I do have 4 other cables that work, but I don't like them for different reasons. None of them have that additional little collar like the stock ones. There is also (I looked) no matching recess around the jack on the HP50 for that collar.
This is one example:
They do work, but I wanted something longer.
The problem I have seen with connectors like the Neutrik in your photo is that the will not fully seat because the body of the plug does not fit into the recess far enough.
I hope they do work, it will give us another option, and an inexpensive one at that.
I got a shipment notification, so we will see pretty soon.
that could very well be the reason the Neutrik did not fit. Good Luck and let us know the outcome.