Hi Ken and all, >I'm looking for the circuit diagram to a precision full wave rectifier that will go up into audio frequencies. If you want a all singin' and dancin' one, my Wavefolder will do FWR and a lot more besides. www.techrepairs.freeserve.co.uk/projects.htm Regards, Tony Allgood Penrith, Cumbria, England My music: www.mp3.com/taklamakan