Hi Graham,
maybe not, I came across a brand of sd card the other day that won't work with audio files in the kn7 using the Panasonic Audio Sd Writing Kit Software (Juke Box). It works perfectly well with the Panasonic Card Reader and KN7 for saving midifiles, songs & styles etc but will NOT work with audio.

best wishes
Rikki

p.s. It is definitely an sd card not a mmc card.