One way to look at the Stereo 50 is as the combination of an iFi Micro iDSD headphone amp/DAC, an iFi Micro iPhono phonstage, and a 25Wpc valve driven power amp—an appealing combination to say the least.
Complementing the Stereo 50 are a pair iFi-designed RETRO LS3.5 mini-monitors. You guessed it: iFi describes the LS3.5 as a “21st century take on the legendary BBC LS3.5a”. The tiny monitor’s cabinet is, like the cabinet for the Stereo 50 amp, made of laminated bamboo, which iFi says is two times lighter and three times stronger than conventional MDF/wood cabinet materials. The speaker uses two iFi designed and manufactured drivers: a 4.5-inch paper cone mid/bass driver and a 1.1-inch, waveguide-loaded, silk dome tweeter. The larger driver is allowed to run full range (59Hz to 8kHz) above which point the tweeter rolls in, using a simple, minimalist first order crossover. This arrangement, along with the tweeter’s waveguide, which sets the tweeter’s diaphragm back a bit from the speakers baffle is said to provide nearly ideal phase/impulse response, while ensuring that all fundamentals and formants (save for bass fundamentals that fall below the speaker’s low-frequency roll-off point) are handled by the 4.5-inch mid-bass driver.
The cabinet itself is a so-called ‘multi-chamber Voigt design” with a rear firing, slot loaded port that iFi calls a ‘transmission line’. The interior of the cabinet features multiple braces that are patterned after the braces used in some musical instruments (most notably, the braces use to support the tops and backs of some acoustic guitars). The interior of the cabinet features ‘minimal internal damping’, but the damping that is used comes courtesy of ‘advanced Amino-plastic open cell foam’. This material is said to offer good absorption, but still allows ‘the deepest and cleanest bass’ along with a wide-open midrange.
The total price of the system in the US is $1999.