Mcintosh c-28 Where do i go from here?

Hello fellow 'Goners. I have been listening to my recapped Mcintosh C-28 for some time now and find it pleasant to listen to but I believe that I am still missing out from newer 2 channel preamplifiers. Although the c-28 has a pleasant sonic signature, it can sound a tad too dry, clinical and edgy especially during long acoustic (guitar) passages (William Ackerson's in search of the turtle's navel comes to mind).

I know that my c-28 has impressive resale on the pre-owned market (around $600). What would I replace this preamp with? What are your thoughts? As an FYI, I am not willing to spend over $600. My other components consist of a Mcintosh MC-2155, CAL Genesis cd player, and dali suite 1.7's.

Thanks in advance.