Head stack fixtures for securing head stack assemblies to spin stand testing systems, and spin stand testing systems incorporating such fixtures, are disclosed. Exemplary head stack fixtures comprise a base supporting a piezoelectric actuator. The base includes an attachment mechanism for securing the HSA in such a way that the HSA will pivot relative to the base. When the HSA is secured to the base, the piezoelectric actuator engages the HSA. The piezoelectric actuator is therefore able to pivot the HSA relative to the base for fine positioning of a head of the HSA.