ADDAC 102 VC FM Radio (2020s)

A working FM radio shoved into a Eurorack case—tunable by hand or voltage, crackling with static, broadcasting ghosts from the electromagnetic ether.

Overview

There’s something deeply absurd, and therefore deeply satisfying, about twisting a knob on your modular synth and suddenly hearing a pop song from 20 miles away. The ADDAC 102 doesn’t just sample radio—it is radio, crammed into 8 HP of analog circuitry with a stubby wire antenna poking out like a periscope from a submarine. It doesn’t try to clean up the signal or digitize the experience. Instead, it leans into the mess: the hiss, the bleed, the unpredictable bursts of talk-show host laughter or half-heard guitar solos that vanish as quickly as they appear. You’re not just patching in a sound source—you’re inviting chance, interference, and the outside world into your carefully curated voltage landscape.

Originally released in a Version 2 configuration to be “skiff friendly,” the 102 trims its depth down to a manageable 5 cm, making it a rare breed: a full-featured external audio module that won’t topple your desktop setup. It covers the full FM band from 87.5 to 108 MHz, with manual tuning and volume controls, but the real magic lies in the CV inputs. Voltage control over tuning means you can sweep through stations with an LFO, jump to specific frequencies via sequencer, or modulate the dial with chaotic sources to produce unpredictable bursts of audio collage. The volume is also CV-controllable, with attenuverters that let you invert or scale the incoming control voltage—handy for ducking the broadcast when your own sequence hits a climax.

But the 102 isn’t just for eavesdropping. Turn the dial between stations and you’re greeted with a wall of analog noise—rich, textured, and full of electromagnetic artifacts that no noise generator can truly replicate. This isn’t white noise from a chip; it’s the sound of the air itself, humming with power lines, cell towers, and forgotten transmissions. Patch that static into a filter, modulate it with an envelope, and you’ve got a sound source that feels alive, unpredictable, and deeply organic. It’s no surprise that experimental composers and noise artists have gravitated toward this module—not for its fidelity, but for its flaws.

Specifications

Manufacturer	ADDAC System
Production Years	2020s
Original Price	€315
Format	Eurorack
Width	8 HP
Depth	5 cm
Power Supply	±12V or ±15V
Max Current Draw	100 mA
Bus Board Connector	8×2 IDC (Doepfer style)
Frequency Range	87.5 – 108 MHz
Regional Tuning	EU (100 kHz steps), US (200 kHz steps), firmware available for Japan (76–96 MHz)
CV Inputs	Tune (±10V), Volume (±10V) with attenuverters
Gate Input Threshold	2.5V
Outputs	Stereo audio (two 3.5mm jacks)
Controls	Tune knob, Volume knob, Mute button, Seek Up/Down, Search Up/Down
Indicators	Stereo output LED
Antenna	External wire antenna via 2.5mm jack
Jumpers	Soft Mute (ON/OFF), Region (EU/US)

Key Features

Voltage-Controlled Tuning and Volume

The ADDAC 102 doesn’t just sit there receiving—it responds. The CV input for tuning allows full voltage control over the selected frequency, meaning you can automate station changes with precision or chaos, depending on your patch. Want to sweep through the dial every eight bars? Route a slow triangle LFO into the tune CV with the attenuverter set to taste. Prefer to jump unpredictably between news, classical, and static? Feed in a sample-and-hold voltage from a noise source. The volume CV input works similarly, letting you duck the broadcast when your main sequence plays or create rhythmic mutes in time with a clock signal. These aren’t gimmicks—they’re compositional tools, turning the radio from a passive listener into an active participant in your patch.

Stereo Output with Real-World Artifacts

Most Eurorack modules are monophonic or offer stereo through duplication. The 102, however, delivers true stereo FM output—when you hit a strong station, you’ll hear the left and right channels drift in and out of phase, just like a car radio in a tunnel. But even more valuable is what happens when you’re not on a station. The stereo field fills with asymmetrical noise, phasey interference, and random bursts of signal that feel spatially complex in a way that mono noise can’t match. Patch both outputs into separate filter channels, pan them hard, and modulate each independently—suddenly you’ve got an evolving, three-dimensional soundscape born from the ether.

