Not necessarily in your case, particularly considering (as I just noticed on re-reading the question) that you already have an outboard power supply for your preamp. With that you can locate the power supply's circuitry well away from the phono circuitry. Also, does your friend's separate unit have a separate power supply for the phono, or does it have the phono and line units sharing the same power supply like you have? If the latter, it's unlikely that you will achieve any improvements from the power supply. The only other benefit from the separate phono section I can think of, of course, is the ability to substitute a different, hopefully better, phono stage for the Levinson (an IO, Lamm, Boulder?), but you've already got a pretty good unit there which is likely upgradable, and you wouldn't have to worry about compatibility issues. Just my random thoughts.