Pocket-sized USB-C DAC and headphone amplifier with K2HD technology
The iFi Audio GO bar Kensei is the flagship of the GO bar range: a DAC and headphone amplifier the size of a USB stick (65 x 22 x 13.2 mm, 65.5 g), with a body made of Japanese stainless steel chosen for its rigidity. It plugs into the USB-C port of a smartphone, tablet or computer and works straight away, with no drivers to install, delivering up to 477 mW into 32 Ω from its balanced output.
The name comes from the Japanese title of "sword saint", reserved for the few masters who stand above all others. The link with Japan is not just cosmetic: the Kensei includes JVCKENWOOD's K2HD processing, developed together with the Japanese manufacturer over 18 months of work.
K2HD, four digital filters and analogue corrections
K2 technology was created at Victor Studio to give digital recordings back the natural harmonics of the original master. In its K2HD version it extends the response beyond 22 kHz and gives music a more organic character. It is joined by four digital filters: Bit-Perfect, natural in tone and suited to every genre; GTO, which adds detail and density and works well with vocals; Minimum Phase, warmer, for soul and jazz; Standard, tighter and more controlled in the highs, for pop and film soundtracks.
Two fully analogue circuits complete the adjustments: XBass+ reinforces the low end, XSpace widens the soundstage and removes the "inside the head" effect of headphone listening. Both corrections work on the analogue signal, with no digital processing.
Cirrus Logic chipset, 16-core XMOS and hi-res formats
The digital section uses a 32-bit Cirrus Logic DAC chipset, managed by a 16-core XMOS microcontroller programmed by iFi, and a GMT (Global Master Timing) precision clock that keeps jitter very low. The GO bar Kensei plays PCM up to 32-bit/384 kHz, native DSD up to DSD256 and DXD at 352.8 and 384 kHz, with full MQA decoding.
The stated frequency response runs from 20 Hz to 70 kHz (-3 dB), dynamic range is 108 dB(A) on the balanced output and 109 dB(A) on the S-Balanced one, and THD+N on the balanced output stays within 0.0025% (2 V into 600 Ω). The amplifier stage uses an OV series op-amp built to iFi's specification.
4.4 mm balanced and 3.5 mm S-Balanced outputs
The USB-C input is at one end, the two headphone outputs at the other. The 4.4 mm balanced output delivers 477 mW into 32 Ω and 7.2 V into 600 Ω; the 3.5 mm S-Balanced output reaches 300 mW into 32 Ω and 3.8 V into 600 Ω and, with ordinary single-ended headphones, halves crosstalk and noise compared with a conventional output.
For the most sensitive in-ear monitors there is iEMatch, which adapts the output level and removes background hiss without altering the sound; for hard-to-drive headphones, Turbo mode adds 6 dB of gain. The box includes a USB-C to USB-A adapter and a USB-C OTG cable.
