4 Years ago, Yamaha has integrated his XG-concept into the PSR-series. That means you have the same sounds and effects like on a normal level 1 XG-device. There you have 3 DSP's available for digital effects:
Reverb, Chorus, Variation
Reverb adds simple reverb effects to your sound, like the ambience of a concert hall and so on...
The Chorus contains several chorus and flanger effects. The Chorus is a stereo effect which makes your sound more "fat".
The Flanger adds a kind of "soaring" effect, you could compare this to the turbine of a jet. The Cheleste effect is another Chorus variation.
Now the Variation DSP's contains all the effects of the Chorus DSP and some additional special FX, like "Telephone" or Delay...just try them out.
I hope that helps you,
webmaster of the soundpool (www.thesoundpool.de