The "Easel" Spirit in 3U - A West Coast Eurorack Deep Dive

video upload by Sean Graves

The following is in via Sean Graves, who had the following to say:

"The piece, 'The 'Easel' Spirit in 3U: Rebuilding a Buchla Soul in Eurorack,' documents my five-year journey to replicate the specific workflow and 'soul' of the Buchla Music Easel using a curated Eurorack system."

"A deep dive into a five-year journey of replicating the Buchla Music Easel’s 'soul' within a 3U Eurorack format. The post explores the creative power of 5-step sequencing (the 'migrating downbeat'), the 'origami' of wavefolding via the Verbos Complex Oscillator, and the organic harmonic dampening of vactrol-based Low Pass Gates. It’s a technical yet accessible look at why the West Coast workflow remains the 'holy grail' for performance - based synthesis."

The full write-up follows. Video of the system above.

The “Easel” Spirit in 3U: Rebuilding a Buchla Soul in Eurorack

The Buchla Music Easel is legendary. It isn’t just a synthesizer. It’s a self-contained performance ecosystem. For many of us, the “Easel” workflow is the holy grail of synthesis. However, instead of chasing original hardware, I’ve spent the past five years rebuilding its specific soul within the Eurorack format. Because everyone deserves a hobby, right?

The Chef vs. The Sculptor
Most East Coast synthesizers work like a sculptor. You start with a massive block of harmonic noise (Sawtooth or Square waves) and carve it away with a filter. The Buchla workflow is different. It’s like being a chef in your own Hell’s Kitchen. You start with basic, “bland” ingredients (sine waves) and spice them up with Frequency Modulation (FM), Amplitude Modulation (AM), your choice, and then fold until the sound sizzles.

My current rig recreates this spirit by focusing on three pillars: Uncertainty, Complex Oscillation, and the iconic Sequential Voltage Source.

Part One: The Modulators (The Brain)
In a true Easel style setup, the Tokyo Tape Music Center 5-Step Sequencer acts as the brain. While most modern sequencers favor 4-8-16-32 steps, the 5-step limitation is actually a creative superpower.

Think of it as a game of musical chairs. Because 5 doesn’t divide evenly into a standard 16 beat phrase, the downbeat constantly migrates. In bar one, the “one” is step one; by bar two, the “one” has shifted to step five. This prevents the ear from getting “parked” in a repetitive loop making the sequence feel like it’s breathing or tumbling forward rather than just marching in place.

Example: X - - - | - X - - | - - X - | - - - X | - - - - |

Function Generation & Chaos
To move the sound, I rely on the Behringer Abacus (you can also use the Make Noise Maths). As a dedicated dual Function Generator, it handles the snappy, percussive “pluck” the Easel is famous for by modulating the amplitude and timbre simultaneously.

But no Buchla - inspired rig is complete without a “Source of Uncertainty.” For this, I use the Make Noise Wogglebug. It provides the organic instability which prevents a sequence from sounding robotic, offering two distinct flavors of chaos:
Smooth Voltages: Like a drifting cloud - gentle, slow and wandering.
Stepped Voltages: Like a toddler hitting random keys on a piano - surprising, energetic, and highly caffeinated.
The circuit for the Wogglebug is absolutely fascinating; even if you think you’ve mastered it, the next patch will teach you something entirely different. The audio sources, Control Voltage (CV) and its Clock/Burst sections can bring a whole patch to life.

Part Two: The Voices (The “Soul”)
The Complex Oscillator
The heart of the system is the Verbos Complex Oscillator, a direct descendant of the legendary Buchla 259, before TipTop Audio started producing the 259t. We aren’t filtering sound down here, we’re using wavefolding.

If standard synthesis is subtractive, wavefolding is like “origami for sound.” You start with a smooth sine wave and “fold” the peaks back into themselves to create sharp corners and metallic textures. By blending this with a Xaoc Zlin crossfader, I can stack these harmonics until they growl. Much like that funny red dial on the Buchla 208 - the Timbre pot - it allows me to blend between a sine wave to a triangle, square or spike wave.

The Low Pass Gate (The “Secret Sauce”)
Finally the signal chain hits the Tokyo Gate, which serves at the Low Pass Gate (LPG). This is the “secret sauce” of the West Coast sound.

Most Voltage Control Amplifier (VCA) based synths sound like a computer turning a sound on and off: click, click, click. However, the Tokyo Gate uses Vactrols, which possess a natural decay. It’s the difference between a light switch and a physical bell. When you “strike” a vactrol based gate, the sound doesn’t just stop. It rings out and fades into darkness, mimicking the physics of a drum skin or a xylophone bar. As the volume drops, the high frequencies drop faster due to harmonic dampening.

Conclusion: A Living System
Everything in this configuration comes together with an Intellijel Mixup before external delay and reverb to mimic that classic Easel spring tank vibe.

The result isn’t just a collection of modules. It’s a living system which surprises me every time I patch it. It doesn’t just play notes… It performs.

#Buchla #Eurorack #WestCoast About the Author: Sean Graves is an American composer, producer, and multi-disciplinary artist. His music project PostOmnis is characterized by its heavy use of modular synthesis, atmospheric soundscapes, and cinematic storytelling. Since its inception in the early 2000s, Sean Graves has evolved from experimental electronic roots into a "post-genre" style of electronic and ambient music which frequently incorporates narrative elements and guest vocalists.