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01. Module Overviews

matthewfriedrichs edited this page Apr 4, 2018 · 7 revisions

Hello and thank you for purchasing Hot Bunny! Hot Bunny is a collection of three modules for VCV Rack. This manual will walk you through how to use each module by example, so you will need to download the example patches to get the most from this manual.

Before proceeding, please download the example patches! If you have the latest version of Hot Bunny from the VCV Plugin Manager, get HotBunnyExamples051.zip! https://github.com/matthewfriedrichs/HotBunnyManual

What Is Hot Bunny?

Now let's start with: Example 01 What is Hot Bunny?

Hot Bunny is a very CPU efficient module that produces four uncorrelated random functions. As you can see in the patch, there are four scope modules that show the output of the functions. The four functions are as follows: sample and hold, smooth random, random gates, and random slopes. Each random function is equally weighted, and they all have a range of 0V to 10V.

Now let's learn how to read the front panel markings. The front panel is laid out in such a way that it is a self-documenting flow chart. A patch point surrounded by black is an output. A patch point surround by light gray is an input. A knob surround by light gray affects the input it is connected to. A knob that is connected to an output via a black line directly affects that output. A knob that is connected to an input via a light gray line is directly affected by that input. This means that the top knob attenuates the input, and that result is then added to the knob beneath it.

  • HINT
    • The above holds true for every single module in this set. Once you learn how the flow works, you can apply it to all of the modules!

With that out of the way, we can now move the knobs on the module! The big knob on Hot Bunny simply changes the rate of the random functions. This rate can be changed by the input. Turn up the attenuator on the input, and you will now see that all four random functions will speed up and slow down with the LFO.

The rate knob sets an internal voltage from 0V to 10V, and that decides the random rate. We will now set the LFO to sweep the full range of the random rates. First, set the UNI/BI switch on the LFO to UNI. This sets the LFO to sweep from 0V to 10V. Now set the rate knob on Hot Bunny to 0V. Finally, set the input attenuator all the way to 1V. The LFO is now changing the rate without any outside influence. In most cases, this is not particularly useful.

So let's make it useful! The attenuator basically selects a range you want to modulate the parameter by Set it to about 9 O'clock and then right click the rate knob to set it back to its default value. You should now see that all four random functions now have subtle fluctuations every now and then. A very useful trick is to use a square wave to modulate the rate like this.

  • Before moving on...
    • Hot Bunny is random by nature. It is not meant to be synchronized or tamed by clocks. It is as random as it can get! However, the next module, March Hare, is built to be synchronized to an external clock!

What Is March Hare?

Let's move on to: Example 02 What is March Hare?

March Hare is my personal favorite module of the bunch. It combines the random functions of Hot Bunny, a clock with four divisions, and a wavetable LFO into the deepest random module that is currently available for VCV Rack.

First and foremost, the clock on the left of the module is not normalized to either the synced random or the synced LFO. A clock will need to be connected to the clock inputs on both of them to get them synchronized to the beat. The clock has four outputs. The top output is the master clock rate, and each output below it divides that master rate by two. This means that the bottom output is 8 times slower than the top output.

Now let's discuss how the clock is used in this patch. The top clock output is connected to the synced random, and the clock output below that is connected to the synced LFO. This means that for every cycle of the LFO, there will be two randomly generated voltages from each of the randoms. The bottom clock output is connected to the clock input of the sequential switch. The sequential switch is switching between the four random outputs. For every 8 cycles of the synced random, the sequential switch will change the random function. As you can see, there is already quite a bit of rhythmic mixing in this very basic patch.

Now let's talk about the most exciting part of the module, the wavetable LFO. The LFO has 64 shapes that can be smoothly faded between, and they increase in complexity and randomness from left to right. Sweep the large shape knob for the synced LFO to see all of the different shapes.

  • HINT
    • You can CTRL + click and drag to morph though the shapes in a more controlled manner.

Set the shape knob back to 0V. Now turn the shape input attenuator all the way up to 1V. The triangle LFO will now sweep through all of the possible shapes equally. Notice how the output now looks like a set of white noise; this is not by accident. The range of the shape modulation essentially controls how random the output is. Set the shape input attenuator to around 8 O'Clock. Now you will see a randomized set of the typical synthesizer waves. Let's synchronize these random changes!

Take the second from the top clock output and run it to the synced random clock in. Run the sharp output of the synced random to the shape CV input, and now you will get a new random waveshape every single cycle! Now start to slowly sweep the shape knob. Notice how each set of waves seem to match each other? This is very useful, as a set of "random" and similar waves can then be controlled in time using the synced random to generate a truly random set that will not repeat! Now would be a good time to switch your CV input from the sharp output to the smooth output. Now a completely random data set will be generated in time to the clock. You can even get another set by setting the clock in on the synced random to a lower output on the clock. This will guarantee that one half of the wave is made up of entirely different data.

  • So what exactly does all of that mean?
    • With clever application of the wavesahpe knob and the range of modulation, many colors of noise and random modulation are possible with March Hare that simply are not possible with any other module.

Before we move on to Carrot Patch, I would like to tempt you with the knowledge that March Hare can run at audio rates by using an oscillator as the clock input. Simply run the output through a high pass filter or shift it down by 5V to get it acting as a normal oscillator.

  • Take the time to experiment!
    • Take the patch idea above and make it a reality! It is covered in example 09, but why wait for a good thing?

What Is Carrot Patch?

Let's move on to: Example 03 What is Carrot Patch?

Carrot Patch is the rest of the Westcoast random generator magic. It is made up of 4 very basic sections, and it is best to just cover them one at a time. After the sections are covered, try pulling the patch apart to understand how it works!

