Integrated Amp Reviews

The first true high-end component I owned was an Audio Research SP-10. I reviewed this two-box, tubed preamplifier in the May 1984 issue of the English magazine Hi-Fi News & Record Review. "The SP-10 presented [recorded] information in a more coherent, less distorted manner than any preamp I've tried," I wrote in the review, concluding that "the SP-10 made me realize how many good records I owned." I purchased the SP-10 and brought the preamplifier with me when I moved to the US. Four decades later, I still have that SP-10. "Every now and again, when I want to be reminded of the magic it brings to my music, I set it up, plug in the tubes, and spend an evening spoiling my ears," I wrote for an article in Ken Kessler's 2020 book on the history of Audio Research.

I was planning to review the latest product from Audio Research, the I/50 integrated amplifier, which costs $5500, earlier this year. However, with the uncertainty back then about the company's ownership, I postponed the review. When the news broke in June that Audio Research had been acquired by AR Tube Audio Corporation, a privately owned corporation that includes Valerio Cora of Canadian loudspeaker manufacturer Acora Acoustics as a director—see Industry Update in this issue—I unboxed the I/50 and set it up in my listening room.

It was a cold March-in-Brooklyn morning. Clouds had been shedding wintery mix since daybreak. By 9am, birds were flash-mobbing my window, demanding suet. But I was frozen—unable to pull my mind loose from the grave flowings of American composer Ned Rorem's Book of Hours, as performed by Les Connivences Sonores on the album Musikalische Perlen (24/48 FLAC, Ars Produktion/Qobuz). The sounds in my room were sensuous and mesmerizing, and I needed to float in their mysterious energy as long as I could.

I was listening through the most compelling sound system I had assembled since I started writing for Stereophile. The dCS Bartók DAC/streamer was funneling the harmonic purity and hypnomagik of Odile Renault on flute and Elodie Reibaud on harp into HoloAudio's appropriately named Serene preamp, which was feeding Elekit's TU-8900 300B/2A3 kit amplifier, which was sending a few of its triode-tube watts to the TAD's $32,500/pair Compact Evolution One monitors, more compactly known as the TAD CE1TX.

Back in the 1950s, Cesare Sanavio, then a new electronics graduate with a specialty in output transformers for tube amplifiers, began his career in radio and television, traveling to various locations outside his native Italy to apply his expertise. Eventually he settled in Paraguay and started designing tubed sound systems for public installations, teaching his son Luciano the art. A few years later, Sanavio and his family returned to Italy. There, he worked as a consultant to several hi-fi companies. Finally, in 1994, drawing on decades of accumulated knowledge of tube-amplifier design and manufacturing, and a particular focus on output transformers of the highest quality, Cesare Sanavio and his two sons, Luciano and Lorenzo, formed Mastersound.

When Cesare Sanavio died, Lorenzo and Luciano continued operations. In 2015, the company re-formed, with some new international business connections and a new CEO, Antonio Ferro.