I think both. If the preamp is not resolving enough, the resolution of the phono stage will not make its way through. I upgraded a few years ago from a AyreK5xe MP Preamp to a Jeff Rowland Criterion and the sonic improvement was staggering. I just upgraded my phono stage from an Asthetix Rhea to an Allnic H3000 and, once again, the improvement is staggering. I wouldn't hear the improvement that I do from the Allnic through the Ayre.