TC Helicon VoiceTone C1 Product Overview by GAK The TC Helicon VoiceTone C1 allows you to control your sound from subtle pitch correction to striking HardTune and even gender manipulation for otherworldly vocal sounds. The C1 provides simplistic guidance of pitch correction with key, chromatic or guitar input and you can determine the level of your attack with the user-friendly interface dials. The VoiceTone C1 is enclosed in a study, roadworthy metal case and inside you'll find a clean, quiet mic preamp which even challenges high-end touring mixers and studio quality analog to digital conversion. There's also a USB connection for firmware updates. The C1 is also completely controllable via your microphone. Plug in an MP-75 mic or the Sennheiser e835 FX and you can turn on your effects with the push of a button.