I had an Adcom preamp and Adcom amp (7500 also) combination before. I switched to a Sunfire preamp and Sunfire amp combination. I'm happier with the Sunfire vice the Adcom. The Adcom seemed to lack in overall strength/authority (amp) and my system sounded thin. The Sunfire is definately warmer and stronger sounding.
My speakers were and still are Klipsch Legends (horns) so they tend to be on the bright side. To get the mids and highs under control (at least for my system), NBS cables were the miracle answer. The mids were transformed and the highs were much more tolerable.
As others have noted, the source is important. I just switched from a modified Music Hall CD-25 to an EAD cdp. The sound again improved becoming smoother and much, much more analog sounding.
IMHO, NBS cables and the source would be a great start for you.
Mike