Mellotronists

I had a chance to play with a Motion Sound pro-3x amp.  It has a real
rotary horn (above 800 Hz) and a bass rotor simulator mix.  Good dual
rotor sound, nice size and price too.  (6.5"H  20"W  16.5"D  27lbs, $700)

http://www.motion-sound.com/rotary_amps.htm