NAD PP2E with Burson V5i Dual

I have NAD PP2E, factory sound is not bad but I want wider scene and voice clarity... I first change power supply for a Linear Low noise = signal is clean et punchy...but not what I want...I change capacitors with Panasonic FC and Elna, sound is really better...but lacking voice! I try to change NE5532 by OPA 2134, Better but not really better :) I try to put Burson 5VI with a SMD to DIP-8 socket... and I hear voice !!! 5VI is really clean, clear and transparent! A bit to bright but I guess time make it smoother...