When we developed our MIX-BX mixer we decided to design a premium quality headphone amp for it.
Most mixers or output modules have a flimsy one opamp headphone amp with very limited drive capability and most of them cant drive low impedances without running out of steam and sounding distorted.
So our MIX-BX headphone amp is a high quality complementary transistor based amp capable to drive almost any headphone impedance to high enough SPL with good dynamic range and very low distortion.

So what all the mumbo jumbo from above has to do with our new PHONEZ module?
You get exactly the same premium quality headphone amp as an independent module.