John Darko
FiiO has announced an R2R version of its K11 DAC / headphone amplifier. Ditching the Cirrus Logic silicon of its Delta-Sigma sibling, the K11 R2R uses a 24-bit R2R resistor array to decode the digital audio signals arriving at its three digital inputs: USB-C, TOSLINK and coaxial. A pair of RCA sockets connect the K11 R2R to an external amplifier.
Why R2R? Many audiophiles favour the (often) richer and/or more rhythmically alert presentation of R2R designs despite their propensity not to measure as tidily as delta-sigma circuits.
From the promotional materials “[The K11 R2R] consists of 48 resistors per channel, a total of 192 high-precision ultra-thin film resistors with 0.1% accuracy and low-temperature drift between the four channels.” Date rate compatibility tops out at 32bit/384kHz for PCM and DSD256 for DSD.
However, the K11 R2R isn’t entirely a non-oversampling (NOS) DAC: it features a NOS mode that bypasses any filtering for always bit-perfect playback; but according to FiiO, clicking over to the oversampling mode retrieves more detail by upsampling all incoming signals to 384kHz.
If that weren’t enough, the unit also features its own headphone amplifier with exit holes for quarter-inch single-ended and 4.4mm balanced connections. TI OPA1642 op-amps work as low-pass filters before dual SGM8262 op-amps provide up to 1.3 Watts of headphone drive. Three user-selectable gain modes cover headphones of most sensitivities. Volume level is displayed on the front-panel LCD screen.
Priced at around €160, this could be the most affordable R2R DAC on the market at the time of writing. Your choice of black or silver.
Further information: FiiO
