I suddenly got a flashback from middle school .....
anyway, to answer your question about controling speeds, if you go to Best Buy and purchase a Unversal AC Adapter you can control the speeds. The device plugs into the wall, and has several different accesories that can work on nearly all MP3s, CD Players, Cordless Phones, ect. Just cut off the end and attach it like you would with a phone charger. The device (being that it is universal) usually has several different voltage settings (12v, 9v, 6v, 3v, 1.5v, and off). Set it to 12v for full power, or dial it down as needed. Hope that helps.