ADDAC 306 VC Transitions (2019–Present)

A five-channel CV morphing engine that turns a single slider into a live performance controller.

Overview

Slide your finger across the ADDAC 306's central fader and five independent control voltages shift in real time. Each one moves from one state to another, but not necessarily in the same direction or at the same rate. It's not a sequencer, not a random source, not a plain attenuator. It's a macro controller in an 8HP module, built for performers who want to morph entire patches with one hand while tweaking with the other. It has five channels, each with MINIMUM, SPAN, and DIRECTION controls, all governed by a single TRANSITION CONTROLLER slider. Set your endpoints - say, a filter sweep, a delay feedback climb, a resonance spike, a pitch bend, and an LFO rate increase - then slide from "calm" to "chaos" in one motion. Or reverse the direction on one channel so it winds down while the others ramp up. Think of it as five automation lanes under one fader, each with its own range and polarity, all synchronized.

The 306 is small, but it does a lot. Need to move between two very different timbres during a live set? Patch the outputs to key parameters on your oscillators, filters, and effects, dial in your A and B states, and let the slider do the rest. Want five different envelope shapes from a single ADSR? Route the envelope into the CV IN, set each channel's SPAN and MINIMUM differently, and one transient becomes five evolving control voltages. It also works as a polyphony multiplier. Pair it with a quantizer like the ADDAC207, feed it a single-note sequence, and you can morph between chord voicings in real time. The module doesn't generate sound, but it shapes the behavior of everything around it.

Specifications

Manufacturer	ADDAC System
Production Years	2019–Present
Original Price	€130 (assembled), €87 (DIY kit)
Format	Eurorack
Width	8 HP
Depth	40 mm
Power Consumption	+40mA / -20mA
Bus Board Connector	8×2 IDC (Doepfer style)
CV Inputs	1 (CV IN, accepts up to +5V)
CV Outputs	5 (individual per channel)
Output Voltage Range	Jumper selectable: +5V or +10V maximum per channel
Minimum Voltage Control	Per channel, adjustable via front panel knob
Span Control	Per channel, sets voltage range above minimum
Direction Control	Per channel, toggle switch for min→max or max→min transition
Transition Control	Manual slider (0–10V range) or CV-controlled via CV IN
Attenuation	Slider acts as attenuator when CV IN is used
Jumpers	5 rear-mounted jumpers to set max output range per channel
DIY Availability	Yes, full kit available

Key Features

The Morphing Slider as Performance Interface

The heart of the ADDAC 306 is its central slider—a tactile, smooth-moving fader that feels more like a studio automation controller than a typical modular knob. This isn’t just for show; it’s the primary performance interface. Whether you’re using it manually or driving it with an external CV, the slider governs the transition state across all five channels simultaneously. Move it from bottom to top, and each channel moves from its MINIMUM to its maximum (or vice versa, depending on DIRECTION). The brilliance is in the independence: one channel might go from 1V to 5V (SPAN of 4V), another from 3V to 8V (SPAN of 5V), while a third drops from 6V to 2V. The slider doesn’t output a fixed voltage—it outputs progress, and each channel interprets that progress differently. This makes it ideal for complex, non-linear transitions that would take multiple sequencers or complex logic to replicate.

CV Input for External Automation

The manual slider is expressive, but the CV IN jack turns the module into a signal processor. Feed it an LFO, envelope, or sequencer output, and the slider becomes an attenuator for that incoming signal. So you can automate the whole morph - have an ADSR trigger a smooth shift from one patch state to another every time you hit a key. Because the slider attenuates the CV, you can scale the transition depth. Set it halfway and you only get a partial morph, even if the incoming CV swings full range. That kind of dynamic control is rare in modules of this class. You can also chain units. Patch the output of one 306 into the CV IN of a second to get cascading transitions, or put multiple units under a single master slider for 10-channel control.

Jumper-Selectable Output Ranges

On the back of the module, five jumpers set the maximum output range for each channel independently, either +5V or +10V. Need one channel to drive a 1V/oct pitch input? Set it to 5V range and dial in a 1V SPAN. Want another to modulate a filter with a wide 8V sweep? Set that channel to 10V and adjust accordingly. The jumpers let the module fit a range of modular standards without external offset or attenuverters.

Historical Context

The ADDAC 306 arrived in 2019, when Eurorack was shifting from experimental hobbyism to serious performance instruments. Modularists were taking systems on stage, and they needed tools that could handle real-time control with reliability and immediacy. Modules like the Intellijel Metropolis or Make Noise Pressure Points offered deep performance control, but they were complex and expensive. The 306 was a focused, affordable utility that solved one specific problem: how to smoothly transition between two patch states without resorting to multiple sequencers, mixers, or logic modules.

It appeared alongside a wave of "macro control" modules, tools designed to manage multiple parameters at once. Where something like the ALM Trogotronic or the Qu-Bit Velocity offered digital scene recall or velocity processing, the 306 stayed analog and hands-on. It didn't store presets or respond to MIDI. It responded to touch and voltage. That made it a favorite among performers who valued tactile feedback over digital recall. Its design also echoed the "patch programmability" ethos of modules like the Cold Mac, without the steep learning curve.

Collectibility & Value

As of 2026, the ADDAC 306 remains in production and widely available, which keeps prices stable. New units typically sell for between €130 and €160, depending on region and distributor. DIY kits are available for €87, making it one of the more affordable entry points into ADDAC's ecosystem. Used prices on the secondhand market hover between €90 and €120, with most units selling in "like new" condition due to the module's solid build and lack of moving parts beyond the slider. The fader is the only wear item, and while it's a high-quality component, heavy stage use over years could lead to scratchiness or dropouts. No widespread failure modes have been reported, and the PCB is straightforward with no known design flaws.

Because the module is still current, it's not yet a "vintage collectible" in the traditional sense, but it has a loyal following among modular performers. Units with custom front panels (offered directly by ADDAC in colors like red, blue, or bronze) occasionally fetch a premium, especially if paired with matching cases or other ADDAC modules. For buyers, the main concern is verifying that all five outputs respond linearly to the slider and that the CV IN properly attenuates incoming signals. A quick test with a multimeter or oscilloscope will confirm functionality. The 306 is one of the safer buys in the Eurorack market - no capacitor leaks, no firmware issues.