I noticed that after a few minutes of playing my PSR3000 there is a tremolo effect on ALL the voices. It doesn't sound to bad on the piano voices, although noticeable, but the sweet saxes are horrible. If I power down and re-start, the tremolo is gone. After anywhere from two miuntes to 20 minutes, it's back. I tried a factory reset on the user effects, but there was no change.
What a disappointment.
Starkeeper