As a former owner of the Khorns for some 23 years, I can say that I have listened to them with several amps. Those who say SS is not a good choice are spot on. IMO, vintage type low wattage tube amps are the way to go. A few amps I owned that sounded fabulous with these speakers were;
Baldwin -converted organ amp by Will Vincent. 25 wpc
Custom made OTL 6wpc (made in Italy by Mario Patrizio-unbelievable bass!)
Art Audio PX25 6wpc (midrange magic)
A few that I didn't care for were;
Audio Research Classic 60 (too bright and fatiguing)
Cary 808 Rocket 88 (no bass or dynamics-boring)
Cary CAD-300se (as above)
A couple that I never heard, but read from others that sound good with the Khorns;
McIntosh MC225 or MC240
Quicksilver Horn Monos
My opinions are based on listening to mostly classic rock music.
Lastly, you might want to go over to the Klipsch forums where you will read about anything you'll ever want to know.
Baldwin -converted organ amp by Will Vincent. 25 wpc
Custom made OTL 6wpc (made in Italy by Mario Patrizio-unbelievable bass!)
Art Audio PX25 6wpc (midrange magic)
A few that I didn't care for were;
Audio Research Classic 60 (too bright and fatiguing)
Cary 808 Rocket 88 (no bass or dynamics-boring)
Cary CAD-300se (as above)
A couple that I never heard, but read from others that sound good with the Khorns;
McIntosh MC225 or MC240
Quicksilver Horn Monos
My opinions are based on listening to mostly classic rock music.
Lastly, you might want to go over to the Klipsch forums where you will read about anything you'll ever want to know.