In my experience with the Korg (2)PA800, (2) PA500s, (1)PA60 the settings I had to use on my EMX 312SC then EMX512Sc, versus the Tyros 2,3(4 now) keyboards I had then and now, are basically a mirror of what Victor describes, I had the Yamaha at "noon" and the Korgs I had to Max the volume to more or less even the volumes when I played with those 2 arrangers.

I have not try yet the outputs on my latest acquisition, the Micro-Arranger.