ADDAC 200CT (2024)
A desktop cable tester for Eurorack that catches bad ribbon cables before they fry your modules
Overview
You plug in your rack, power it up, and get silence. Or a high-pitched whine, a module running hot, or a complete system crash. The cause is often a bad ribbon cable or a miswired busboard. It's not the flashiest failure, but it's one of the most common, and it can be prevented. The ADDAC 200CT Cable Tester is a small box that does one job. It doesn't make sound. It checks that power and signal paths are intact before they touch your oscillators and filters.
Born in Lisbon and released in March 2024, the 200CT was designed for the messy reality of Eurorack ownership, where ribbon cables get yanked, pins bend, and DIY builds can have hidden flaws. It's for troubleshooting after a disaster, and also for setup, expansion, or routine cable swaps. The 200CT checks continuity across both power and signal lines, with dedicated testing for ADDAC's own busboard systems (like the 112, 213, and 807). It works with any Eurorack setup using standard 16-pin or 10-pin ribbon cables. You don't know you need one until you fry a module, and then you'll wish you'd bought two.
Specifications
| Manufacturer | ADDAC System |
| Production Years | 2024–present |
| Original Price | $79 USD |
| Type | Eurorack cable and busboard tester |
| Compatibility | 16-pin and 10-pin Eurorack ribbon cables, ADDAC 112/213/807 busboards |
| Test Functions | Continuity, short detection, pinout verification |
| Interface | Two 3.5mm jack sockets, LED indicators |
| Power Source | Bus power via included 3-foot test ribbon cable |
| Dimensions | Desktop unit with compact footprint (exact mm not specified) |
| Weight | Lightweight, plastic housing |
| Accessories | 3-foot ribbon cable for power connection |
| Country of Origin | Portugal |
Key Features
Pin-Perfect Continuity Checks
The 200CT doesn't just tell you if a cable works. It tells you exactly which pins are connected, and which aren't. It has two 3.5mm jack sockets, so you can test both patch cables and ribbon cables. When you plug in a cable, LEDs light up to confirm continuity across each conductor. If there's a break or a short, the pattern breaks. It's immediate and visual, and there's no "maybe it's fine" guessing with a newly built cable or a salvaged busboard. This matters most for power cables, where a reversed or shorted pin can destroy multiple modules in seconds.
Built for ADDAC, Useful for Everyone
The 200CT is optimized for ADDAC's own ecosystem, particularly their 112, 213, and 807 ribbon cable systems, but it's not locked in. Eurorack builders and technicians report using it successfully with Doepfer, TipTop, and other third-party busboards. It comes with a 3-foot ribbon cable, so you can power the tester directly from your rack and keep it on hand during builds or repairs.
No Firmware, No Frills, No Failures
There's no software, no firmware updates, no menu diving. The 200CT is purely analog in function: just connections, LEDs, and logic. That means it won't crash, won't glitch, and won't need recalibration. It lives on the desktop and stays compact and simple.
Historical Context
The 200CT arrived at a time when Eurorack is more accessible than ever, but also more complex. As racks grow larger and more modular, the number of interconnections multiplies, and so do the chances of a wiring error. ADDAC has long focused on creative sound-shaping modules, and the 200CT is a move toward infrastructure. It follows the tradition of utility modules like mults, attenuators, and power monitors, but steps off the rack entirely to become a standalone safeguard. A single bad cable can cost hundreds in damaged gear, so the 200CT is economical as well as convenient. It's also part of a growing trend of manufacturers offering diagnostic tools.
Collectibility & Value
As a diagnostic tool rather than a sound-generating module, the ADDAC 200CT isn't collected in the traditional sense. There are no limited editions, no color variants, and no resale market driven by rarity. Its value lies in utility, not aesthetics. At $79, it's an affordable insurance policy for any Eurorack owner. Used units appear occasionally on Reverb or the MOD WIGGLER marketplace, typically selling for $50 - $65 depending on condition. Since it has no moving parts and minimal circuitry, failure rates are extremely low. Most issues reported are related to damaged cables or connectors, not the unit itself. When buying used, check that all LEDs respond and that the included ribbon cable shows no signs of fraying or pin damage. Many owners consider it a must-have, even if it never makes a sound.
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