Universal Audio Volt 2 USB-C audio interface review: Portable potential

Founded in 1958 by audio engineer Bill Putnam, Sr., Universal Audio is well-known in the pro audio world for manufacturing top-shelf outboard gear (preamps, compressors, and the like) and for the best-in-class audio converters found in its Apollo line of interfaces. In late 2021, the company announced its new Volt series, which aims to deliver UA’s sought-after analog sound and high-quality conversion in its most affordable and travel-friendly audio interfaces. I recently spent some time on the road recording and traveling with the Universal Audio Volt 2, a 2-input/2-output model that concentrates on providing the cleanest signal in a compact form factor. Here are my thoughts on the interface’s sound, design, and workflow to assess how it stacks up against similar USB interfaces in its price range.

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The Universal Audio Volt 2’s design

The Volt series runs the gamut in size and price, from the 1-input/2-output Volt 1 at $139 to the 4-input/4-output Volt 476P at $469. While each of the Volt interfaces is bus-powered via USB-C and includes a unique “vintage” tonal option—more on that later—a few of the models also include a built-in FET compressor styled after the company’s 1176LN Compressor, a relatively loud and bright-sounding compressor capable of producing responsive, transparent signal leveling but costing several thousand dollars. The Universal Audio Volt 2‘s distinguishing feature, however, is its panache and portability: its clean rectangular chassis measures roughly 7 x 5 x 2 inches, it weighs just 1.4 pounds, and it requires no wall wart thanks to its USB-C bus-powered design.

From a design standpoint, the Volt 2 significantly improves on Universal Audio’s last portable offering, the 6 x 6 x 3-inch, 2.4-pound Apollo Twin X, which requires wall power. The Volt 2’s control panel is also organized in a straightforward and easy-to-use manner, with most of the gain controls and monitoring options clearly labeled and placed alongside the interface’s two combo XLR/¼-inch inputs, which accept mic, instrument, and line level signals. A few backlit buttons offer access to 48-volt phantom power, instrument signal selection, and the Volt’s distinctive “vintage” mode, which engages solid-state electronics to add soft clipping and warm saturation to the input signals in the style of the Universal Audio Solo 610 Tube Preamp.

Like the Focusrite Scarlett 2i2, PreSonus AudioBox GO (which I reviewed in 2022), and other similarly-sized 2-in/2-out USB interfaces, the Volt 2 features a single 48-volt phantom power toggle that sends voltage to both inputs simultaneously. This won’t pose a problem for most users, but this limitation is something to keep in mind if you’re using vintage ribbon mics or other equipment that may be damaged by phantom power. On the conversion side, the Volt 2 features an impressive max audio conversion rate of 24-bit/192kHz, matching that of Universal Audio’s flagship Apollo line of interfaces and allowing users to record extremely high-fidelity audio with a very small footprint.

One significant design limitation of the Volt 2 is its lack of onboard DSP processing, which is required to run Universal Audio’s vast library of over 200 plugins. While none of the interfaces in the Volt series can run Universal Audio’s plugins, this speaks to a larger caveat in the company’s ecosystem; to run most UAD plugins, you need an Apollo-series interface or an external UAD accelerator. This is somewhat remedied yet further convoluted by the recent introduction of UAD Spark. This new subscription service offers access to around 20 of the company’s plugins without an Apollo interface or other external processors. Long story short: you’ll save a lot of money opting for a Volt-series interface over an Apollo, but you won’t be able to use it to run most of Universal Audio’s plugins.

Getting started with the Universal Audio Volt 2

Setting up the UA Volt 2 for recording is a breeze thanks to its bus-powered design. To get started, I removed the interface from its packaging, unpacked the included USB-C cable, and connected the Volt 2 to a USB port on my MacBook Pro. The Volt 2 immediately powered on and appeared as an available device for audio input and output in Logic Pro, my preferred digital audio workstation. If you’re running the Volt 2 into an older USB hub or want to conserve battery on your device, an included 5VDC-to-USB connector allows you to power the interface with your own USB-to-wall power adapter.

I primarily tested the Volt 2 while traveling, which required that I set it up and pack it away in several different hotel rooms with workspaces of varying sizes. Next to a 13-inch laptop, the Volt 2 is a perfectly-sized interface for assembling a lean and mean mobile recording rig, and because it doesn’t require wall power, it’s easy to set up pretty much anywhere. While on the road, I only had an electric guitar and bass at my disposal for recording, both of which I connected directly to one of the Volt 2’s 1/4-inch instrument inputs while monitoring through the interface’s headphone output using a pair of KRK KNS 8400 over-ear headphones. I also used the Volt 2’s direct monitoring feature, which offers latency-free monitoring of the input signals via a front panel switch to ensure a natural and comfortable performance experience.

Suppose you’re setting up the Volt 2 as part of a larger studio setup. In that case, the interface features left and right TRS outputs on its rear panel for connecting to studio monitors and two MIDI ports for connecting older synths and other MIDI-compatible devices. Some smaller two-preamp interfaces like the Apollo Twin include ADAT to allow users to expand their rigs with additional inputs and outputs. While I would have liked to see this feature included in the Volt instead of the older and less commonly used MIDI connectors, it would likely mean a significant increase in cost.

The Universal Audio Volt 2’s sound

The UA Volt line promises clear high-resolution audio conversion that follows in the footsteps of the company’s industry-standard Apollo line, and the Volt 2 stacks up very well upon comparison. Compared to audio recorded with similar two-input interfaces, the Volt 2 sounds distinctly “open” in its high-frequency range with a relatively detailed midrange that doesn’t suffer from much of the obscure and “muddy” character that is often a hallmark of its price range. In these respects, the converters in the Volt 2 sound remarkably close to those in the Apollo, though I found the low mids in the Apollo converters to be slightly more nuanced and focused. While these differences are relatively minor, this effect can sometimes compound when multitracking and may create extra mixing work on the back end.

The Volt 2’s unique “vintage” feature also adds another level of creative flexibility to the equation, and it was great to have this option while traveling with limited gear. With the mode engaged, the Volt’s inputs sound distinctly analog and old-school, replacing its clean and pristine default sound with warm, round, saturated tone. The vintage mode also engages a soft clipper to flatten peaks in the input signal in a behavior similar to analog tubes, lending a character that’s particularly great for early rock and Motown-esque bass and guitar tones. While it’s probably not a one-size-fits-all sound, the vintage mode is killer for adding an extra level of character and “glue” to minimalist demo recordings and overdubs.

So, who should buy the Universal Audio Volt 2?

The Volt 2 features some of the clearest and most musical-sounding converters I’ve tested in its price range. If you’re in the market for a simple two-input travel interface, you’d be hard-pressed to do better. Its vintage preamp option is also incredibly versatile. It adds a distinctly pleasing “pre-mixed” analog quality to input sources, saving time on mixing and bouncing, particularly when recording demos or overdubs. I wish that the Volt 2 included ADAT or S/PDIF for adding additional inputs instead of MIDI—the tiny, forward-facing design of the Volt 2 seems at odds with everything that old and bulky MIDI gear stands for—and, unfortunately, the interface can’t run UAD plugins. Still, if you can look past these design limitations, the Universal Audio Volt 2 is an incredibly flexible and relatively affordable travel interface with the potential to deliver studio-quality recordings on the go.

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