The only way to do it is to tweak the pitch. But here's the good news, there's two ways of changing the pitch.
One, and the most common one, changes the pitch by making the sample faster or slower. BUT
If you want change the pitch of the sample without changing its speed, you can do it the followng way:
Click on your sampler so the Channe Settings window comes up.
At the top of the window you have Pan, Volume and Pitch. Don't touch that Pitch knob - that's the one that changes the speed of the sample. Instead, look under the "Time Stretching" Section, about halfway down. There are three knobs - Pitch, Mul, and Time. Tweak the pitch knob and it'll change with pitch but maintain the original speed/quality of the sample. If that helped you out, please rate my track when you have the time. Peace!
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