Jumper-Selectable Behavior for Creative Control

Two tiny jumpers on the back of the PCB give you deep control over how the module behaves. The first toggles “soft mute,” a digital feature that silences the output when no station is detected. Most users leave this off—after all, the static is the point. The second jumper sets the tuning step: EU mode (100 kHz) or US mode (200 kHz). But here’s the trick—using the EU setting in the US (or vice versa) doesn’t break the module; it just changes the granularity of your search. Some users deliberately mismatch the setting to create uneven station jumps, adding another layer of unpredictability. And for those in Japan, ADDAC offers custom firmware for the 76–96 MHz band, though it’s recommended to order directly from the manufacturer to ensure proper installation.

Historical Context

The ADDAC 102 arrived in the 2020s, a time when Eurorack had already absorbed nearly every conceivable sound-generation method—digital oscillators, granular engines, physical modeling, and beyond. At first glance, a literal FM radio might seem like a novelty, a joke module for the irony-drenched corners of the modular community. But its release coincided with a broader resurgence of interest in “found sound,” circuit bending, and the aesthetic of technological imperfection. As more systems became pristine and digital, the demand grew for modules that could reintroduce chaos, unpredictability, and the outside world.

ADDAC, a Portuguese company known for its thoughtful, hands-on designs, didn’t approach the 102 as a gimmick. Instead, they treated it like any other sonic instrument—something to be patched, modulated, and exploited. The 102 fits into a lineage of experimental radio-based art stretching back to Alvin Lucier’s *I Am Sitting in a Room* and the radio sculptures of Nam June Paik. But unlike those works, which required external receivers and complex setups, the 102 drops that entire concept into a single module. It’s not just a convenience—it’s a philosophical statement about what a synthesizer can be.

Competitors like Intellijel and Mutable Instruments focused on algorithmic complexity or digital precision, but ADDAC went the opposite direction: analog, external, and gloriously unstable. The 102 doesn’t compete with those modules—it complements them, offering a raw, unfiltered connection to the real world that no algorithm can truly simulate.

Collectibility & Value

The ADDAC 102 is not a vintage module in the traditional sense—it’s too new to have aged into classic status—but it has already developed a cult following among modular enthusiasts who value unpredictability and texture. New units sell for around €315, though prices on the secondhand market vary widely depending on condition and location. In the US, used units typically fetch $300–$375, with mint-condition modules from European sellers sometimes commanding higher prices due to shipping and import costs.

Because the 102 relies on analog radio reception, its performance is highly dependent on environment. Units tested in dense urban areas with strong FM signals tend to hold more value than those from rural zones where reception is spotty. The external wire antenna is fragile and often replaced or extended by owners, so buyers should check for continuity and proper soldering at the 2.5mm jack. The module draws 100 mA, which is moderate but not trivial—users with underpowered cases may experience noise or dropout, especially when combined with other high-draw modules.

Failures are rare but not unheard of. The most common issue is intermittent tuning, usually caused by dirt or oxidation on the tuning potentiometer. A quick cleaning with contact cleaner often resolves it. The soft mute jumper can also cause confusion—some users mistakenly install it expecting cleaner silence, only to realize they’ve disabled the very noise they wanted. There’s no firmware to update, but the Japanese frequency variant requires direct coordination with ADDAC, so buyers should verify firmware compatibility if operating outside Europe or North America.

For collectors, the 102’s real value lies in its uniqueness. It’s not a module you buy for reliability or pristine tone—it’s a wildcard, a wildcard that can turn a sterile patch into something haunted, alive, and slightly dangerous. Those who dismiss it as a novelty often haven’t spent enough time lost in the static between stations, where the real magic lives.