Thanks Dave, looks like I did a typeo there, it's a WK3800 and it is an arranger, I was told. His issue is that he can do that but he says it just doesn't sound right. I guess he saying it sounds "cheap" through the speakers in the board, but can't hear himself in the PA when he is playing. The sound it "too dry and too thin".
I've got him playing around with the DSP's to bulk out the sound. Trying different Chorus values and Delays etc. Some sound great to me but others just don't work well at all.
Also, tried fretless bass with different effects but it's hard to see what it is adding to the sound. A better keyboard would be the answer I know that, also better set of powers speakers too.

Allan