I was really busy in the lab yesterday so I just sent out your link. Let us know if you have any issues.
Regarding the two volume controls – The Digital Power Station slider represents the sound going INTO the DPS processing. The other slider represents the sound coming OUT of DPS processing and going to your speakers.
Usually your keyboard volume will only change Digital Power Station. But you can adjust either slider for good effect. Notice how the sound is slightly different when you turn down one or the other.