Jorge, any receiver that has a "sound" is either designed incorrectly or is defective. Modern receivers amplify transparently without adding a sonic coloration of their own.
All modern receivers have far more than sufficient inter-channel separation. If you have some type of separation problem it has nothing to do with the receiver(if you have the settings correct), but instead either relates to the source material or the setup of your listening room(compared to the one at your friend's house).
The 3310 is an excellent receiver, but neither it nor any other amplifier will make any difference in the "big ball of sound".
