ADDAC 300 Series (Announced 2014)

Wires, electrodes, and foot pedals—this is modular synthesis with your whole body, not just your hands.

Overview

The ADDAC 300 Series isn’t about oscillators or filters. It’s about control—unusual, physical, sometimes weirdly intimate control. These Eurorack modules from ADDAC System were built to break the mold of knob-twiddling, offering ways to interact with your modular rig using muscles, pedals, and even power glitches. Announced in January 2014, the series was framed as a set of “new/diferent expression aproaches” and “new interfaces for analog synthesizers”—a mission statement that’s equal parts playful and serious. You won’t find anything here that makes sound on its own, but you will find tools that make your existing modules respond in ways they weren’t designed to. That’s the point: these are gateways between your body and the machine, built for performers who want to move beyond the keyboard-and-patch-cable paradigm.

At the core of the series are modules like the ADDAC301 Floor Control and ADDAC301B Dual Expression Attenuator, which bring pedal-based expression into the Eurorack world with surgical precision. Then there’s the ADDAC303 Muscle Sensing—a module that feels like science fiction, reading muscle tension through electrodes and turning flexes into control voltages. And lurking in the background is the ADDAC300 Power Starvation, a nod to circuit-bending culture that lets you underpower other modules to induce glitchy, unstable behavior. It’s not flashy, but it’s deeply clever. These aren’t utility modules in the boring sense; they’re utility modules with attitude. And yes, they’re all bright red—something one forum user openly questioned, wondering if they were the only one held back by the color. But that red? It’s a warning label: this gear doesn’t play by the rules.

Specifications

Key Features

ADDAC300 Power Starvation: Starve It to Make It Sing

This module takes a staple of circuit bending—the deliberate underpowering of chips to create glitchy, unstable tones—and makes it modular. You plug another module through it, and then use trimmers to adjust the ± power supply independently, even setting a minimum voltage plateau so things don’t collapse entirely. It’s not destructive (when used carefully), but it will push your gear into sonic territories it was never meant to explore. The idea, as ADDAC put it, is rooted in the first hack any DIYer learns: power starvation. Now it’s in a 4 HP slot, with bypass switches so you can flip back to normal operation instantly. It’s a mischief module, and it draws only 5mA—barely a sip from your power supply.

ADDAC301 Floor Control: Feet on the Controls

While your hands are busy patching or playing keys, your feet are free—so why not put them to work? The ADDAC301 Floor Control lets you plug in standard expression and sustain pedals, giving you real-time control over CV parameters. The Range knob sets the voltage swing from -10V to +10V, while the Offset knob shifts that entire range up or down by ±5V. That kind of precision means you can map a pedal’s motion exactly where you need it—say, from 2V to 5V for a filter sweep, or -3V to +3V for subtle pitch modulation. It also generates a gate signal from the sustain pedal, with an LED to confirm activity. And it includes a removable +5V adaptor via a jumper, making it compatible with bus boards that need it. At 20mA draw and 4 HP wide, it’s compact but not invisible on your rack.

ADDAC301B & ADDAC301C: Passive Pedal Power

These two are siblings in function but opposites in behavior. The ADDAC301B is a passive dual expression attenuator—plug any CV or audio signal through it, and an expression pedal controls its amplitude. The invert switch lets you flip the pedal’s response, so pushing forward lowers the level instead of raising it. It’s 4 HP wide and only 3 cm deep, making it a space-saver. The ADDAC301C, also passive and 4 HP, does the same but for on/off control via sustain pedals. Plug in an audio or CV source, hit the pedal, and you toggle the signal state. Both are minimalist, no-power-needed solutions for bringing pedal control into patches without eating up current or space.

ADDAC303 Muscle Sensing: Your Biceps as a Synth Controller

This is the showstopper. The ADDAC303 uses electrodes to sense muscle tension—literally turning flexes into control voltages. It ships with electrodes and gives you a Gain knob to set the output range (±10V), an Offset knob to position the baseline, and a Smooth switch to choose between hard or soft transitions. You get both positive and inverted CV outputs, plus a comparator gate output with its own Threshold knob, so you can trigger events when tension crosses a set level. One forum user responded to its announcement with “Mmmm, muscle sensing. Wire me up.”—and honestly, that about sums it up. It’s 4 HP, 4 cm deep, and draws 60mA, which is hefty for a control module but makes sense given the onboard processing. It’s not just novel; it’s a legitimate performance interface for experimental setups.

Historical Context

The ADDAC 300 Series emerged from a desire to expand how we interact with modular systems. As ADDAC System stated, these were “new interfaces for analog synthesizers,” born from the observation that while hands are busy during performance, feet—and bodies—are often idle. The ADDAC301 Floor Control was explicitly conceived to solve that. The Power Starvation module taps into circuit-bending lore, bringing a grassroots hacking technique into the Eurorack ecosystem. And the Muscle Sensing module wasn’t just a gimmick; it was positioned as a “totally new interaction principle for the eurorack format.” All of these modules were part of the “ADDAC300 Expressive Controls Series,” a focused effort to make control itself the instrument.

Collectibility & Value

Original pricing as of January 2014 was: ADDAC300 Power Starvation at 70,00 €, ADDAC301 Floor Control at 70,00 €, ADDAC301B Dual Expression Attenuator at 65,00 €, ADDAC301C Dual Sustain Switcher at 60,00 €, and the ADDAC303 Muscle Sensing at a steep 180,00 €—reflecting its complexity. There is no data on current market prices, production end dates, or common failures. Maintenance and reliability concerns are unreported in the sources. Some users noted the bright red color as a hesitation point, though others found the modules “very handy” and praised ADDAC as a company to deal with. As of now, this series remains a niche but conceptually bold chapter in Eurorack history—collected more for its ideas than its ubiquity.

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