Hello, this description makes no sense to me. "I am using an array size of 512 or 1024 channels to address a line speed of 10-2-mhz with individual channel logic of 48Khz with an AM envelope." Particularly the 10-2-millihertz part. Could you make another try at explaining what you need?
As to the second sentence, it is impossible. You will always introduce some distortion at the moment of switching, unless you have an extremely complex switcher.
Example: If you have a very strong oscillator outputing some frequency signal. Let's say pure sinewave. And it is feeding a purely resistive load. If you switch the output to a different, but otherwise identical load, during the switching period you will introduce distortion onto the output of the oscillator. Now, if this is not a problem, then maybe I can help if I better understand what you are trying to do.