ADDAC System ADDAC710 (–)

Two channels of clean, transformer-isolated audio exit—without the hum, without the fuss, and without needing phantom power.

Overview

If your modular rig sounds great in the box but turns into a buzzing mess the second you patch it into a mixer, recorder, or PA, the ADDAC710 Balanced Outputs might be the quiet hero you’ve been missing. It’s not flashy, it doesn’t make sounds, and it won’t sequence anything—but what it does is essential. This little 6 HP module takes two unbalanced modular signals and converts them into fully balanced outputs via XLR, using a pair of audio transformers to break ground loops and prevent impedance mismatches. That means no more 50 Hz hum creeping in from studio gear, no more noise when you go live, and no more frustrating troubleshooting sessions chasing ghosts in your signal chain.

Built by ADDAC System as part of their 700 series, the ADDAC710 is a dual-channel isolated DI (direct input) box designed specifically for Eurorack. It’s not trying to color your sound or add character—it’s about transparency and reliability. The core of its design is galvanic isolation: the input and output sides are electrically separated by transformers, so there’s no shared ground path unless you want one. That’s the key to killing ground loops, which are the usual culprits behind that low-frequency drone that gets louder when you plug in more gear.

And while it doesn’t generate audio, its role is sonic hygiene. Think of it like a high-end power conditioner for your signal path—something you don’t notice when it’s working right, but you sure notice when it’s missing.

Specifications

Manufacturer	ADDAC System
Model	ADDAC710 Balanced Outputs
Dimensions	6 HP
Depth	40 mm
Current Draw	40 mA +12V, 40 mA -12V, 0 mA 5V
Transformer type	unity 1:1 type Audio Transformer
Frequency range	20 Hz to 20 KHz
Output connectors	two fully balanced outputs (via XLR connectors)
Ground switch	LIFT/FLOAT/GND 3-way switch
LIFT position details	circuit will be “lifted” to ground through a 100R resistor and a 10nF capacitor
FLOAT position details	Ground will not be shared leaving ins and outs grounds completely apart from each other fully isolating both signals
GND position details	Ground will be shared between inputs and outputs, here no isolation is used
Phantom Power	+48V Phantom Power is NOT needed for the module to operate. Having Phantom Power ON won’t influence the module operation.

Key Features

Transformer-Based Isolation That Just Works

At the heart of the ADDAC710 is a pair of unity 1:1 audio transformers—each handling one channel. These aren’t just passive components; they’re the reason the module can break ground loops while maintaining a full 20 Hz to 20 kHz frequency response. The transformer’s two windings are electrically insulated from each other, creating true galvanic isolation between your modular system and whatever lies beyond the XLR cable. That means your synth stays safely disconnected from the grounding schemes of mixers, audio interfaces, or live sound boards, which often introduce noise when tied directly together.

The transformer used is described as a “low-cost” unit compared to the one in the ADDAC800X, and the manufacturer acknowledges that its frequency response isn’t perfectly flat. Specifically, there’s a -0.2 dB attenuation at 50 Hz—barely perceptible, and likely inaudible in most real-world scenarios. But that slight compromise buys you a smaller footprint and lower price, which is the whole point of this module.

Smart Grounding Control: LIFT, FLOAT, or GND

One of the standout features is the 3-way ground switch per channel: LIFT, FLOAT, and GND. This isn’t just a gimmick—it’s a practical toolkit for noise hunting. In GND mode, input and output grounds are tied together, so there’s no isolation. That might be useful if you’re feeding a device that expects a common ground and you’re not experiencing noise. In FLOAT mode, the grounds are completely separated—maximum isolation, ideal for breaking stubborn hums. LIFT is a middle ground: the output is connected to ground through a 100-ohm resistor and a 10nF capacitor, which allows some grounding for stability while still breaking direct current paths that cause noise. It’s a nuanced control that gives you real-time troubleshooting power without opening your case or repatching cables.

Compact, Shallow, and Phantom Power Independent

At only 40 mm deep, the ADDAC710 is built to fit in shallow Eurorack cases where space is tight. That’s a direct result of using a smaller transformer than the one in the ADDAC800X, which was part of a deliberate redesign to reduce depth. It draws 40 mA on both the +12V and -12V rails, with zero draw on 5V—standard for passive audio modules. And critically, it does not require phantom power to operate. Even if your mixer sends +48V down the XLR cable, it won’t affect the module’s function. That’s a relief, because accidentally sending phantom power into a sensitive input can fry gear—but here, it’s harmless. The manual explicitly states it, and that peace of mind matters when you’re plugging into unfamiliar systems.

A Budget-Friendly Alternative to the ADDAC800X

The ADDAC710 exists as a more affordable, stripped-down sibling to the ADDAC800X High-End Outputs module. It shares the same mission—clean, isolated balanced outputs—but achieves it with a lower-cost transformer and a simplified design. It lacks some of the features of the 800X (though the exact differences aren’t detailed), but it retains the core functionality. For many users, that’s more than enough. If you’re building a portable modular rig or just want reliable outputs without spending top dollar, the 710 hits a sweet spot. It’s also set to be available as a full DIY kit, which will appeal to builders who want to save money or enjoy the hands-on process.

Collectibility & Value

The ADDAC710 is currently listed at $189 by ModularGrid, which is treated as the primary price reference. However, Perfect Circuit lists a pre-order price of $219, suggesting potential fluctuations or regional differences. As a new-release module with no known production start date or original launch price, it’s too early to assess long-term collectibility. There’s no data on common failures, maintenance needs, or repair complexity—likely because it’s a passive, transformer-based design with few failure points. The DIY kit option may influence availability and secondhand pricing down the line, but for now, it’s a functional, modern module aimed at solving a real-world problem, not a vintage artifact. Its value lies in utility, not rarity.