When I've tuned my stylophone the pitch control is around the 11 o'clock position.
I used a guitar tuner to tune my stylophone. But if you want to do it by ear or you haven't got a tuner. Play an F on another instrument and tune your stylophone until the 1 key sounds the same. If you haven't got another instrument, use an online one
www.bgfl.org/bgfl/custom/resources_ftp/c.../music/piano/sax.htm
Hope this helps
