Damping factor has very little to do with bass output. My ksa 300s has a damping factor of 150 and has great bass. It's the size of the power supply that matters most. I doubt you will find anything with a power supply as large as those krell amps.
Lowend amp
Have had Krell Ksa 250 and 300S as Well as Ksa200.
Love the lowend control for B&w speakers.
Now these things are older wondering what amps have similar lowend control that are Very reasonably priced?