Graham,

Yes, the Master EQ was the first thing I tried after installing the OS. I mostly play through the built-in speakers and the default sound was to bass heavy and a little dull in my opinion. Now I can get it just right with the Master EQ. The speakers now sound much better with improved separation of the individual instruments.

One thing to note is that the polyphony drops from 120 to 118 when you use the Master EQ. No one would probably have noticed this but it tells something about Korgs attention to detail that they actually document this in the manual.

Kind regards,
Tommy