Lexicon I-ONIX U42S Desktop Recording Interface Quick Pick Review

Lexicon I-ONIX U42S Desktop Recording Interface reviewed by EM author Babz in EM July 2009 issue
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The Lexicon I-ONIX U42S is an audio and MIDI interface supporting 24-bit/96kHz digital audio.

With today's trend toward mixerless recording, many functions such as patching, and setting input, monitor and master out levels are now shifted to the audio interface. Thus, it's increasingly more sensible to move the interface out of the rack and onto the desktop for easy access. Lexicon — famous for high-end reverbs and rack gear, but not necessarily the most friendly user interfaces — has experimented with various tabletop audio interface designs over the years with mixed results. Now, with the new I-ONIX Series USB interfaces, Lexicon debuts a bold new design based on in-depth research into home and project studio ergonomics. The line includes the 2-channel U22, 8-channel U82S and the midrange 4-channel U42S model, which has a street price of around $399.


The U42S is an audio and MIDI interface supporting up to 24-bit/96kHz digital audio via USB 2 with a unique ergonomic form factor designed to fit on your desktop between your keyboard and monitor. Its sturdy — yet lightweight — case sports a striking trapezoidal shape that will give your desktop a high-tech boutique look. An inviting silver and black front panel is angled upward for optimal accessibility, and features four input knobs each with 8-stage LED meters, two (yes, two!) headphone level controls and an extra large main output knob. To the right of the big knob is a Monitor Mix control that lets you balance between direct and playback signals for zero-latency monitoring. This approach is effective, but at this price point you don't get fancy features like individualized headphone mixes or onboard monitor effects. For that, you may want to consider stepping up to Lexicon's FW810S FireWire interface.

I was impressed with the overall elegance and simplicity of the U42S' user interface. Virtually every aspect of the design shows careful attention to workflow needs, such as back panel port labels printed across the top and designed to be read from the front of the unit, and well-placed headphone and instrument jacks flanking its two side panels. One thing missing, however, is an on/off switch, so plugging/unplugging is the only way to power up and down.

The U42S works with both Windows (XP and Vista) and Mac;however, for Mac users it requires an Intel chip. This is the first product I've seen that supports Mac but doesn't offer universal binary drivers, and thus I was unable to test it with my aging PowerMac G5. (Note: At press time, Lexicon added universal binary drivers and support for both Intel and PowerPC Macs — all downloadable atlexiconpro.com. — Eds.) Minimum system requirements are modest by today's standards, and my test computer, a 3GHz Pentium 4 PC with Windows XP SP2, performed ably.


The back panel has four mic/line inputs with locking XLR/TRS combi-jacks and two TRS balanced line outputs. Between each pair of inputs is a switch to engage 48V phantom power for that pair. It also provides MIDI and S/PDIF I/O. You can record up to four analog channels and two S/PDIF channels simultaneously.

The analog inputs leverage newly designed dbx mic preamps, which are described as “high voltage” and “ultra-low noise,” a claim that indeed proved true throughout my tests with a variety of mics and instrument sources. On vocals, guitars and amp cabinets, with both condenser and dynamic mics, the results were quiet, clean and transparent.

The unit is bundled with Steinberg Cubase 4 LE cross-platform DAW software, Lexicon's new Pantheon II VST/Audio Units reverb plug-in and Toontrack EZ Drummer Lite. Cubase LE 4 lets users record up to 48 audio tracks and comes with a suite of 25 VST effects plug-ins. The Pantheon II plug is a quality digital reverb that's processor-efficient, but to my ear isn't in the same league as Lexicon's hardware reverbs.


The Lexicon U42S offers a winning combination of user-friendly features, first-rate sound quality and a stylish look at an affordable price. Other than the missing on/off switch, the only thing I found lacking was any sort of printed manual. A PDF manual is on the installer disk, but I at least expected a small hard-copy Getting Started guide. With the USB audio interface market more crowded than ever nowadays, Lexicon has come up with a brilliantly conceived product that should make it a stand-out choice for home, mid-sized and project studios.

Value (1 through 5): 4