Just a quick tip for windows users, you can use waveosaur to do some single cycle waveforms, its freeware and actually pretty cool -
http://www.wavosaur.com/You can create a sample using >tools>synthesis>simple then select from various wave types and then add, mix etc others, its pretty cool and with vst support you can add some fx etc, have fun and experiment with it.
Also audacity (multi platform) can do similar stuff.
Remember to just use single cycle for best results (ie 1 complete wave period)