As someone who likes to do synthesis on the Octatrack, I sometimes get frustrated by the two-octave limit when working with single-cycle waveforms, so I’ve made a little tool to help. It’s called OctaCycle and you can use it for free in your web browser.
Just press Import…, navigate to a folder containing any number of wave files (e.g. the AKWF set), and click Save .zip. The files will be resampled into sample chains, spanning 7 octaves by default. You can adjust the starting note and range to your liking, as well as the cents offset (±100). Additionally you can change how the resulting files are named. Note: Your samples are processed entirely in-browser, though your browser may use the word “upload” when you import them.
OctaCycle is currently in alpha. I’ve been using it but my testing is pretty limited, and bug reports are welcome.