I have to say that I have had success using the Tyros Vocal Harmonizer. As with all of these devices, certain cautions must be used. I agree with Uncle Dave. You have to control the Vocal Harmonizer, you can't let it control your voice by screaming into the Mic; It just won't handle the overload.

In LeoD's situation, he fails to mention he is using TWO Shure SM58's Y-Jacked together and input into the 1/4 mic input of the Tyros. This could have a huge impact on his results.

Al