Small inexpensive transformers will still do the trick when it comes to balancing the signal and providing isolation, but their performance suffers when it comes to frequency response, noise and distortion levels, and they tend to color the audio even at low signal levels. The quality of the transformer used in a passive direct box is usually directly related to the cost of the device itself. Speaking of transformers, not all of them are created equally. As an added benefit, these transformers will also block the transmission of 48V phantom power, protecting your keyboardвЂ™s output stage from damage should phantom power be accidentally engaged at the PA. Transformers like those found in the Radial ProD2 provide galvanic isolation between your source and destination devices, effectively preventing ground loops from occurring. The surest solution for breaking up a ground loop is to insert an isolation transformer in the signal path between the two devices, and this type of transformer just happens to be at the heart of every passive direct box. Ground loops can occur when directly connecting two distant powered devices (for example, your keyboard and the PA mixer). A direct box solves this problem by providing a balanced XLR output that allows you to send the audio over distances of up to 300 feet without signal degradation.ДЄnother reason to utilize a direct box with your keyboard is to avoid the dreaded ground loop, which can cause annoying and possibly show-stopping hum and buzz through the PA. While unbalanced signals work just fine over short distances, once long cables are employed they are more susceptible to noise and interference, as well as high frequency signal loss. There are a few reasons for this: the first one being that the outputs of most keyboards are unbalanced signals provided over 1/4вЂі TS connectors.

Whether you have a straightforward setup with a single keyboard, or if you utilize multiple instruments including MIDI controllers and soft-synths, choosing the right device for your rig can help improve your audio signal quality, reduce noise, and provide you with greater control over your tone through the PA system.ДЇor the simplest of setups that employ a single keyboard on stage, a high-quality passive direct box is the most commonly recommended device for connection to the PA. While itвЂ™s true that most keyboards have low impedance outputs that can connect directly to the line inputs on a mixer (so long as those inputs have sufficient gain), there are several benefits that are provided by using a direct box or a dedicated keyboard interface on stage. One of the most common questions we are asked by keyboard players is what equipment they need to connect their instrument to the PA.

Piano keyboard connect to computer