ADDAC 302 CV Mix (2010s)

A no-frills, no-nonsense utility that quietly does the math your patches depend on—until it doesn’t, and you realize just how much you were leaning on it.

Overview

Plug in two control voltages, and the ADDAC 302 CV Mix doesn’t just sum them—it averages them. That subtle distinction is what separates a muddy, overdriven CV chaos from a smooth, musical blend. While most mixers in Eurorack simply add voltages together (which can push signals beyond usable ranges), the 302 takes the arithmetic mean, keeping outputs in the sweet spot between 0V and 5V. It’s the kind of thing you don’t appreciate until you’re knee-deep in a patch where three LFOs are fighting over a filter cutoff, and suddenly, instead of clipping or jumping erratically, everything glides together like it was meant to. This isn’t a flashy module. No blinking lights, no touch plates, no accelerometers—just two inputs, one averaged output, and a dedicated mix output that spits out the midpoint voltage. It’s the silent negotiator in your rack, the diplomat that keeps warring oscillators from destabilizing your sequence.

Designed as part of ADDAC’s 300 Series—labeled “Expressive Controls”—the 302 fits snugly into a philosophy of human-machine interface. But unlike its siblings like the 310 Pressure to CV or the 308 Light to CV, the 302 doesn’t capture gestures or translate physical movement. Instead, it’s a pure utility: a circuit that performs a simple, essential mathematical operation with precision. It’s the module you reach for when you want to crossfade between two pitch sources without jumping octaves, or blend two envelope shapes into a hybrid contour. It’s not generative, not experimental—it’s foundational. And in a format where every HP counts, the 302 packs a surprisingly high utility-to-size ratio into just 4HP.

ADDAC, based in Lisbon, has always leaned into the tactile and the performative, but the 302 is a reminder that their design ethos extends to the quiet, behind-the-scenes workhorses too. It doesn’t demand attention, but it earns respect. The front panel is barebones—black anodized aluminum with white silkscreen, two input jacks, one output, and a small LED to indicate activity. There are no knobs, no switches, no user-adjustable parameters. What you see is what you get: a passive-acting active circuit that does one job and does it well. It’s the kind of module that, once installed, you might forget is even there—until you try to replicate its function with attenuverters and mults and realize how much easier life was with the 302 quietly averaging things in the background.

Specifications

Key Features

Averaging, Not Summing

Most mixers in Eurorack are summing amplifiers—they add input voltages together, which means two 5V signals become 10V, potentially overloading downstream modules. The 302, however, outputs the average of the two inputs. Two 5V signals yield 5V, two 0V signals yield 0V, and a 5V and a 0V input give you a stable 2.5V. This behavior is invaluable when blending control voltages where headroom matters—like pitch, where a sudden voltage jump can send your oscillator into another octave. It’s also ideal for morphing between modulation sources: imagine crossfading between a slow sine LFO and a random sample-and-hold, with the 302 ensuring the transition stays within a predictable voltage window. The result is smoother, more musical modulation without the need for additional attenuators or offset controls.

Silent Workhorse Design

There’s no user interface to speak of—no knobs, no switches, no menu diving. The 302 is set-and-forget. Once patched, it operates transparently, which is exactly what you want from a utility module. The lack of controls isn’t a limitation; it’s a feature. It forces intentionality in patching, knowing that what goes in is mathematically transformed and passed on without coloration. The LED is subtle but useful—a small red glow confirms signal flow without drawing attention. The 4HP width makes it easy to tuck into tight racks, and the 40mm depth ensures it fits in most skiffs. It’s not the flashiest thing on the shelf, but it’s the one you’ll miss most if it fails.

Integration in the 300 Series

Sitting among gesture-based controllers like the muscle sensor, pressure pipe, and light detector, the 302 stands out for its abstraction. While other 300 Series modules translate physical movement into voltage, the 302 operates at the level of pure signal logic. It doesn’t care where the CV comes from—whether it’s from a sequencer, an envelope, or a solar panel—it just does the math. This makes it a natural companion to modules like the ADDAC 301 Floor Control or 310 Pressure to CV, where you might want to blend multiple expressive inputs into a single, balanced control stream. It’s the bridge between the performative and the procedural, letting you combine human expression with algorithmic precision.

Historical Context

The 302 emerged during the mid-2010s Eurorack boom, when racks were growing faster than patch cables could keep up. As modular systems became more complex, the need for intelligent utilities grew. While early adopters cobbled together mixing solutions using audio mixers or op-amp circuits, manufacturers began releasing dedicated CV mixers with features tailored to control voltage behavior. ADDAC’s approach with the 302 was minimalist: rather than adding attenuation, inversion, or offset, they focused on a single, often-overlooked function—averaging. At a time when many companies were packing modules with features, ADDAC went the opposite direction, betting that simplicity had value.

It arrived alongside a wave of Portuguese and European boutique manufacturers—Joranalogue, Intellijel, Mutable Instruments—who were redefining what modular could be: not just a collection of sound generators and processors, but a system of interconnected ideas. The 302 didn’t make noise, but it shaped how noise (and control) moved through the system. Competitors like the Intellijel Mutamix or the Doepfer A-138c offered more inputs and flexibility, but they summed rather than averaged. The 302 filled a niche that most didn’t know existed—until they tried to blend CV sources without jumping voltage rails. It wasn’t a headline-grabber, but it became a quiet staple for those who valued precision over flash.

Collectibility & Value

The ADDAC 302 CV Mix isn’t a collector’s item in the traditional sense. It doesn’t have limited editions, hand-painted panels, or cult mystique. It’s not the kind of module people flip for profit. But that doesn’t mean it’s not valuable—quite the opposite. On the secondhand market, it typically sells for $80–$120 in working condition, depending on regional availability and rack scarcity. Units with damaged jacks or oxidized power connectors can be found cheaper, but repairs are straightforward for anyone with basic soldering skills. The most common failure points are the 3.5mm jacks, which can loosen over time due to frequent patching, and the IDC connector, which may develop intermittent contact if the ribbon cable isn’t seated properly.

Because it contains no active user controls or delicate sensors, the 302 is one of the most reliable modules in the ADDAC lineup. There are no pots to wear out, no membranes to degrade, no moving parts. The circuit is simple, built around standard op-amps and passive components, making it easy to troubleshoot and repair. That reliability, combined with its niche function, means that while it’s not rare, it’s rarely sold. Owners tend to hang onto it once they’ve integrated it into their workflow. When buying used, check that the LED responds to input signals and that the output voltage matches the calculated average of the inputs—simple tests that confirm the core function is intact. Power cycling issues are rare but can occur if the module shares a crowded bus board; ensure your power supply can handle the 100mA draw, especially in larger systems.

It’s worth noting that while the 302 is not obsolete, newer modules like the ALM 0-Coast or the Intellijel Quad VCA offer voltage averaging as part of broader feature sets. But if you want a dedicated, skiff-friendly, no-compromise averager, the 302 remains one of the few purpose-built options. It’s not the cheapest way to average two CVs—some DIY builders replicate the function with a few resistors—but for those who value tested, compact, and reliable hardware, the 302 is still a smart buy.

eBay Listings

As an eBay Partner, we earn from qualifying purchases. This helps support our independent vintage technology research.

Related Models

• ADDAC 200PI Pedal Integrator
• ADDAC 816
• ADDAC 100 Series
• ADDAC 101 .WAV Player
• ADDAC 102
• 4ms Ping
• ADC 27
• 2hp LPG V2
• ALM AXON-2
• AMS DMX 2000