http://www.datasheetcatalog.org/datasheet/PrincetonTechnologyCorporation/mXyzsyzt.pdf Build an experimental echo pedal http://blog.makezine.com/archive/2009/10/build_an_experimental_echo_pedal.html?CMP=OTC-0D6B48984890 2009-10-01 http://makezine.com/images/logos/rss_icon.jpg