So, why would you buy the more expensive microZOTL Preamplifier over the MZ3?
The dedicated microZOTL Preamplifier has more inputs, a tape monitor section, balanced XLR inputs, and is in a standard rack-ready chassis.
Full disclosure: the headphone circuit in both the MZ3 and the microZOTL Preamplifier are identical as well.
Small and mighty. The highest expression of the patented microZOTL technology as a headphone amplifier, a preamplifier, and integrated amplifier in a desktop-sized package.