thanks, I was hoping ur44 have proper HiZ input (1Mohm), but its not specified officially in manual...I will try to contact support for answer. 500Ohm is not proper HiZ.
The HiZ is 1Mohm. The original getting started manual contained incorrect information and an errata document quoted the correct values.
Check out the following post where I have listed the full details of the UR44 inputs/outputs/sample rates etc