iFi adds to its range of portable DAC/headphone amps with the hip-dac. Finished in petrol blue with a touch of copper, the hip-dac is designed to slip discretely into a pocket and offers an hi-res specification for a £149 price tag. It’s designed to replaces the DAC (digital-to-analogue convertor) and amp circuitry in smartphones, tablets, PCs and Macs and claims “to vastly improve headphone sound”.
The DAC section is based around a Burr-Brown DAC chip selected for its fluid, highly ‘musical’ sound quality and True Native architecture. This, combined with custom iFi circuitry, enables the hip-dac to deliver “excellent sound quality” across all manner of digital audio formats, including bit-perfect PCM, native DSD, and MQA – as used by Tidal’s ‘Masters’ tier. Hi-res PCM and DXD audio data is supported at sampling rates up to 384kHz, alongside DSD from 2.8MHz to 12.4MHz (DSD64, 128 and 256). Thanks to the Burr-Brown chip’s True Native design, PCM and DSD take separate pathways – this enables both PCM and DSD to remain ‘bit-perfect’ in their native form right through to analogue conversion. Coloured LEDs indicate the format and sampling rate of the digital audio being played.
Extensive clock-locking “eradicates jitter” (digital distortion), using iFi’s GMT femto-precision clocking system to maintain the integrity of the digital signal until conversion to analogue. An XMOS chip, which processes audio data received at the USB input is programmed in-house.
The hip-dac’s amp circuitry is of balanced (differential) design – unusual in a DAC/headphone amp anywhere near this price point. Balanced audio circuits have long been championed by renowned high- end audio electronics engineer John Curl, now a technical consultant for iFi, given their ability to reduce noise within the signal path. Curl has worked closely with iFi’s in-house technical team, led by Thorsten Loesch, to produce an analogue stage of exceptional quality for a device of this kind.
The circuitry incorporates a range of components carefully selected for their audio performanc, including a custom iFi OV op-amp, TDK C0G class 1 ceramic capacitors, a precision low-noise power supply IC from Texas Instruments and a high-quality analogue volume pot. The headphone amp has a nominal power rating of 400mW and is capable of delivering over 700mW from the balanced output, depending on the impedance of the attached headphones, “driving all manner of headphone/earphone types with ease”.
The amp stage features PowerMatch switchable gain. This matches the level of drive to the load presented by the headphones, by adjusting input sensitivity and thereby signal strength. With high-sensitivity headphone types such as in-ear monitors, leave PowerMatch at its lower setting for ultra-low-noise performance. But if your headphones require more drive – most on/over-ear types, for example – press the PowerMatch button on the front panel to increase gain. XBass is a form of ‘bass boost’ that enhances low frequencies without muddying the midrange. It operates entirely in the analogue domain rather than messing with the digital signal via DSP and may be switched in or out of the signal path.
The hip-dac’s USB input handles audio data up to 32-bit/384kHz and supports the ‘SuperSpeed’ USB 3.0 standard, as well as USB 2.0 for backwards compatibility. It is asynchronous, meaning that the data rate is regulated solely by the hip-dac’s audio clock circuitry for accurate, data transfer from the source device. There are two USB ports – type A for audio data and USB-C for charging. The type A input features a ‘male’ connector, rather than a typical ‘female’ port. This arrangement provides greater mechanical integrity than the USB/Micro USB ports commonly found on DAC/headphone amps. It also offers an advantage to iPhone and iPad users, because “it accepts Apple’s Lightning to USB Camera Adaptor directly without requiring an additional USB adaptor”.
Two outputs are provided, a 3.5mm socket for normal headphones and a Pentaconn 4.4mm output for balanced connections. The 3.5mm output benefits from iFi’s proprietary S-Balanced circuitry, cutting crosstalk and related distortion in half when used with regular, single-ended headphone connections.
The hip-dac’s 2200mAh battery lasts for “around eight to 12 hours of playing time”, depending on volume level and how power-hungry the connected headphones are. It comes bundled with three USB cables: a USB-C OTG (On-The-Go) cable, for connecting Android devices and PCs/Macs with USB-C ports; a USB Type A cable; and a Type A to USB-C charging cable. (The Camera Adapter required to connect Apple iOS devices is not provided.) The hip-dac is a compact 102x70x14mm in its extruded aluminium enclosure and is available from February, it will be showcased at CanJam NYC 2020.