which preamp for my cary slam-100 mono's?

Cary SLP-98F1

I second the Cary SLP-98F1 direct coupled.

I have a CAT SL-1 mk3 w/phono with the slams and have been completely happy with the combination for years (+ the CAT has never had a single issue in over 10 years of heavy use)

I should add: I auditioned the SLP-98 (whichever version it was 10 years ago) and liked it, but the CAT is more neutral, which is important to me because I listen to a very eclectic mix, from joni mitchell to electronic/experimental. if I mostly listened to singer/songwriter or small ensemble jazz or chamber music, the Cary might have been my choice.

(at the other extreme, among preamps I tried, was spectral - way too 'detailed, etched, analytical' for me!)

CAry SLP98 F1, another vote.