Hi Dave
I'm very glad I stuck with the Pa600 and bought the VLT2, judging from your demo I would have been well upset if I had waited for the Pa900. I can't believe Korg have got it so wrong.
Have you tried using the VLT2 directly into the Pa900 without a mixer. I found the gain on the VLT1 was very low but the VLT2 has an extra 6db gain on the output so it should be better, I must give it a try, up to now I have been using the VLT2 into my Zoom R16 for recording.
I found using the VLT 1 directly into the Pa600 the only way to get a decent balance without a preamp/mixer was to decrease the gain on the limiter which does not affect the line/VLT input but drops the output of the keyboard.
I'll do a quick demo using the VLT2 into the Pa600 for a comparison.
Kind Regards
Col