ADDAC 213A (2017–)

Turns modular cable chaos into clean, expandable signal highways.

Overview

Hundreds of patch cables snake between cases. The tangle takes an hour to reconfigure between sets, and in a live rack one tug could silence the whole system. The ADDAC 213A is two unassuming black panels, each just 6 HP wide, and it replaces that jungle with a single ribbon. Plug a 50cm ribbon between two 213As and eight CV or audio signals cross between cases without a single patch cable. It isn't a sound module. It won't make a bleep or a drone. What it solves is inter-case connectivity.

Launched in 2017 and still in production, the 213A is part of ADDAC System's Eurorack Bridge concept, a modular utility suite built for real-world workflow. There are no blinking lights, no knobs and no patch points on the front panel. It sends or receives eight signals (CV or audio) over a single ribbon cable. Pair two modules, connect them with ribbon, and your desktop case talks to your main rig like they share a bus board. No power draw. No conversion. The transfer is passive and direct, so there's no coloration, and early tests by users and the designer showed negligible voltage drop even over 30 meters. Touring musicians can't afford a ground loop or a drifting pitch CV, and this avoids both.

The 213A isn't only for gigging players with three cases and a flight case budget. It's for anyone whose rack has outgrown a single frame. It works like Ethernet for modular: low-level plumbing that lets you scale up. Stacking two cases vertically? Bridge them with a 213A and a short ribbon. Sharing clock, gate, and three audio outs from your sequencer case to your effects case? Same thing. Connecting to a friend's system for a live collaboration? Plug in and play. There's no firmware, no configuration and no learning curve. Pair, patch, and forget. When you need to reconfigure, it takes seconds instead of minutes.

Specifications

Manufacturer	ADDAC System
Production Years	2017–
Original Price	$54 per module (sold in pairs)
Module Type	Eurorack Utility / Signal Bridge
HP	6
Depth	24 mm
Current Draw	0 mA (passive)
Signal Channels	8 (CV or audio)
Cable Type	Ribbon cable (IDC 10-pin, 2.54mm pitch)
Standard Cable Length	50 cm or 100 cm (custom lengths available)
Expansion Support	Compatible with ADDAC 213B (adds 8 or 16 channels)
Mounting	Standard Eurorack 3U panel, M3 screws
Color	Black anodized aluminum
Weight	42 g per module
Operating Temperature	0°C to 40°C
Compatibility	All Eurorack cases with standard power and spacing
Country of Origin	Portugal
Model Number	ADDAC213A

Key Features

Passive Signal Transfer, Zero Power Draw

The 213A's most unusual feature is that it does nothing. There's no active circuitry and no power required. It's a dumb pass-through, with eight signal lines routed directly from one module to another via ribbon cable. That means no noise, no distortion, no latency, and no power consumption. In a format where every milliamp counts and noise floors are a constant fight, a module that adds zero load while solving a major routing problem is a good deal. It's reliable too: no chips to fail, no firmware to brick, no heat to dissipate. If a 213A stops working, it's almost certainly a bent pin or a damaged ribbon, not a dead component.

Expandable Architecture with 213B

A single 213A pair handles eight signals. To go past that, ADDAC makes the 213B expander. Two 213Bs can be daisy-chained to a single 213A, adding 8 or 16 more channels for a total of 24. Users with large multi-case systems routinely run 213A + dual 213B setups to bridge entire rigs. The expanders mount directly to the 213A using the same ribbon connectors. The system supports both normal and inverted (180° flipped) mounting, which helps in tight spaces or stacked cases.

Inter-Case and Inter-Personal Connectivity

The 213A isn't only for solo use. Connecting your case to a friend's with a single ribbon, say to share clock, gate, and a couple of audio outs, turns a modular jam from a patch-cable wrestling match into something quick. The ribbon cables are standard IDC types, so replacements are cheap and available worldwide. There are no proprietary connectors to hunt down when you're on tour in Berlin or Buenos Aires.

Historical Context

When the 213A debuted in 2017, Eurorack was deep into its expansion phase. Racks were getting bigger, more complex, and more mobile, but the infrastructure hadn't caught up. Most builders still relied on patch cables, mults, and DIY solutions to connect multiple cases, which often meant signal degradation, ground loops, or fragile setups. ADDAC, a Portuguese company known for utility modules and vintage-inspired processors, saw the gap. Instead of chasing the latest digital wavetable or FM engine, they focused on workflow. The 213A wasn't the first attempt at inter-case connectivity. It was the first to package it in a simple, passive, expandable format that felt native to Eurorack.

At the time, the alternatives were either clunky (DIY breakout boxes) or over-engineered (active digital converters with latency and power needs). The 213A doesn't digitize or compress signals. It doesn't add MIDI or USB. It just moves analog voltages cleanly. Competitors like Intellijel's Link offered similar concepts but with more complexity and cost. The 213A carved out a niche as the minimalist's solution, for people who wanted utility without feature bloat. Modular was moving from bedroom studios to live stages, and that created demand for quick-setup systems.

Collectibility & Value

The ADDAC 213A is still in production, so it isn't "vintage" in the traditional sense. Pairs are commonly listed between $110 and $160 on the used market, depending on condition and whether they include the original ribbon cable. New units from dealers like Perfect Circuit or Reverb hover around $145 for a pair, a modest markup over the original $54 per module price. The 213A draws no power and has no active components, so used units are generally reliable. Buyers should inspect the IDC connectors for bent pins, the most common failure point. A damaged connector can be repaired, but it takes precision soldering.

Owners report that once they install a bridge, they rarely go back to patch-cable inter-case routing. The 213B add-ons mean early adopters aren't locked into an 8-channel limit. It's not a showpiece, and you won't see it on stage under a spotlight. It does turn up in the racks of touring artists and large-system builders.