I was looking for a cheap mic preamp so I don't have to pack up the Motu and travel with it, and I also wanted it to have an optical output and be USB bus powered. Cheapest I could find was the Tascam US-366.
It's only down about 1.5db at 5hz compared to the Motu Ultralite AVB:
Only downside is that the max mic input level is -6dBu. That's fine for sweeps but not enough for GTG-level type of SPL levels.
I have a few XLR attenuators I could use if I need more input headroom though.