ADDAC System - 711 Balanced Inputs

ADDAC711 is a dual channel Isolated DI box and is all about keeping the sound coming into your Modular free from any undesired noisy interferences, making sure that what you’re getting from your inputs is what your external hardware is actually producing. It provides galvanic electrical isolation between the Modular system and external sources preventing impedance mismatch and ground loop induced hum.

ADDAC’s 711 circuit is designed around a unity 1:1 type Audio Transformer operating in the 20 Hz to 20 kHz range, this impedance matching transformer provides two fully balanced outputs (via XLR connectors).

The LIFT/FLOAT/GND 3-way switch lets you choose between lift, ground or floating ground.
In the LIFT position (left) the module circuit will be “lifted” to ground through a 100R resistor and a 10nF capacitor.
In the FLOAT position (middle) Ground will not be shared leaving ins and outs grounds completely apart from each other fully isolating both signals.
in the GND position (right) Ground will be shared between inputs and outputs, here no isolation is used.

Any of these three positions may be the best form of avoiding ground loops or any other undesired interference occurring between your modular and the external hard- ware. Try out which one of these options will work best in any given situation.

DIY-Kit-Type:
SMD-Kit-1. This is a Do-It-Yourself kit, not an assembled module. The kit includes all parts to build the module. All SMD parts are pre-soldered, only trough-hole parts to solder. For build guide, more info, videos etc. please check the buttons below.