ADDAC System 805.VS2 (–)

When you need to move signals around like a sonic air traffic controller — and do it with CV precision — this is the module that doesn’t flinch.

Overview

The ADDAC System 805.VS2 VC Signal Router isn’t flashy, but in a modular setup where routing flexibility separates the functional from the inspired, it’s a quiet powerhouse. Officially known as the ADDAC805.VS2, this Eurorack module does one job with surgical clarity: moving and blending audio and control voltage signals across multiple channels with voltage control. It’s not a synth voice, not an effects processor — it’s the connective tissue that lets you rewire your patch on the fly, morph between sources, or build evolving stereo scenes without lifting a cable.

Born from ADDAC’s own legacy, the 805.VS2 takes cues from the ADDAC701 VCO’s waveform mixing section and evolves the company’s earlier X-Fade/Panner concept into a full stereo voltage-controlled signal router. The result? A module that handles both audio and CV with equal ease, offering real-time crossfading, panning, and what ADDAC calls “4 quadrant mixing” — a technique that lets you manipulate signal polarity and routing in ways that go beyond simple left-right balance. It’s the kind of module you don’t know you need until you realize how static your patches have become.

And while it doesn’t generate sound, its role is anything but passive. With 24 input channels — each capable of handling either audio or CV — and 12 outputs, the 805.VS2 becomes a central nervous node in complex systems. Whether you’re blending drum layers, modulating filter banks, or dynamically shifting stereo imagery, it gives you the tools to do it musically, not just technically. The fully analog audio path uses high-quality, low-noise VCAs, so you’re not sacrificing sonic integrity for flexibility.

Specifications

Manufacturer	ADDAC System
Dimensions	8 HP
Depth	45 mm
Current Draw	40 mA +12V, 40 mA -12V, 0 mA 5V
Signal input	+/- 10V
CV input	+/- 5V
Features	6 mono inputs
Features	2 dedicated X-faders with Control knob + CV Input and Attenuverter
Features	Stereo direct inputs
Features	Mono Sum output
Audio path	Fully analog audio path with high quality/low noise VCAs
Features	The module features two dedicated X-faders and a stereo VCA that can also be used as a third X-Fader
Features	The module is equipped with 24 input channels, each capable of accepting both CV and audio signals
Features	The module features 12 output channels
Features	The module has reversible attenuators on the CV inputs

Key Features

Two X-Faders and a Hidden Third

At its core, the 805.VS2 gives you two dedicated X-faders, each with a manual control knob, CV input, and attenuverter — meaning you can invert the CV signal’s polarity on the fly. This is crucial for bidirectional modulation, like having a filter sweep forward and backward depending on the control voltage. But here’s the twist: the stereo VCA can double as a third X-fader. That means you’re not just limited to two parallel crossfades; you can route a third pair of sources into the stereo master and modulate their balance independently. It’s a clever bit of design that multiplies the module’s utility without adding clutter.

24 Inputs, 12 Outputs — All Flexible

The numbers alone tell part of the story: 24 input channels and 12 outputs. But what makes this impressive is that every input can handle both audio and CV. This blurs the line between audio routing and modulation routing, letting you use the same module to crossfade between drum loops and LFOs alike. No need to dedicate separate mixers or routers — the 805.VS2 handles both domains seamlessly. The 6 mono inputs and stereo direct inputs are clearly laid out, but the real power lies in how they feed into the internal matrix, enabling complex signal choreography.

4 Quadrant Mixing via Stereo Master

ADDAC’s “4 quadrant mixing” isn’t just marketing jargon — it’s a real routing trick enabled by using the stereo master as an X-fader between left and right channels. By manipulating both amplitude and polarity, you can create phase cancellations, polarity-flipped blends, and dynamic stereo imaging that shifts in unpredictable but musical ways. It’s particularly effective when used with feedback patches or stereo effects returns, where subtle shifts in balance can dramatically alter the texture.

Reversible Attenuators — A Game Changer

One of the standout details is the reversible attenuators on the CV inputs. Most modules let you scale a CV signal down, but few let you flip its polarity without patching through an inverter. Here, a simple switch lets you go from “more brightness with increased CV” to “less brightness” — a small thing that saves cables and mental overhead. As one MOD WIGGLER reviewer put it: “X-Pan has fixed routing and has no CV attenuators, whereas the ADDAC805.VS2 has plenty of routing options and reversible attenuators on the CV inputs.” That flexibility is exactly what makes it feel modern, even in a format where minimalism often wins.

Build Quality: Nutless Jacks and Solid Feel

Owners have noted the excellent build quality, with one reviewer (Richard Brewster, Electronic Sounds) remarking it was the first time they’d seen nutless jacks used on a panel. These jacks are mounted directly through the front panel without the usual locking nuts, giving a cleaner, more industrial look — and potentially reducing panel stress over time. It’s a small detail, but one that signals ADDAC’s attention to mechanical design, not just circuitry.

Historical Context

The ADDAC805.VS2 is part of the ADDAC800 series, a lineup categorized under “Analog Sound Utilities” on the manufacturer’s website. It was designed as an evolution of the company’s earlier X-Fade/Panner concept, specifically inspired by the waveform mixing section of the ADDAC701 VCO. By updating that design to a stereo configuration and expanding its routing capabilities, ADDAC positioned the 805.VS2 as a more versatile, modern solution for modular signal management. While no specific release year has been confirmed, its design philosophy reflects a shift toward multi-role utility modules in Eurorack — tools that don’t generate sound but enable more expressive use of those that do.

Collectibility & Value

The ADDAC805.VS2 is not a rare unicorn, but it’s not a commodity either. New assembled units have been listed at $195.00 (Perfect Circuit, circa 2018) and resale prices range from $229.00 to $645.73, suggesting variability in condition, region, or seller markup. For the DIY-inclined, kits were available from ADDAC System at 129€ (excl. VAT), while Thonk offered kit prices between £24.75 and £29.25 — a significant savings, though assembly requires skill.

There’s no widespread report of chronic failures, but at least one documented issue exists: a gain problem that ADDAC addressed with a DIY fix, shared via Pugix.com. This suggests the company supported owners post-purchase, which bodes well for long-term usability. User feedback is sparse but positive — described as a “great voltage controlled crossfader” and “quite a nice module,” with one reviewer noting its superior flexibility over comparable modules like the X-Pan.

Given its utility and solid build, the 805.VS2 holds value well for a niche signal router. It’s not a showstopper on a rack, but for modular users who patch dynamically, it’s the kind of module that quietly becomes indispensable.