Inspired by the legacy designs of premium vintage gear, the ADDAC800X behaves like a high-quality DI box and is all about keeping the sound coming from your Modular free from any undesired noisy interferences, making sure that what you’re getting from your outputs is what your Modular 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 800X circuit is designed around a unity 1:1 type nickel core Hammond Audio Transformer from the 140UEX series (equivalent to Jensen audio transformers).
Operating in the 20 Hz to 20 KHz range and providing exceptional shielding from external sources, this impedance matching transformer provides the 800X with two fully balanced high-end outputs (via XLR connectors).
The importance of using Audio Transformers
Applying a transformer balanced output isolation has lots of advantages over other less expensive ways for dealing with ground loop issues. This method provides the chance to set a very simple and clean circuit in which the signal transfer process develops smoothly and humming free. The transformer is a device that performs both signal balancing and high-to-low (or vice-versa) impedance conversion, while rejecting straggled DC voltage and Radio Frequency Interference from signal passing through a magnetic bridge. In a transformer, two (or more) coils (called windings) of insulated wire wound around a magnetic metal core allow for its input(s) and output(s) not to be physically connected together. When an AC signal passes through the input winding (the primary), a perfectly related AC signal appears on the output winding (the secondary). This way, by the fact that signal flows via inductive coupling between the two windings of the transformer, the ADDAC 800X presents a most accurate electrical isolation between its input and output. A same number of windings on each coil guarantees that there’s no gain loss when audio signal passes from the primary to the secondary windings. Furthermore, since these two windings are insulated from each other, the transformer will electrically isolate the 800X from any other device, preventing hum problems coming from an outside ground.
- 100 mA +12V
- 100 mA -12V