Amp or Preamp With Built-in High-Pass Filter

i was just reading about the aesthetix saturn amp and found the following:

"Amplifier has a built-in high-pass crossover: 6 dB / octave, 16 settings from 40 Hz to 200 Hz in approximate 10 Hz increments."

What other amps out there have integrated crossovers?
The B&K Ref 5 does.
I think the Emotiva audio preamp has a optional high pass filter.

Most (like that Emotiva) will be second order (12db/octave) rather than first order (6db/octave), though.