I am the original owner of this Mutec and have had great success feeding it from first, a mRendu, then a SOtM 200Ultra. In both cases I had the MC3 clocked by either a MutecREF-10 or SOtM Master clock.
From the Mutec website: The MC-3+ Smart Clock USB is setting a new benchmark for clocking technology and the reproduction of digital audio by uniquely combining an audiophile USB interface with an audio re-clocker in perfection! Particularly designed for the demands of high-end consumer audio, the device expands a new sonic universe with increased musicality, clarity, and precision.
Price includes PayPal fees and shipping. Sales only to US. Can be returned within the first 24 hours if not as described in the product ad. Buyer pays return shipping and insurance.