R2R DACs are definitely in vogue, as demonstrated by the new iBasso DX270 audiophile DAP, which features a brand-new R2R Ultra architecture comprising 344 resistors for fully passive audio conversion. With Hi-Res playback up to 32-bit / 768 kHz and DSD512, 1,575 mW power, Android streaming and battery or mains power, this new portable player brings the on-the-go experience closer to that of a sedentary hi-fi system.
Passive conversion to 344 resistors
Where the majority of portable music players on the market rely on delta-sigma DACs, iBasso opts for a discrete R2R architecture, much rarer in the portable world. The principle is based on a network of resistors matched with extreme precision, forming a so-called R-2R ladder. Each bit of the digital signal is converted to analog voltage via a precise combination of these resistors. Unlike delta-sigma DACs, which rely on oversampling and modulated noise, this approach enables direct conversion, with excellent temporal coherence and no quantization noise pushed into the high frequencies.
On the iBasso DX270 DAP, this architecture is taken to the extreme with a fully symmetrical 8-channel configuration, based on a total network of around 344 very low-tolerance resistors, selected and matched to guarantee optimum linearity. The architecture is hybrid, combining a 20-bit R2R DAC for the main conversion and a 4-bit “String” DAC dedicated to the most significant bits. The whole system is driven by a proprietary FPGA controller, responsible for digital flow management, jitter reduction and, above all, real-time calibration of the resistor network. This ensures optimum playback of music at up to 32 bit / 768 kHz and DSD512.
Amplification worthy of a sedentary system
The other great strength of the DX270 lies in its amplification section, worthy of a true desktop headphone amplifier. iBasso adopts a fully symmetrical architecture here, from the R2R DAC to the outputs, with independent stages per channel to maximize signal separation and stability. With the balanced 4.4 mm output, it delivers up to 1050 mW per channel into 32 ohms on battery power, and up to 1575 mW per channel into 32 ohms when powered via an external 12 V source in Super Gain mode. Maximum output voltage reaches 7.3 Vrms, enabling it to drive high-impedance headphones (up to 300 ohms and beyond) and particularly current-hungry planar transducers without difficulty. The 3.5 mm unbalanced output also remains very solid, with a power rating of up to 416 mW into 32 ohms.
Designed as a truly versatile source, the iBasso DX270 DAP offers a wide range of connectivity options, covering both portable and sedentary uses. In addition to its headphone outputs, it offers a 4.4 mm line output, as well as the option of configuring the 3.5 mm jack output for line level or coaxial output. This means it can be integrated as a source or streamer into an existing hi-fi system. At home, its included 12 V AC adapter optimizes performance while saving battery power.
Android 13 with streaming services
As for the interface, the iBasso DX270 audiophile DAP adopts a particularly relevant dual approach. On the one hand, Android 13 provides access to all streaming apps, from Qobuz to Tidal and Spotify. On the other, the proprietary Mango OS system offers minimalist audio playback, with no superfluous processing to guarantee bit-perfect playback. In both cases, the player is easily controlled from its large 5.5″ touchscreen with 2160 x 1080 pixel resolution. The battery offers up to 13.5 hours of autonomy, so you can enjoy your music comfortably all day long.
Now available on Son-Vidéo.com for €1,149, the iBasso DX270 DAP stands out as much for its R2R architecture as for its overall approach to sound reproduction. More organic, denser, but also extremely high-performance from a technical point of view, it is aimed at a discerning audience in search of a different listening experience.
