In order to hear only the sample without the Instrument attributes, you have to go to the Samples page and click on the icon which does so. In order to hear a sample with its Instrument attributes, you have to go to the Instruments page and click on THAT icon.

Many times i'm editing an Instrument in which i'd like to hear the sample raw, to figure out the best edit in the Instrument "casing." Other times i've set up the Instrument with a sample, but want to go back and edit or change out a sample, and hear how the Instrument settings affect it.

What would then help greatly is the Sample Preview and Instrument Preview buttons as a redundant feature on the Main Toolbar.

POSSIBLE ISSUE: I'm way ahead of you: what if you have a sample assigned to multiple Instruments -- which Instrument would be played if you pressed the Instrument Preview while on the Samples page? Simple; the current, most recent, or first Instrument (in that order) that was edited that held that sample. Same with the Sample Preview on the main Toolbar when in the Instruments page (not just the sample mapped at C-5).