The beloved Stylophone has done a lot of growing up lately. Last year's Gen X-2 brought CV/gate connectivity to the stylus-operated synth, and the Stylophone Voice, unveiled at NAMM in January, turned it into a pocket sampler. Its latest iteration, however, heads firmly in the other direction. Stylophone Mini is a miniature take on the original Stylophone, first introduced in 1968, and it's designed to be carried around with your keys or clipped…