I/55

Audio Research I/55 is a compact tube integrated amplifier derived from I/70, succeeding I/50, targeting high-end listeners seeking classic tube sound with modern connectivity.

Fully tube-based amplification uses matched pairs of 6550 output tubes and 6922 input/driver tubes, adding Auto-Bias for continuous idle-current control without manual adjustment.

Rated at 2 × 50 W, the upgraded tube preamp offers wider gain range, stronger dynamics, Pre-Out outputs, and improved control with demanding loudspeakers.