iFi GO Bar pocket rocket is best bar none
Top-of-the-line USB model in iFi GO Series of ultraportable DAC/headphone amps, the small yet mighty ‘GO bar’ is the world’s most powerful headphone amp of its size Southport, England – iFi’s acclaimed DAC/headphone amps have formed a cornerstone of the company’s product range since its formation in 2012, delivering brilliant sound from smartphones, tablets, PCs, Macs and more. Last year, iFi introduced the GO blu, first in a new line of ultraportable, pocketsize DAC/amps called the GO Series; now it’s joined by the GO bar, taking the ‘big sound in a small package’ concept to a whole new level. Like to GO blu, the GO bar is eminently pocketable, with a robust yet lightweight alloy enclosure that measures 65x22x13mm and weighs 28.5g. But, while the GO blu majors on the convenience of Bluetooth connectivity to devices like smartphones when you’re on the go, the GO bar connects to source devices via USB and focuses on pure performance. Whether you’re commuting, working remotely or at your desk, or simply travelling for pleasure, the GO bar is the perfectly portable way to make headphones sound heavenly when connected to desktop PCs, laptops, phones, tablets or any other digital source device with a USB port.
The GO bar is not the first USB DAC/headphone amp of such diminutive size, but its specification is unrivalled. Its hi-res format compatibility and sonic tuning facilities are second to none, and its amp stage is the most powerful in the world for a headphone amp of this size. Small yet mighty, indeed.
What’s up DAC?
The GO bar’s digital audio circuitry is based around a 32-bit Cirrus Logic DAC chipset with advanced multi-bit modulation. This is coupled with a customised digital filter to minimise pre-echoes and ringing artefacts, and iFi’s GMT (Global Master Timing) precision clock system to ensure ultra-low jitter, thus reducing errors and distortion in the digital audio signal. The DAC is fed by a powerful 16-core XMOS microcontroller, which processes the audio data received at the USB input. iFi’s in-house digital development team has programmed the XMOS firmware to optimise sound quality and ensure a perfect partnership with the Cirrus Logic DAC. Hi-res PCM is supported to 32-bit/384kHz, alongside DSD64, 128 and 256, and single- and double-speed DXD. The DAC’s architecture maintains DSD data in true native form, unlike other DACs that convert DSD to PCM.
The GO bar also delivers full decoding of MQA, the hi-res streaming technology. This means that the complete ‘three unfold’ decoding process is performed internally, as opposed to just the final unfold in the manner of an MQA ‘renderer’, which makes the GO bar an excellent choice for subscribers to Tidal’s ‘HiFi Plus’ tier where Tidal Masters (MQA) content can be found.
Balance of power
Remarkably given its diminutive size, the GO bar’s analogue circuitry features balanced design with a symmetrical twin-channel output stage. This topology, usually reserved for larger and more expensive amplifiers owing to its cost and complexity, reduces noise and crosstalk in the signal path by fully separating the left and right channels. Rather than resort to space- and cost-saving integrated circuit solutions which compromise sonic quality, the GO bar’s circuitry packs in high-quality discrete components such as TDK C0G ceramic.
The GO bar’s robust yet lightweight alloy enclosure sports a range of useful LED indicators, controls and even a balanced output capacitors, Panasonic OS-CON aluminium polymer capacitors, and high-density tantalum capacitors, plus Taiyo Yuden and Murata inductors, all with excellent characteristics for high-quality audio applications. Special attention has also been paid to power supply filtering, dramatically reducing signal noise introduced though the USB input.
The amp’s design combines sonic purity with exceptional power. In fact, with an output of 550mW (into 64 ohms) and 7.5V (into 600 ohms), no headphone amp of such diminutive size can match its impressive ability to drive even tricky headphone loads – that’s enough current drive for 16-ohm headphones and sufficient voltage drive for 600-ohm headphones. Combining serious muscle with beguiling finesse, the GO bar sounds wonderful with a wider range of headphone and earphone types than any other ultraportable USB DAC/amplifier. Adding to this versatility, the GO bar incorporates two power-tuning technologies, enabling adjustment of its output to suit specific requirements. IEMatch attenuates power to suit high-sensitivity headphones and in-ear monitors, removing potential background noise and increasing the usable volume range. Conversely, Turbo mode ramps up the gain by 6dB to satisfy more power-hungry headphone types.
