ADDAC 710 Balanced Outputs (2022–)

A quiet workhorse that keeps your modular's voice clean when it hits the outside world

Overview

It doesn't make a sound of its own. But if your Eurorack setup hums, buzzes, or crackles when you patch it into a mixer or audio interface, the ADDAC 710 Balanced Outputs might be the module you need. It isn't a sound generator or processor. It sits between your modular and the grounded reality of studio gear. Plug in your unbalanced 3.5mm modular outputs, flip a switch, and out come balanced XLR signals that ignore ground loops and impedance mismatches. Anyone who has spent an hour chasing noise with a multimeter will see the point.

The 710 is a streamlined alternative to ADDAC's more feature-rich 800X High-End Outputs. It strips things down to two independent channels of transformer-isolated output, each with its own 3.5mm input, clip LED, and XLR output. The 1:1 audio transformers give galvanic isolation, which breaks the electrical continuity between your modular and downstream gear. That means no shared ground, no sneaky current flows, and - if you set it right - no hum.

Specifications

Manufacturer	ADDAC System
Production Years	2022–
Original Price	€160 (assembled), €105 (DIY kit, excl. VAT)
Format	Eurorack
Width	6 HP
Depth	40 mm
Power Consumption +12V	40 mA
Power Consumption -12V	40 mA
Inputs	2 x 3.5 mm jack (unbalanced)
Outputs	2 x XLR (balanced)
Transformer Type	1:1 unity audio transformer
Frequency Response	20 Hz – 20 kHz
Ground Lift Options	Lift (via 100Ω resistor + 10nF cap), Float (fully isolated), Ground (shared)
Clip Indicator	LED per channel
Panel Material	Black anodized aluminum
DIY Availability	Yes, SMD/through-hole hybrid kit

Key Features

Transformer Isolation That Actually Works

The 710 doesn't use active electronics or digital tricks. It uses real analog transformers for galvanic isolation. Each channel's 1:1 transformer passes the signal without distortion while breaking any direct electrical connection. That matters in modular setups, where ground loops are the usual suspects behind low-frequency hum. The transformer's frequency response covers the full audible spectrum, so there's no roll-off or coloration to muddy your bass or dull your highs. It's transparent by design.

Three-Way Ground Control: Lift, Float, or Ground

What sets the 710 apart from basic DI boxes is its three-position ground switch per channel - Lift, Float, and Ground. Lift connects the ground through a 100Ω resistor and 10nF capacitor. It's a compromise that often kills hum without fully disconnecting. Float completely isolates input and output grounds, which helps when you have multiple grounded devices in a complex chain. Ground simply ties everything together. That might be necessary in some setups, but it risks bringing back the noise you're trying to avoid. You can toggle between these on the fly, so the module adapts to a simple laptop rig or a full patch bay with outboard gear. The wrong setting leaves you with a 50/60 Hz drone.

DIY-Friendly Design with Real Build Flexibility

The 710 is available as a DIY kit that includes both SMD and through-hole components, rated "Easy/Medium" in difficulty. The manual is thorough, and the layout is clean, with clearly labeled silkscreen and well-spaced pads. ADDAC also offers custom front panels in a range of colors - bronze, silver, red, green, and more - though they come with a wait and a price bump.

Historical Context

The ADDAC 710 arrived in 2022, when Eurorack had long since moved past its niche hobbyist roots and into professional studios, live rigs, and hybrid production setups. As modular systems grew in complexity, so did the headaches of integrating them with conventional audio gear. While many manufacturers focused on new oscillators, filters, or sequencers, ADDAC went after a quieter need: reliable, noise-free output. The 710 fits into their 700 Series, dubbed "Analog Heritage," which includes utility modules like the 711 Balanced Inputs and 712 Vintage Pre. Competitors like Mutable Instruments or Intellijel offer output solutions, but few provide the same level of transformer-based isolation in such a compact, affordable form.

Collectibility & Value

As a relatively new module, the ADDAC 710 isn't yet a "collector's item" in the vintage sense, but it has a reputation as a reliable, no-nonsense utility piece. On the secondhand market, assembled units typically sell for between €120 and €150, depending on condition and whether they include the original packaging or documentation. DIY kits in unopened condition go for around €90 - €110. It contains no moving parts or volatile components, so failure rates are extremely low. The most common issues are mis-soldered joints on DIY builds or damaged XLR jacks from rough handling. The transformers themselves are not prone to degradation. For buyers, the main concern is making sure you're getting a genuine ADDAC board, as counterfeit Eurorack modules do circulate. The clip LEDs are a small but useful feature. If they're not lighting up, check the power connection first, as the module draws equal current from both rails. It won't appreciate like a vintage Roland, but it's a low-risk purchase if your modular needs to interface cleanly with external gear.