Rogue Audio Sphinx V3 Integrated Amplifier / Separate Phono Preamp

I have a Rogue Audio Sphinx V3 Integrated Amplifier with a built-in phone amp.  I'm having an emotional desire to upgrade to a separate phono preamp based on  Paul McGowan, of PS Audio, recent post saying it was the most important part of an audio system..What budget do I need to have to improve what I currently have and any suggestions?