I would give the Origin DCX Bass a look as an alternative to the Noble. @IvanBassist recently substituted the DCX for his Noble on his live rig. The DCX sounds much better than the HX's Noble model, IMHO.
I had one when it first came out and it is a great preamp. I wish it had a XLR/DI out, so for me it really isn't a substitute for a tube DI/preamp