Suits you, sir
Further user-adjustable sonic tuning is provided in both digital and analogue domains. Four bespoke digital filter options – Standard, Bit-Perfect (non-oversampling), Minimum Phase, and GTO (Gibbs Transient Optimised) – can be selected according to preference, while iFi’s familiar analogue processing modes, XBass+ and XSpace, can also be switched in or out of the signal path according to taste. X Bass+ is a sophisticated form of ‘bass boost’ that enhances low frequencies without muddying the midrange, useful with earphones and open-back headphones that may lack deep bass. XSpace is designed to compensate for the ‘in-head localisation’ effect that can occur when using headphones to listen to music that was mixed using a pair of speakers, effectively widening the headphone soundstage to deliver a more spacious and speaker-like experience. With such a variety of digital streaming platforms, file types, headphones and earphones to choose from, not to mention music styles and recording qualities, this suite of sonic tuning options is valuable to ensure optimal sound – and unique in a DAC/headphone amp of this type and size.
Both sides of the GO bar’s diminutive circuit board are packed with high-quality components to deliver a remarkable sonic performance for such a small device.
Most ultraportable USB DAC/headphone amps offer little or no control via the device itself, with volume adjustable only via software running on the connected source device. The GO bar is different, its smart alloy case sporting physical buttons for precise volume adjustment – which can be synchronised with the volume controls on the source device – together with controls to select between the various sonic tuning options. A column of coloured LEDs provides a handy guide to the format and sample rate of the digital audio currently playing, and whether XBass+ and/or XSpace are engaged. At one end of the GO bar is an asynchronous USB-C input, at the other resides a pair of headphone outputs. One of these is a fully balanced 4.4mm output, enabling headphones equipped with a balanced cable/connector to make the most of the GO bar’s balanced audio circuitry. The other is a 3.5mm output utilising iFi’s ‘S-Balanced’ technology – this cuts noise and crosstalk by 50 per cent with regular single-ended headphone connectors. Both outputs are gold plated to maintain contact quality over time.
To celebrate its 10th anniversary, iFi has also created an eye-catching special edition of the GO bar. Limited to 1000 pieces, the GO bar Anniversary Edition – or ‘GOld bar’, if you will – replaces the standard version’s alloy enclosure with a copper chassis, further enhancing build quality and electrical shielding, and smothers it in 18ct gold plate. Power supply filtering is also further enhanced, ensuring the Anniversary Edition – which, at 64g, is more than twice the weight of the standard GO bar – is truly the ‘gold standard’ among ultraportable USB DAC/headphone amps.
Ready for anything
Both the standard GO bar and the Anniversary Edition come with a generous accessories pack to get the tunes flowing right off the bat. Apple users will love the bespoke Lightning to USB-C cable, engineered by iFi so you don’t need to add Apple’s Camera Adapter dongle to use the GO bar with iOS devices, as you do with other USB DACs – thus reducing bulk and cost. Android users, meanwhile, will appreciate the USB-C OTG cable, which can also be used with USB-C-equipped PCs and Macs; a USB-C to USB-A adapter is also included, thus covering most bases straight out of the box. And there’s a leather travel case too, ensuring your GO bar is well protected wherever you choose to take it.
Specifications ifi Audio GO Bar
|DAC||Bit-Perfect DSD & DXD DAC by Cirrus Logic|
|Headphone Output||BAL 4.4mm/UnBAL 3.5mm|
|[email protected]Ω; [email protected]Ω
[email protected]Ω; [email protected]Ω
|Output Impedance||<1Ω (BAL/UnBAL)*|
|SNR||132dBA / 108dBA (BAL/UnBAL)|
|DNR||109dB(A) / 108dB(A) (BAL/UnBAL|
|THD + N||Balanced
|<0.002% (6.5mW/2.0V @ 600Ω)
<0.09% (100mW/1.27V @ 16Ω)
|Frequency Response||20Hz – 45kHz (-3dB)|
|Power Consumption||<4W max.|
|Dimensions||65 x 22 x 13.2 mm (2.6″ x 0.9″ x 0.5”)|
|Weight||28.5g (1.0 oz)|
|Warranty period||12 months|