notes of LFO 2 being swept upward in pitch by the Saw Up wave in LFO 1. Here the Depth of Dest1 has a huge effect: By backing off the 100% setting, you can change the distance between the two trilled notes produced from octave(s) apart to narrower musical intervals to vibrato-like tones at small percentages.

And while the Depth of Dest1 is set to a few percent, click the Random waveform. A few percentage points difference in the Depth now can simulate analog oscillator drift, a spastic pitch bend wheel, or a classic Sample & Hold effect. The Sync Offsets and Speed settings in both LFOs come into play here, as well, adding to an already large variety of pitch sweeps. If you increase the (Random wave) Speed from .7 HZ.(grrr!) to full up, the tones can imply a jazzy atonal riff to 'stutter/glitch' effects, without all the precise editing usually associated with a true glitch, especially if you add a Cutoff1/Reso1 destination at full Depth to another Dest(x) in the same LFO. A switch to Sine or Triangle wave at these speeds and low Depth can give you sounds that you haven't heard since you watched the Cartoon Network. Keep the settings of LFO2 to Sine/Triangle at a low Dest1 Depth.

Go back to LFO 1, and add Cutoff1 to Dest2 and Reso1 to Dest3, at full Depth. We're screwing around with resonances, so keep your monitor/headphones level low. Go to LFO 3 and set it as follows: SMONO Sync Offset=-100% Saw Down Speed=.3 Hz.(grrr!) Dest1=Lev-All Depth of Dest1 and WAB=full on. Now your crazy vibrato fades out, with the level decreasing in LFO 3 and the Cutoff and Resonance increasing in LFO 1, along with the Pitch. Now increase the Sync Offset in LFO 3 (reduce your volume!) and watch those vibrato notes jump out.

For a variation, let's increase the LFO 2 Keys knob to +100% and listen to how the vibrato speed changes according to where on your keyboard that you play. Remember that this Keytracking feature can be applied to any of these Modulation Destinations that we've explored here, and it's also available in a positive and negative direction, both here and in the Filter(s), and as a more limited 'switch' in the oscillators [disconnects your KB Note Ons from the internal oscillator(s)].

We haven't even touched upon PWM, or adding some Delay to one of these radical pitchbends, or how Phase and Polar affects all this; I'll leave that for your 'homework assignment".

Once again, I hope that I've gotten you curious on alternate ways to produce some pitch bends. We're almost using the LFO's as envelopes here, but many of these effects can be produced with even more control in the EG section. And many LFO-type patterns can be produced in the EGs (Set:Repeat) with more precise control over shape. Hmmm ... have I missed anything? I'm sure that I have, but it'll have to wait for the last of the LFO Trilogy to come out. <g>

Edit: Well, I forgot to add this to the discussion: The methods above also leave your actual Pitch Bend wheel available to augment or modify the other settings controlled by your 'WAB' knobs in both PSYN and on your KB. PB can be adjusted to some extreme parameters, like +/- 4 octaves, and the WAB can be more subtle. Or reverse that scenario. Depending on the Bend Mode choice, you can have the PB wheel bend all, only the high note (or low note), or held notes, and with independent upward & downward parameters. Combine this with PB rising from key pressure, or position on the keyboard scale, or timed delay, and you'll never run out of performance techniques. Those of you with a combination Pitch/Mod joystick or a programmable X/Y controller have it all at your fingertip(s) and those with aftertouch have bonus techniques available to your other fingertip(s).

I also didn't touch upon the Tempo Sync options. Obviously, synchronizing each LFO not only to project tempo, but to each other (either exactly, or in multiples/divisions of the tempo), is a great source of wild effects. Think of a ramp wave distorting pitch sync'ed at 1/2 note, 1/4 note, and an eighth note. All are competing for the attention of the base pitch simultaneously, but in a musical & rhythmic fashion. This stuff just boggles the mind with the possibilities ...

Late-breaking News: A lot of these techniques revolve around using the Saw Up & Down waveforms triggered with a Note On (SMONO or SPOLY) as a type of envelope. I've discovered that at slow speed settings [say, 200 Hz. (grrr!)], no matter what the Set Mode., the Sync Offset has an unexpected (to me, anyway) side effect. At any setting other than 0.0% (default-centered), the waveform 'flattens out" at the beginning or the end of a wave cycle.

That is, depending on the Saw Up or Down selection, and whether the Sync Offset knob is set towards -100% or +100%, the expected gradual rise and sharp fall (or gradual fall and sharp rise-Saw Down) characteristic of a sawtooth wave is clipped or held level for a period of time, before the sloping begins. I mention this both to prevent any confusion during experimentation and to explore the avenues opened up by this news.

I'm sure this peculiarity (?) is present at all speeds, but just more noticible at slow speeds. Now I'll have to explore whether the same effect happens with the other wave shapes with the Sync Offset. I suspect there's always going to be more to discover with this synth ...

Well, another edit, and after a quick review of the other wave shapes, here's what I found: Perhaps it shouldn't have surprised me. The Sine and Triangle waveforms exhibit the same 'flattening' as the Saw waveshapes, while the adjusting the Sync Offset with the Square has the aformentioned effect of determining the interval space between two trilled notes (with a Pitch Destination).

To me adjusting the the Sync Offset is akin to adding a DC component to an AC voltage (as the knob's name implies ...doh!). This can be heard clearly by adjustment in the Random wave shape. Any setting but 0.0% skews the formerly random pitch towards more & more occurences of a specific note. It's an octave lower than fingered with the SO=-100%, and an octave higher than fingered with SO=+100%. These settings make the Random wave shape ...well, not so random. I hope someone finds these discoveries useful. I do, but then again, I'm not that normal ...<g>

Ray, this one was my favorite to explore, and I've learned quite a bit myself in the process. It's quite 'out there', so I'd especially appreciate your input and everyone else's opinion on this one as to it's usefulness and practical application to your playing style.