George, I don't know if the mizmar has a vibrato: for sampling purposes it would be better without: this would allow for a much shorter loop; otherwise the loop should match the vibrato wave.
Happy sampling!
_________________________
Korg Kronos 61 and PA3X-Pro76, Roland G-70, BK7-m and Integra 7, Casio PX-5S, Fender Stratocaster with Fralin pickups, Fender Stratocaster with Kinman pickups, vintage Gibson SG standard.