A few weeks back, we started building two techno-oriented systems – one small and one large – and chose our synth and percussion voices. Today, we’ll be continuing the builds with all the sequencing and modulation we’ll need to make our patches move.
Clocking
Before we pick out any sequencers, we need a clock generator. A clock generator is a utilitarian and incredibly useful module that will set the tempo of our patches, advance our sequencers, and keep them in phase (if we want it to). Some sequencers have clocks built in, but the ones we’ll be using today require an external clock.
If you decide to go a different direction with your case, you’ll probably find that a clock module is a useful tool to have: even if you have sequencers with built-in clock generation, other things like modulators and effects sometimes need clock signals, too, and if you have multiple sequencers you’ll want them to be in sync with each other. Clock modules also allow you to stop and start your entire patch easily.
Today, we’ll be using Horologic Solum as our clock: this is a simple clock generator with four divided outs. In our small case these division outputs will be particularly useful: in a pinch, we can use them to generate some of the percussive rhythms we’ll need (a simple quarter-note pulse is great for driving a kick drum), freeing up space for other modules.
Rhythms
To make our drum modules groove, we’ll need some trigger sequencing. There are lots of options for generating rhythms in Eurorack: step sequencers, algorithmic generators, logic and clock signals… There are a lot of choices, which means you can probably find something that suits your fancy with a little digging.
In our larger system, I went the algorithmic route with Numeric Repetitor. This is a generator that creates rhythms based on prime numbers, and its simple interface makes it a breeze to use in a jam: just tweak a few parameters and you’re off. It has four rhythm outputs so it can drive our whole percussion section, too.
In our smaller case, some of our simple percussion sequencing can be done with Horologic Solum – but to add a bit more diversity, I included Bin Seq, as well. Bin Seq is a straightforward eight-step sequencer that’s got simple on/off switches for each step. It’s easy to use, and fun to play live in a patch, adding a nice performative component to our compact case.
Pitch
For our melodic voices, we’ll need some pitch CV as well as rhythmic triggers. Pitch sequencing can be done with pre-programmed step sequencers, or with generative sequencers that create melodies on the fly. In our big system, I included options for both for more flexibility.
Mimetic Digitalis is a four-channel CV sequencer that can quantize its outputs if you feel like writing out a particular melody. It’s also great for modulation, if you’re not using all (or any) of its outputs for pitch. It has a number of clock and CV inputs that can be used to advance it in a variety of different ways, so it’s a fun sequencer to patch creatively, too. I included it as the main pitch sequencer in our compact system, and a pitch and/or modulation sequencer option in our large case.
If you’d rather have a module that can help you create music, generative sequencers like Gamut Repetitor are a great option. Send in a clock and Gamut Repetitor will generate note patterns automatically. When you hear something you like, you can loop a number of previous steps with options for patterns between 1 and 32 steps. It also has a built-in quantizer with various scale settings and controls for range, root note, and distribution so you can control the tone of the sequences that are generated.
Modulation
Modulation is the heart and soul of modular synths: if you need to spice up a sequence, modulation CV can help keep things varied and interesting. In our small system, Mimetic Digitalis plays double duty, helping to modulate our voices with stepped CV.
In our large system, in addition to Mimetic Digitalis, we’ve included a couple of other modulators. Clep Diaz is a random stepped or smooth CV generator that’s a wonderful tool for creating CV based on incoming clock signals. Last month, we chatted about a few ways we patch with Clep Diaz: it can do anything from subtle changes over a long period to big, stepped shifts. They’re great in pairs, so I’ve included two in our large system.
Along with CV generators, performance-oriented utilities can be a helpful addition in a performance case. Lapsus Os is a set of four faders that can offset or attenuate an external CV signal (like the ones generated by Clep Diaz or Mimetic Digitalis), or create offsets by themselves. I like to use it to bring modulation in and out of a patch on the fly, or to increase and decrease the decay time of my percussion voices with a single control.
A note on MIDI
If you’re using a laptop or another MIDI sequencer like an Elektron box along with your system, MIDI control is a great option to consider for integrating your system with your other gear. A MIDI to CV converter like Univer Inter is a great way to do just that: you can turn the MIDI clock from your other equipment into analog signals to drive sequencers in your rack, or you could use it as a MIDI to CV converter to convert MIDI notes into gate and CV signals and do your sequencing outside of the rack.
How’re things looking?
Here’s where our two systems look after today’s additions. Our large system now has Horologic Solum for clocking, Gamut Repetitor for melodic sequencing, Numeric Repetitor for rhythm generation, and Clep Diaz, Lapsus Os, and Mimetic Digitalis for modulation.
Our small system also has Horologic Solum for clocking and Mimetic Digitalis for sequencing and modulation, as well as Bin Seq for some rhythmic options.
We’re getting somewhere! Next time, we’ll look at mixing and effects and finish off our systems.
