The Eurorack format used to be mono only, but a new generation of modules can bring out the stereo field. How can you integrate them into your system?
In 1931, inventor Alan Blumlien was sitting in a local cinema when he was struck by the idea of applying stereophonic sound to motion pictures. He was awarded a patent in 1933 for a unique disc-cutting process and the very first stereo phonograph records were produced that same year. However, it would take the technology—and a skeptical public—another two and a half decades for stereo sound to achieve widespread acceptance and for the format to become standard in most homes and venues.
This was understandable - the cost of transitioning to stereo was considerable, and media was still being widely produced monophonically. For stereophonic sound to become commonplace, it would take a serious effort on the part of both industry leaders and the consumer. Stereo technologies had to become cheaper, more accessible, and the public needed to understand the benefits they would provide.
It seems as if a similar situation is playing out now within the modular synthesizer community.
A bit more recently in 1995, Dieter Döpfer introduced the Eurorack synthesizer format to the world and 25-plus years later, we’re seeing an explosion of stereo tools within the modular realm - almost now becoming expected of new releases. Manufacturers and synth-heads alike are delighting in the widespread implementation of stereophonic modules, and they’re becoming more accessible and easy to use than ever before.
Much like the phonograph record, it’s taken a bit of time for technology to shift and for us as a whole to embrace the power of stereo sound in our systems. Before we had this modern plethora of modular options, one would need to own pairs of everything if they wanted to achieve true stereo. Now, from our oscillators to our effects chains, it seems like everything is ready for stereo processing.
When I first began my own modular journey ten years ago, I remember stereo options being limited to a handful of processors—the scene I knew was predominantly mono, and I was cool with that. Working with mono signals never impeded the joy of patching a modular system, however, the addition of a rich stereo field has added a new layer of sonic complexity and experimentation that truly makes me enjoy the instrument even more.
With an ever-growing number of options for customization and self-expression within the Eurorack universe, isolating the right tools to introduce stereo into your system can be daunting. So, let’s take a minute to shine the spotlight on a few notable manufacturers producing stereo products, and a few of their modules that are redefining the way we think about our systems.
This Eurorack juggernaut is at the forefront of the modular stereo movement. With the announcement of their highly anticipated oscillator, the XPO, they now offer a fully stereophonic modular voice. Here are a few noteworthy pieces from our friends in Asheville, NC.
Morphagene. This beloved module remains one of the most popular Eurorack modules of all time and offers users the power of a digital tape machine in 20HP. With stereo sample capture and playback, a unique array of audio parameters, and tons of CV I/O, the Morphagene has solidified itself as a modern classic.
XPO. The latest release from Make Noise is an analog oscillator featuring three unique stereo outputs. The module’s internal pulse-width, wavefolder, and vari-timbre parameters can be modulated on either the left or right side independently. An additional five analog mono outputs, two 1v/o inputs, FM, and sync input round out this powerful voice.
QPAS. Boasting a purely analog signal path, multiple resonant peaks, four sets of stereo outputs, internal VCA, and plenty of CV capabilities, this filter offers a ton of control and timbral flexibility. Pair this with the XPO, Mimeophon and any of their classic dual utility modules for a full stereo experience.
Qu-Bit produces some dazzling stereophonic sound sources and effects modules. Their newest release, Aurora, will have you questioning your concept of what a stereo reverb can be.
Data Bender. This has to be one of the most unique offerings to hit the modular effects world in a long time. Embodying all that is stutter, glitch, and degradation - the Data Bender scratches an itch that you weren’t even sure you had. Its latest firmware update allows you to control the depth of its stereo field and the module’s ample CV inputs allow for intricate modulation possibilities.
Surface. Surface stands out among the saturated offering of physical modeling sources. With crisp, clean tones, multiple sound models, and configurable stereo outputs, the Surface makes a great pair with any stereo effects unit.
Aurora. The latest release from Qu-Bit is once again redefining the world of modular effects. From ambient shimmers to gritty otherworldly textures, the Aurora lives up to its moniker. The front mounted USB port allows for instant updates and program changes too.
The creative folks at Noise Engineering craft an array of unique and thought provoking instruments. Their Versio and Legio series modules all feature stereo capability and span many applications.
Virt Iter Legio. An impressive new digital stereo oscillator, the Virt Iter Legio boasts independent stereo phase inputs and a lush chorus in a mere 6HP. With such a tiny footprint, this oscillator is ideal for beginning your stereo journey.
Polydactyl Versio. Equalization and dynamics processing, unfortunately, often go overlooked when constructing a modular system. The Polydactyl Versio offers an elegant stereo solution in just 10hp. Throw it on the end of the chain to glue your mix together, or toss it on an individual instrument and use the saturation to shape new timbres.
If you want to mix stereo signals within your system, you’ll want to get familiar with a few mixing options first. You may immediately notice that there are many different modules to choose from and that the size, feature set, and cost can vary significantly. Basic stereo mixers like the Doepfer A-138s start around $90, while more professional tools like the WMD Performance Mixer will run you upwards of $1k.
At the most basic level, a stereo mixer should contain multiple inputs, amplitude controls, and a set of outputs. You may come across other features in some mixers like internal VCAs, channel panning, auxiliary sends, mutes, or CV inputs for any of the aforementioned, and while it’s great to have these additional utilities built in, they’re not necessary to begin mixing stereo signals. Two individual monophonic mixers can act as either the left or right channels. Consider combining the power of multiple modules to achieve a stereo effect.
The word “trend” seemed to present itself often when discussing this topic with other modular users. So, is stereo just a trend? I don’t think so. I see it as a new and welcome direction for the format. It’s hard for me to view this as anything but an improvement on something that’s already awesome. The nature of the instrument has always been innovation for the sake of creativity.
With leading companies focused more on stereo releases and younger users adopting modular all the time, it looks to me like stereo is here to stay, and personally, I’m excited! Once again, the Eurorack community has saved itself from redundancy and continues to offer users new and fresh ways to create and play with sound.