I created the original Learning Modular Synthesis course for those who were complete beginners to the world of modular synthesis. The next question became: How do I help users reach the next level? The answer is the Eurorack Expansion Project. The idea is you have a nice core system, and want to know how to intelligently expand it – particularly if you interested in a specific technique or are after a certain sound. I’m tackling this in two parts: an online course, and a weekly series – including a dedicated Patreon page for the hard-core users out there.
One of the potential challenges of using a modular synth is keeping multiple VCOs in tune with each other as well as external instruments as you play up and down a scale. Most VCOs have trim controls to improve their tracking, but they can occasionally be frustrating to use: They may require you to remove the module from the case to access them, or the manufacturer might have not have used high-precision multi-turn potentiometers for the trimming controls. Therefore, I’ve added several AJH Synth V-Scale Variable Precision Buffers to my modular cases, and have been happier for it. What sets it apart is that 4 of its 5 outputs have high-precision trimmers accessible from the front panel, allowing you to improve the tracking of connected modules like VCOs and resonating filters.
The next big “Learning Modular Synthesis” project is Eurorack Expansion. The idea behind it is that you already have a semi-modular synth or a small modular system, and now you’re wondering what to add next. As the saying goes, you need to walk before you can run. I’ve built up a core set of deceptively boring yet essential modules that will make it easier to interface your core system with the fun new modules you’re dying to try out.
Modern MIDI controller keyboards come with a lot of input options. However, very few MIDI to control voltage + gate (CV/Gate) converters have enough outputs to take advantage of all these performance inputs, plus restrict how you use them to select operating modes. By contrast, the FH-1 comes with eight outputs (expandable to 64), with all of its operating modes available simultaneously. I’ll explain a couple of approaches to harnessing all that power.
A perennial question is “do I really need a buffered multiple to connect to my oscillators?” The correct answer is “it depends” because there’s so many variables with the way different modules were designed. I figured it was time to flesh out those details so it didn’t seem like so much voodoo.
Many semi-modular synths have just one VCO. They usually feature a square wave with pulse width animation, but if you want to use the sawtooth wave instead, the sound can be rather static. A common addition is a second oscillator; an interesting alternative is a “waveform animator.”