Hi Spalding
Yes you can change the Acoustic Bass of a Korg style (Or any normal voice) with a better quality Acoustic Bass voice from a VSTi, however you can�t just substitute and ordinary Acoustic Bass (No matter how high the quality) for a Mega Voice Acoustic Bass, as the voice you choose has to have a similar set-up to the Mega Voice.

Most people think Mega Voices are just ordinary voices with a few extras added, however they are NOT, they are specifically engineered for style play on Yamaha instruments. (This is why (Just like SA Voices) you don�t see many Mega Voices released, whereas ordinary voices are aplenty)

Bill