Creating a sequence with sample and hold
What is sample & hold?
Usually, in the world of CV / Gate, when you say "create a pitch sequence," you can think of a "step sequencer" that edits the scale for each step with a slider or knob. Of course, you can edit the scale accurately for each step, and the gate length and glide settings are detailed, and there are also memory functions, which is very convenient.
But in the modular world, you can create such sequences in other ways. One of them"Sample & Hold","Quantizer"It is a method using.Sample & holdTwo inputs, trigger and signalIn response, it is a function that outputs a stepped signal. At the moment when the trigger input is received, the voltage value of another input signal is caught (sample), The CV of that value is maintained from the output until the next trigger signal arrives (Hold) Functions / modules.
In the oscilloscope image above, red is the input signal to sample and hold.The yellow line, which I wrote here, is the trigger input sent to Sample & Hold.The red line is sampled at the timing of the trigger and output as a green line.like thisCreate a staircase voltageIs the job of sample and hold. Since the CV sequencer also creates a stepped voltage, a similar effect can be obtained by sample and hold.There are various sample and hold modules, but in the video, Mutable InstrumentsKinksusing. AlsoRandom moduleHowever, it is basic to sample and hold noise. Qu-bitNano RandIt is recommended that you can use sample & hold and random at the same time.
Now the stepped voltage comes out, but this voltage is not the pitch CV corresponding to the 12 scales.Therefore, I pass through a quantizer to make a scale.The video uses uScale II, but it's convenient because you can see the current scale at a glance with the LED.In addition, Toppobrillo's Quantimator and the new Tiptop's QuantiZer have a built-in sample and hold function.That's the inseparable relationship with Quantizer!
Also, in order to create an input signal to sample & hold, I used the following three modules this time.
-Rebel Technology Stoicheia... A 2-channel gate sequencer for creating sample and hold trigger inputs.Since you can control the rhythm with the knob, you can flexibly control the timing when the pitch changes.Euclidean algorithmSince the rhythm is generated by this mechanism, the point that the sequence that appears is not as "mechanical" as the clock is. In the latter half of the video, I also made a gate sequence to the envelope on the other channel
-4ms Pingable Envelope Generator(PEG)・ ・ ・ Create an input voltage to be sampled and held.This time, the PEG is cycled and used as a clock-synchronized LFO. The Curve and Skew controls allow you to fine-tune the shape of the PEG without changing the speed of the LFO, so modulation it will keep the sequence length unchanged.Subtly changing the phraseYou can let me do it. In the video, I also use the OR output, and I also make an LFO that changes slowly with self patch
-Mutable Instruments Shades... LFO made of PEG is applied with attenuation, inversion, and offset voltage. If you attenuate the sequenceControl the range of moving pitchYes, and by offsetting the pitch of the sequenceOverall high while following the scaleI can do it. (The PEG itself also has Attenuverta, but this time I use Shades' Attenuverter). Also, the 1V / Oct input of the quantizer or oscillator often receives only positive voltage, so if the LFO moves in the plus or minus voltage range, raise the LFO moving range to a positive value with Shades.
Depending on what you use here, the sequence that can be output will vary. Of course, I think you can use a simple clock to make a trigger. This time I used Stoicheia to give a more flexible rhythm. Stoicheia and PEG can make a loop-like sequence by sharing the clock.
The video above shows how to create a pitch sequence using these modules. Unlike a sequencer, you can't make detailed adjustments at each step, but I'm good at creating moving phrases and sequences that span a wide octave range. Improvisation is also high.
Relationship with pronunciation timingUp to this point, I was only thinking about oscillator pitch sequences, but of course in reality you will often use envelopes and VCA as well. Even in the sequencer, you often set the pitch CV and envelope gate as a set. Even in the movie, I have been using envelopes and VCA since around 7'30 ''. So what should I use for the gate that determines the timing of pronunciation?
For example, you can just launch the envelope with the gate sequence used for the sample and hold trigger input.In the video above, when Stoicheia is in "chain mode", one gate sequence triggers both sample and hold and raises the envelope.
You can also launch the envelope with a different gate sequence than the sample and hold trigger.In the video above, Stoicheia, which is not in chain mode, has separate gate sequences that are independent of the left and right channels.At this time, the sounding timing and pitch switching timing are independent, so it is possible to combine rhythm and pitch with a higher degree of freedom.However, in this case, it is important to note that a new sample and hold may occur in the middle of the sound and the pitch may change, such as when the envelope is long decay.In the video above, the decay is short, so it's difficult to understand, but the pitch may change in the middle of the sound.You can think of this as "taste" and it is suitable for legato.
If you don't like the pitch change in the middle of decay, either pronounce at the same timing as sample & hold, or pass the gate sequence for sound timing through a clock divider etc. with Multiple etc. and sample some "thinned" gate sequences. Use it for the & hold trigger input.This way, when a sample and hold occurs, the pronunciation will always start.
TIPSAt first glance, creating a sequence from fine materials is tricky, but there are many advantages. You can create patches that allow you to customize the way you want and interact with other sounds.
You can also glide by passing the pitch signal from the quantizer through the thru limiter. It's also a good idea to mix random numbers in the LFO. Also, if you use the LFO etc. used to create a sequence to modulate other elements of a sound, you can create a patch in which the tone of another sound changes in synchronization with the pitch movement.
It's a very wide patch, so please give it a try!