Audio Synthesis recently introduced a new version of their Passion passive preamp called the Passion Ultimate. It is fully remote controlled (no knobs or buttons), has 3 inputs plus a direct, adjusts the volume in 60-1dB steps, adjusts the balance +/- 15dB, and has a mute! I bought one a few months ago and think it is one of the best purchases I have made in years! I can't say enough positive things about it! Great for high efficiency systems that can't tolerate noisy preamps! Input impedance is 10Kohms.