I don't have the time time give a totally in depth response right now (should be working not playing with my friends :P) but the Cambridge is a budget piece whereas the Monarchy is a high end piece at a mid fi price. This has always been Monarchy's claim to fame.
The DAC from Monarchy that I've heard have all been very warm--tube like-and have killer bass slam. The midrange is liquid.
ccpoon is a diehard...