I just upgraded from a Musical Fidelity M6 500i amplifier to a Musical Fidelity Nu-Vista 800. While the former sounds amazing and can drive just about any speaker out there, the hybrid design of the Nu-Vista 800 gives you something really special (best of both worlds tube/SS). It mates well with my PS Audio Directream DAC and Magnapan 3.7i speakers (+ two Definitive Technology Supercube I subwoofers).