Some relatively affordable tube CDP's options: Audio Aero Prima, Shanling CDT100, Super Tjoeb, Jolida 100A, Heart 6000 OSE LE, Cary. Not sure if all of these would best your Cairn Fog.
Another route to consider... a NONOS design DAC (unfiltered, no oversampling) coupled with an affordable transport or quiet pc hard-drive (possibly SACD so that you have the best of both worlds). These DAC's include 47 Labs Shigaraki, Audio Note, Ack! Dac, Scott Nixon, etc) or a NONOS CDP such as Audio Note. Sound is supposed to be natural, linear with good PRaT and an absence of digital glare.