Sparkling gems and new releases from the world of Free and Open Source Software


Article from Issue 205/2017

Graham Morrison looks at VCV Rack, Audible Instruments, TripleA, Neofetch 3.3.0, TripleA, Eolie 0.9, and more!

Modular synth studio

VCV Rack

Before audio synthesizers were neatly packaged into boxes that contained a keyboard and all the components necessary to make a sound, they were modular. This meant you needed to link each component together with patch cables in a way that created the kind of sounds you wanted. Voltages would modulate parameters to produce audio, which could then be routed into different processing modules. After recording or playing the sound, you'd deconstruct the patchwork of interconnections and start again. This is how Delia Derbyshire worked at the BBC Radiophonic Workshop, for example, or how anyone made a sound before Bob Moog came along and changed everything.

Integrated circuits (ICs) eventually pushed these behemoths aside, much as ICs and microprocessors did vacuum tubes. Programmable, neatly packaged synthesizers have now dominated for the last 30 years. But modular synthesizers are coming back, thanks to the combination of a smaller packaging format (called Eurorack), ARM processors, cheap home brew electronics, and a backlash against screens and workstations. Constructing your own sound sources from a mess of patch cables is cool again; sounds are often generative and experimental, with users meeting up to share setups and making the entire scene feel a little like a modular maker community.

The only problem is that this is an expensive hobby. Each module is often constructed by a few individuals and produced in small batches. They need specific power supplies and interfaces to get them talking to your computer. And that's why VCV Rack is one of the most brilliant pieces of audio software I've come across in a while. It's a software emulation of the infrastructure needed to host these modules, connect cables, edit parameters, and save patches. It even includes a batch of modules to get you started. There's a VCO for sound generation, a VCF for filtering sound, and both a VCA and an ADSR envelope generator for changing volume over time. There's also a delay effect, a mixer, an oscilloscope, and a sequencer – a batch of modules that would cost you a small fortune if you happened to be building your first physical modular system.

With VCV Rack you simply right-click the modules into your virtual rack and start connecting outputs to inputs. It sounds just as good as the real thing. But I've left the best feature until last: You can install other modules from external sources, and this seems to be Rack's raison d'être. Rack's author, Andrew Belt, has cleverly taken the open source firmware behind some of the best Eurorack modules available, from Mutable Instruments, Befaco, and Synthesis Technology, and emulated their physical connections in software – from their seven-segment displays to their huge knobs. This means you can run virtual recreations of real hardware running the real firmware for free from a Linux desktop, and it's amazing.

Project Website

1 Presets: Unlike real modular synthesizers, you can save and load presets with VCV Rack. 2 Cable tuning: Both the appearance and elasticity of cables can be adjusted. 3 Eurorack modules: Using the form factor of real modules lends VCV Rack an uncanny feeling of realism. 4 Bundled modules: VCV Rack includes a decent collection of eight modules, such as sound generators, processors, and utilities. 5 Patching: Cables connect control voltages, audio, trigger, and gate impulses, just like real hardware. 6 Oscilloscope: This modules even has a real-time updating input display. 7 Audio interface: Get audio output into your headphones and audio input into your virtual modular. 8 MIDI: Connect external keyboards to the software.

Virtual audio modules

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