If the receiver has preamp out/ amp in connections it will work fine. Remove the jumper and connect your preamp to the amp in connections and you are good to go. You will have bypassed the preamp in the receiver.
Agree with Wendell; not all receivers have a pre-out amp-in connection (my old NADs did), so check the back. However, I would not necessarily equate more watts with better sound. What are your speakers (are they hard or easy to drive, what is their nominal impedance), and what is the amp you're using instead of the Pioneer? You may not need the extra watts, and depending on the power ratings of the Pioneer into the load presented by your speakers, the difference in WPC might not be as large as you think. It's worth listening to your present amp and the Pioneer into your speakers to see which you like better.