The Audio Research I/70 integrated amplifier distills the performance of the company’s acclaimed separates into a single, elegantly proportioned chassis. Its visual design borrows directly from the Reference 330M monoblock, with anodized top and bottom plinths, a fully enclosed transformer array, and machined aluminum mesh that signals serious engineering intent. Inside, the same output transformer found in the Reference 75 amplifier works alongside four KT120 output tubes to deliver 70 watts per channel, imbuing the presentation with dynamic swing, control, and resolution that feel unexpected at this price point. Auto-bias circuitry maintains optimal tube performance without user intervention, while a 75-step volume control and a wide range of gain settings accommodate recordings cut at low levels for broad dynamic range.
Connectivity is comprehensive, with three single-ended inputs, one balanced XLR input, and an optional phono card offering adjustable MC loading and MM gain. The built-in DAC, centered on an AKM Velvet Sound chip, handles high-resolution formats via USB, optical, coaxial, and Bluetooth—all upsampled for fine resolution and tonal purity. A dedicated headphone output driven by the KT120 output tubes provides a direct, high-quality personal listening path, and the independent preamplifier section includes stereo outputs ideal for feeding powered subwoofers. Hand-built in Audio Research’s Minnesota facility and individually auditioned, the I/70 brings the authority and musical engagement of the company’s larger separates into a compact, versatile integrated form.