Quickly and easily add an awesome variety of effects to your vocals with the Roland AIRA Compact E-4 Voice Tweaker. This ultraportable effect unit harmonizes, auto-pitches, vocodes, loops, and rhythmically glitches your voice (or any other audio source you feed into it) using intuitive button and fader controls that you can manipulate both for live performances and studio recordings. Plug a microphone into the 1/4" input and use the level control to set the right gain for your voice; the 3.5mm headphone jack can also accept an inline headset mic. Then simply dial in the effect you want using the front panel controls. MIDI ports, sync I/O, and a class-compliant USB interface allow the E-4 to play nicely with DAWs, mobile devices, and, of course, other AIRA gear. The unit is powered via its USB port, which also charges the built-in lithium-ion battery. The battery allows the E-4 to operate for up to 3.5 hours on a single charge.