Is there a way to utilize the on-board effects when playing an instrument (ie: guitar) through the input jack on the Equinox, or is the input just for sampling? Nothing clear in the manual on this. Thanks!

To my knowledge you can buy the Equinox Vocal Processor. It's is an addon which allows you (in short) to apply harmonize and internal effects to a sound input (normal the voice, in your case the guitar).

Please check with your local dealer which effects will allow input from the vocal proc. I can imagine that the Pro effects won't work in them, but that is just my idea. In the WK series, you can apply any effect on the vocal proc input.

Good luck!
Joost