Thank for all the help from the list.
As people suggested, I set knob 1 to control midi# 7. Doing that enabled me to control the volume of my Vintage Keys with the AN1X. Then I turned the Local off. I could hear the Vintage Keys. The AN1X was silent. Then I turned the volume of the Vintage Keys all the way down, using knob 1 and turned the Local on. Now I can hear the AN1X and the Vintage Keys is silent.
Thank you, everyone.
Jimmy