With a compact and unobtrusive design, the Presys + features volume, bass, medium and treble controls, brightness control and a notch filter (which helps to reduce Feedback: coupling filter), a phase switch and a built-in chromatic tuner With LED display. Presys preamps also include a pre-wired Fishman Sonicore electric piezo for a solder-free installation, plug and play, a low battery indicator, low profile control knobs and a unique pivot design for easy access to the Battery compartment. It also has cannon plug output.