tardishead wrote:This is really amazing
Not many self generating patches I’ve heard have any emotional effect but this one definitely does.
Would you mind dumbing it right down for me and explain it in as universal terms as possible. I find eurorack a bit mystifying. I don’t know what Rampage is but I have plenty of VC Slope modules - is like that?
Is it a hard or soft sync at the base of your patch?
Thanks very much. I'll have a go at explaining what's going on.
There are a few components to the patch, but the main ones are a feedback loop that generates the pitch CV, and an Analog shift register.
The pitch part takes the output of an oscillator and processes it to generate a voltage that is in inverse proportion to the pitch. It's also imprecise, and also wraps, so if the input pitch gets too low, the output goes low again and vice versa...
This value is sampled and delayed, then used to generate the next pitch (or a pitch for a different oscillator...) either way it creates a contrary motion so each pitch is related to the last, but also has some chaotic behaviour at some settings due to the imprciseness of the process. It is also fed through a pitch quantiser so the pitches are from a specific scale or chord depending on the setting.
The shift register is a bit like a delay, but it delays the pitch CV rather than the actual audio. It has three outputs, and each one gets the value the previous one had on the last clock tick. The interesting bit is that each one is connected to a different oscillator with a different setting, so the same CV value won't necessarily generate the same note or timbre from the different oscillators. I also delayed each shuffle step of this delay to get a cascade effect - the new notes are sent to the oscillators in sequence rather than all at the same time on the clock tick.
So basically you get pitches that are related inversely to the one before due to the feedback system, and also each oscillator gets a pitch that another oscillator was just using (except the first one of course... and all the notes come from the same chord or scale... So there are multiple temporal and harmonic relationships between them. Our brains like those sorts of things.
The time is also broken up because I modulated the clock driving the whole thing using a division of its own output. This creates a very slow type of shuffle, so the meter of the track swings a bit in an interesting way.
The oscillators are mixed, and then put through the same filter set hot enough to create a little saturation. As they are sines and a triangle, they also create extra 'beat' frequencies. All these frequencies pushed through a saturating filter with some slow frequency modulation gives a really nice (IMO) texture and timbre. It swells and pulses, and sounds kind of natural... Sometimes the frequencies are very high, sometimes very low, and these interact in interesting ways when process through the filter as well.
I also grabbed another output of one of the filters to create another sound that plays fairly short, then echoes away - and as this is from one of the oscillators in the existing process, it's also part of the same harmonic system.
Finally, just playing with it and tweaking all the parameters until it starts to sound nice.