The first section is the quantizer. It takes in any voltage and quantizes it to the range that is described above the output. The top output takes 2 and raises it to the power of N. N is any integer from 1 to 24. This gives the top quantizer a range of 2 steps to 16777216 steps. This is great for acting as a bit reducer. The bottom out put has considerably less range as it can only output 2 to 25 discreet voltages! This is great for acting as a non standard quatizer for musical scales. If you set N to 11, and set the range of the output from 0V to 1V, you will get a perfect octave of semitones! You can also set N to 23, and set the range of the output from 0V to 2V to get two octaves of semi tones. In most cases, a dedicated 12 tone quantizer will be faster to use. However, there are many potential applications for experemental generative music.

The two jacks below the quantizer will take any input and subtract 5V. This means that a typical modulation output of 0V to 10V can become -5V to 5V.

The next section over is the probability shifter. It takes in any modulation from 0V to 10V and will shift it from one end of the spectrum to the other. Watch the second scope over to see how the probability of the input is shifted over time as the probability is swept by a sine wave modulation. The blue line is the output and the purple line is the input.

The two jacks below the probability shifter will take any input and subtract 5V. This means that a typical modulation output of 0V to 10V can become -5V to 5V.

  • History Lesson
  • The module that inspired this set could not actually process external voltage in its quantized and probability shifting sets of data! They were just that, fixed sets of repeating data that could be modified. You can recreate this by using the wavetable LFO in March Hare.

The next section over is a sample and hold. The clock input has two flip flops in under it. These flip flops can be used to chain modulation sources or be used to control mixers for mixing the bottom three outputs. The input for the sample and hold circuit has three shifted outputs. Every time a new clock is received, the input will propagate further down the chain. To see the propagation in action, just unplug the input lead then plug it back in after a short while.

The last section has a slew. The slew can be used to smooth the output of the sample and hold. It can also be used as a low pass filter and VCA with a bit of creativity. However, it is mostly meant for smoothing out input. Try it with the random gates!

Below the slew is a basic sine wave LFO. It is useful for feeding the SNH as well as the other circuits on Carrot Patch.

What Is Splitting Hares?

Now let's jump to: Example 10 What is Splitting Hares?

Splitting Hares is designed to add further transformation and waveshaping to any source of modulation. It can take in any two voltage sources then derive and output 8 correlated voltages. If the input voltage is outside of the range of 0V to 10V, the voltage will be wrapped to fit into this range. If 11V is put into the module it will be wrapped back to 1V. If -1V is put into the module, it will be wrapped back to 9V. While this will not affect most modulation sources, a majority of audio rate oscillators will need to have 5V added to them in order to avoid any unintentional wrapping artifacts.

The basic rising saw LFO is being run into the upper left Splitting Hares, and the output is displayed on the upper left scope in blue. The normal saw LFO is displayed in purple. We will now discuss the four parameters and the way they transform the LFO.

SPLICE simply crossfades between the two inputs. In this patch, it corssfades between a rising saw and a sine wave. You should notice some voltage wrapping as you sweep the SPLICE knob. This wrapping allows for non standard waves to be quickly built with basic crossfading. MUTATE will amplify the input voltage after it has been mixed with SPLICE. As we have already discussed, this amplification will cause the voltage to wrap. If you turn up MUTATE on the basic saw input, you will notice that it essentially multiplies the number of saws generated. FORM is perhaps the most useful parameter for making a wide range of modulation shapes easily. It can turn a saw wave smoothly into a triangle wave and then into a falling saw wave. You can even use FORM to smooth out the sudden jumps caused by MUTATE. Last we have the SHIFT knob which lets you vertically shift the voltages of the 8 outputs. On a basic saw wave, this acts as a phase shifter, but on more complex waves will will introduce sudden jumps at various points. Now is a good time to mention that the 8 outputs are already offset by various voltages, and SHIFT will allow you to offset any output without having to re-patch cables.

  • Before moving on...
    • While the above focuses on a basic saw wave input, don't forget to try experimenting with the sine wave input too! For example, you can use FORM to fully rectify the curves of the sinewave. This is a great starting point for making a bouncing ball simulation.

Now we will look using Splitting Hares with a typical ADSR envelope. Using an envelope as an LFO is a great way to get new modulation textures, but the shape of the modulation and the rate of the modulation are directly linked together. This can make experimenting with new envelope modulation shapes a bit tricky when you want to preserve the timing. This is where Splitting Hares is useful as it only changes the input voltage, and not the time of the modulation. Once again FORM is very useful here as sweeping it will introduce no wrapping to your modulation as well as smooth out any sudden jumps. It can even be used as an envelope inverter in a most basic use case. The other useful parameter is SHIFT. This will let you shift and wrap the envelope without adding any extra rising and falling segments. By using multiple outputs, it is possible to build rhythmically correlated modulation sources from any syncable envelope.

The last small example demonstrates how to take a sequence and generate 8 correlated outputs. You may have noticed that you can set the speed of the sequence by changing the MUTATE parameter on the first Splitting Hares that we looked at. The scope displays two different outputs of the sequence after it has been processed through Splitting Hares. You can take these two related sequences, attenuate them and process them though a quantizer to generate musically useful and related harmonies. I would even recommend using a particular random sequence generator with this technique.

While using Splitting Hares as an audio rate wavefolder is covered later in the manual, it is geared towards CV mangling. While the four operations that make up the core of Splitting Hares are very basic, the way they affect various sources varies wildly. Experimentation will be key to get the most out of Splitting Hares, but when you find yourself using a modulation source that you wish had more options, adding a Splitting Hares to your signal chain will be sure to help you discover more uses for some of your favorite modules.

That wraps up the basics of each module. In the next page of the wiki, we will explore basic rhythmic and musical uses for these random modules.

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