Acoustic Research UA1 Review

As high resolution music becomes even more prevalent, music fans are seeking solutions to play back their high-res albums not just on their hi-fi systems, but on their computers too. And it’s not just high resolution music – with the advent of higher quality music streaming services, and the acceptance of the computer as a genuine hi-fi playback medium, there has never been more demand for a high quality playback solution both for at home and on the go.

Enter the Acoustic Research UA1 – a tiny, bus-powered, high resolution DAC with integrated headphone amp, featuring an asynchronous USB interface and the same M-Class audio engine as found in Acoustic Research’s M1 high res music player.


The UA1 uses the Burr-Brown PCM1794a DAC, and can support sampling rates of up to 24-bit, 192KHZ, with higher sampling rates supported via high precision conversion using the included JRiver Media Centre software. A colour LED status display shows the bit-depth and sampling rate of the current source.

The headphone amp is a class AB design, employing the Texas Instruments TPA6120A2 current-feedback amplifier chip. The TPA6120A2 is an ultra-low distortion (0.000635% THD, 1KHZ, half rated power), 1.5W per channel headphone amplifier offering up to 128DB of high dynamic range, as well as an extremely low noise floor. It also features gain independent frequency response, enabling the entire bandwidth of the amplifier to be used regardless of the volume level.

First Impressions

In the box, you’ll find the amplifier itself, nestled in foam. You’ll also find the USB A-B cable, along with some documentation and a software CD. The CD contains windows drivers to enable the device to play back high-resolution content (OS X and Linux support USB Audio Class 2 natively), as well as JRiver’s media centre software for both Mac OS X and windows. A linux version is also available from JRiver’s website, which i would recommend visiting to download the latest version regardless of platform.

On the front of the device, you’ll find the 6.3MM headphone output, along with a hardware volume control. The control is detented, offering a tactile click as you turn it.

Around back, you’ll find the USB connection, as well as an optical output and 2 very substantial brass RCA connectors.

Build quality is exceptional. The device is finished in stylish angular aluminium casing, with an AR logo adorning the top and slits for cooling on either side. The front and rear panels of the device are plastic, though the volume dial is metal and feels extremely solid with no play or flexing during use. 2 Rubber strips beneath the device serve as feet keeping it in place on most surfaces.


The device is simple in usage. For the record, I didn’t use the included JRiver media centre software, as i already have appropriate playback software. Connection to my MacBook pro took seconds, at which point the device was instantly detected as an output device. The bit-depth and sampling rate settings were also instantly detected and correctly configured.

In use, I noticed that despite the UA1 having a hardware volume control, the software volume control of my Mac was not bypassed. This resulted in some experimentation to achieve the correct balance between the hardware control of the amp and the software control of the Mac and the playback software. Eventually, I left the Mac set to around 80%, with the playback software at 100%. I then adjusted the listening level using only the hardware volume control..


To assess the units sound, I used a range of source material, including 24-bit, 192KHZ and 96KHZ high-res FLAC files, lossless CD-quality (16-bit, 44.1KHZ) WAV rips, and my iTunes library, consisting of mostly 192 and 320KBPS MP3s.

Being a sucker for convenience, I often spend my downtime relaxing in front of my mac, iTunes library loaded, headphones connected to the Mac’s built-in headphone output. I know, it’s the ultimate audiophile sin. But it really doesn’t sound too bad.

Until, that is, you switch to a device such as the UA1. Even straight out of the box, the difference is immediately obvious. The sound is sharper, more powerful, more focused and a whole lot more listenable. It’s as if a veil has been removed, the UA1 effectively disappearing leaving nothing between you and the music.

I began my testing with the track ’39’ from ‘Return of The Champions’, a live album recorded in 2005 by the remaining members of Queen and Paul Rodgers. This is an excellent recording, with stunning room ambiance which the UA1 delivered with aplomb. Vocal nuances are also far more prevalent, resulting in a performance that is enthralling and emotional.

The UA1 also excels in subtle detail delivery, though perhaps due to the full nature of its sound I did at times struggle to pick out some finer details, such as the acoustic guitar in Guns n’ Roses ‘Since I Don’t Have You’.

Though with a product this musical, a little bit of detail going astray is far less of a concern. In fact, it’s negate-able, because what the UA1 ultimately offers is a sound that is so easy to listen too for hour after hour. It doesn’t matter what you feed it, because the result will be glorious, sublime musical pleasure.


It’s hard – no – impossible not to love the UA1. This tiny little device makes it so easy to enjoy your computer-based music collection in the best way possible. It’s built to last, ready to take on the new wave of high-resolution music flooding the market, and it sounds stunning. Have you ordered yours yet? Highly recommended.

By Ashley

I founded Audio Appraisal a few years ago and continue to regularly update it with fresh content. An avid vinyl collector and coffee addict, I can often be found at a workbench tinkering with a faulty electronic device, tweaking a turntable to extract the last bit of detail from those tiny grooves in the plastic stuff, or relaxing in front of the hi-fi with a good album. A musician, occasional producer and sound engineer, other hobbies include software programming, web development, long walks and occasional DIY. Follow @ashleycox2

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