Hi JM.
These are units that are not commonly discussed here, never mind listened to. I reviewed the literature without looking for pricing. They are both tube LCR phono stages. The main difference is the Phasemation has balanced inputs and the Thrax does not. On the other hand the Thrax has balanced outputs. The Thrax has a little more gain. This would be a plus if you are using cartridges with an output of 0.2 mv or less. My inclination would be to go with the Thrax. I think the Phasmation is overbuilt and that three chassis is totally unnecessary. Balanced outputs allow you to keep the turntable and phono stage as far away from the rest of the equipment as you want without ill effect and eliminates interconnects as a factor. Most preamps now have balanced inputs. Very few tonearms come wired with XLRs. The Thrax, IMHO, is a more intelligent design. It's build quality is also first class all the way.