iFi Audio GO bar - Portable USB DAC / Headphone Amp

Small. But mighty.

The DAC section of the GO bar uses a powerful 16-core XMOS micro controller to process the audio data received at the USB input. The in-house team has programmed the XMOS firmware to optimise sound quality and ensure a perfect partnership with the GO bar‘s 32-bit Cirrus Logic DAC chipset.

A customised digital filter minimises pre-echoes and ringing artefacts. The GMT (Global Master Timing) precision clock system ensures ultra-low jitter.

• Ultra-res PCM up to 32-bit/384kHz via USB
• Native playback up to DSD256
• 2x DXD
• Full MQA decoding

External affairs

The GO bar’s smart alloy case sports physical buttons for precise volume adjustment plus controls to select between 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 is an asynchronous USB-C input and at the other a pair of headphone outputs.

• 4.4mm fully balanced output – headphones with a balanced cable/connector can benefit from the fully balanced circuitry of the GO bar
• 3.5mm S-Balanced output – The S-Balanced tech cuts crosstalk and noise by 50% with regular single-ended headphones.

Purity and power

The amp’s design combines sonic purity with power.

• 475mW into 32 ohms
• 7.5V into 600 ohms

?No headphone amp of such a diminutive size can match the GO bar’s ability to drive tricky headphone loads or work with a wider variety of headphones.

The GO bar also incorporates two power tuning technologies:

• iEMatch – attenuates power to suit high-sensitivity headphones and IEMs, it removes background noise and increases usable volume range
• Turbo – ramps up the gain by 6dB to satisfy more power-hungry headphones

The XMOS 16-Core chip processes the audio data received via the USB digital input.

This new low-latency XMOS microcontroller has greatly enhanced processing power. Compared to the current generation of eight-core chips, this new 16-core IC delivers double the clock speed (2000MIPS) and four times the memory (512KB), as well as the latest SuperSpeed USB standard.

iFi’s in-house digital development team has programmed the XMOS firmware to optimise sound quality and ensure a perfect partnership with the 32-bit Cirrus Logic DAC chipset used in the GO bar.

MQA (Master Quality Authenticated)

MQA is an award-winning British technology that delivers the sound of the original master recording. The master MQA file is fully authenticated and is small enough to stream or download. The GO bar adopts MQA technology to receive and decode MQA audio and provide master-level sound.

Visit mqa.co.uk for more information.

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.

TDK C0G (Class 1 ceramic) capacitors offer high stability and low losses for resonant circuit applications.

Getting ever closer to the theoretical ideal of pure, frequency-constant capacitance, these capacitors reduce capacitor-induced distortion to vanishingly low levels.

They are pricey but are a perfect addition to iFis products.

muRata control-type, low-ESR high-Q multi-layer capacitors. The ‘ESR control’ aspect of the Murata is something special. Their noise suppression abilities are impressive.

Panasonic OS-CON caps totaling 5,410uF give very-low Equivalent Series Resistance (ESR), excellent noise reduction capability and frequency response characteristics. In addition, OS-CONs have a long-life span and its ESR changes little even at low temperatures since the electrolyte is solid.

They are not often found in products costing

Tantalum capacitors are another example of the top-notch components iFi prefer. These polarised electrolytic capacitors have superior frequency and stability characteristics, giving them a super high volumetric efficiency.