Orca's Heart

Collection One

Orca's Heart

Orca's Heart is a quad algorithmic polyrhythmic sequence generator based on Orca, the alternative firmware for the monome white whale module.

Might sound complicated but what it basically does is generate up to 4 sequences (CV/gate), 4 modulation CVs and 4 gates. It uses the same principle as the original Orca - combining 4 clocks running on different divisions of the main clock to generate notes. This can result in surprisingly complex and expressive sequences, especially when you change various underlying parameters.

The original Orca allowed direct control of pretty much every parameter. Orca's Heart takes that (hence the name) but instead of individual controls it provides inputs and knobs that affect multiple parameters, selected for maximum expressiveness. It also takes advantage of being self patched - this is where most fun is - more on this below.

Getting Started

First off, you don't need to use 4 voices with it. It'll work just fine with a single sound source. Add it to your patch, then patch Note CV 1 output to 1 V/Oct input of your oscillator and Note Gate 1 output to your envelope gate input (assuming you have a typical patch of oscillator / VCA / envelope). Tweak the knobs and listen. That's it!

If you're getting atonal results or if the pitch range seems big - you are probably using Mod CVs instead of Notes CVs - pitch CVs is the group on the right. The left group has a 0..10V range and is more suitable for modulation.

If you're not getting something you like, check out the Tips & Tricks section below!

Scales

Orca's heart will only use currently enabled notes. There are two scales available, A and B, with the active one indicated by LEDs. You can switch between them at any point, and there is a corresponding input that will switch between scales upon receiving a trigger. A fun thing to do is to use the Reset output to switch between scales!

To the right from the scales are buttons/inputs that add an octave, which is another good way to add more movement to a sequence.

Parameters

Let's take a look at what various parameters do:

• Length: this defines how long a sequence is. The range is 1..32 steps.
• Speed: the value is in BPM but since OH operates with clock dividers, the actual sequence's speed will be determined by the algorithm.
• Algo X: this parameter affects the algorithm responsible for building sequences. Changing it will have the most effect on the sequence.
• Algo Y: this parameter affects how notes and gates are selected for each output from internal sequences. Changing this will also sound like you're changing the actual sequence but the effect is different from Algo X.

Both Algo X and Algo Y are set up to change gradually as you turn the knobs, but due to OH's nature sometimes you can get drastic changes even changing them slightly. Same values will always produce same results though, so if you hear something you like, write down the numbers or save it as a preset (but remember - other parameters affect the sequence too).

• Shift: this parameter will affect how scale notes are selected. It doesn't change the actual sequence, but it can sound like it does and can produce very musical results.
• Space: if you increase it it will introduce gaps in the sequence - this is a good way to give it a room to breath, especially for slow ambient patches. It's also a good way to make a sequence less static, especially if you modulate it with an LFO or one of OH's own outputs.
• Transpose: transposes all Note CV outputs by the specified amount. The range is -2V..2V. Please note the corresponding input is also scaled to this range, it's not 1 V/Oct!
• Gate Length: controls gate length for Note Gate outputs.

All parameters have CV inputs - the range is added to the knob range. It expects a 10V range - either -5..+5 or 0..+10. If you use a bipolar source, set the corresponding knob to its middle position to get the full range.

Modulation Outputs

Mod CV outputs are stepped voltages generated using the same algorithm, but using different parameters. They can be used to add variation - patch them into filter cutoff, or delay feedback etc etc. Mod Gate outputs are direct outputs of the clocks at the heart of OH's algorithm.

Clock / Reset

You can use an external clock source - OH will detect when something is connected to the Clock input and will stop its own clock. Reset input can be used to reset the sequence before it reaches the end. OH can also be used as a clock source using its Clock output. Reset output is triggered each time Length is reached.

Modulation: Creating interesting sequences

Now, you played with it and you're bored. Time to self patch! OH was specifically designed to be self patched - this is the key to creating interesting sequences. There are no rules - try everything! Take advantage of the Mod outputs - but don't forget you can use Note outputs for modulation as well. Same with gates, use them as your mod sources too. What's really fun about it - when you self patch OH, you use the sequence to modulate the algo parameters - which changes the sequence itself. Algorithmic feedback!

A good way to experiment is modulating just one parameter at a time. Try plugging a slow LFO into Shift input, for instance. Get a feel of how different parameters affect the sequence. Try attenuating mod sources too, to have more control.

Four Voices

And now that you tried it and made it to here, go ahead and use it with 4 voices. You know you want to! OH was designed to create 4 sequences that compliment each other and combine in interesting ways.

Tips & Tricks

Sequence too busy?

If you're getting a sequence that seems too busy, try one of the following:

• increase Space parameter or plug some modulation into the Space input
• remove some of the notes, or if you're using one scale, copy it to the other scale, remove some notes there, and use one of the gate outputs to switch between scales
• clock it from a trigger sequencer and only have gates on some of the steps

Sequence too random?

It can be tempting to throw a lot of modulation at it (and indeed it loves modulation, especially being self patched) but at some point you might get something that sounds like a random voltage put through a quantizer. Try removing some modulations and see if it sounds better. If you're using external mod sources like an LFO, set it to a slower speed (a slow LFO into Shift input, for instance, can make for really nice variations).

Alternatively, start with no modulations and add them one by one. A good way to experiment with this is to use a patch matrix (such as Strum's Patch Matrix) or even a matrix mixer (such as Bogaudio's Matrix 88). Patch various OH outputs into matrix inputs and patch matrix outputs into OH inputs.