A spin-off from the well-regarded British high‑end audio company Abbingdon Music Research, in a few short years iFi has earned a reputation for building affordable, palm‑sized components whose room-filling sound belies their modest size. Given this, perhaps the last thing we might have expected would be something like the firm’s new Retro music system—a system that is thoroughly contemporary yet conceived as a fond homage to an earlier period in the evolution of high‑end audio.
At the heart of the system is the Retro Stereo 50, a full‑sized valve-powered headphone amp/integrated amp with a built‑in MM/MC phonostage, plus a high-resolution, multi‑input, PCM/DXD/DSD‑capable DAC. The Retro Stereo 50 is the first integrated amp iFi has ever offered. Apropos its name, the Retro Stereo 50 features a golden-hued faceplate whose appearance reminds us of classic Marantz integrated amps from the past. Adding to the retro theme, the Stereo 50 comes housed in an old-school-style cabinet artfully fashioned from laminated slabs of bamboo.
The Retro system also marks iFi’s entry into another new product category: namely, mini-monitor-type loudspeakers. That’s right: the Retro system comes with a pair of small, stand-mount, iFi‑designed mini-monitors called the Retro LS3.5s, which are, in spirit if not in terms of actual frequency response curves, a modern-day take on the concept of the classic BBC LS3/5a monitors of yesteryear.
The LS3.5s are a two-way design with slot-loaded, P.G.A.H. Voigt-tuned enclosures. The speaker features wide-bandwidth, 115mm, lightweight treated paper-cone mid-bass drivers that operate as full-range transducers whose output is supplemented by a 28mm silk-dome ‘super tweeter’. The enclosures of the LS3.5s are, like the case of the Retro Stereo 50, made of laminated bamboo, meaning that the Retro system’s amp and speakers make for a very handsome trio indeed. The total price of the system is $1,999 in the US or £1,650 in the UK.
The Retro Stereo 50 amplifier is based on a quartet of EL84x valves and a pair ECF82 valves and is specified to provide ‘music’ power output of ‘25W + 25W’, the majority of which, says iFi, results from Class A operation. The term ‘music power output’ indicates that iFi uses a somewhat uncommon method of measuring and rating the Retro Stereo 50’s power output. Rather that testing the amplifier as it drives load resistors on a test bench, iFi instead connects the Retro Stereo 50 to the LS3.5 speakers, plays music through the system at the highest levels possible without inducing audible distortion, then tracks the amplifier’s actual voltage swings via a recording oscilloscope. Using this data, iFi calculates an estimated power output figure for the amplifier under real-world music playback conditions. Bandwidth is an impressive 10Hz – 60kHz, while distortion—as valve-type amplifiers go—is comparatively low: < 0.2% @ 2.83v.1W.