T.C. Helicon is a studio quality voice processor. This machine is a rack mount type, and can create instant 4 part harmony, pitch correction, eq., compression, built in pre-amp, effects and more! anyone who is familiar with pro audio equipment, knows that T. C. Helicon is hi-end stuff. I bought it on e-bay about 4 years ago, paid 450.00 for it and it hasn't been used much. I would like to get 400.00 for it, so if you're serious, please call 731 676 2097.