Hard to say without knowing the rest of your system. You may want to list your components in the Virtual Systems section of your profile or list it out on this thread.
There are many better preamps than the preamp of your integrated, but the unit is no slouch. It uses Luxman’s famous LECUA 1000 volume control which is the same quality that was found in the better Luxman separates. Going with a new preamp means you’re giving up the other features of your amp, including the phono stage, but it also makes the sound more consistent between your vinyl and digital, if that is important to you. There’s no right or wrong way, but you’ll need to decide based on your priorities and tradeoffs you are most comfortable with.