RME Fireface UCX II review: A compact, high quality and feature-rich audio interface with a price tag to match

RME has gained a loyal following for almost unmatched support of its hardware, years and years after release. Clean onboard preamps, low latency over USB and quality converters also make RME a popular brand in location recording circles. Buying RME products, then, is a long term investment – but built-to-last quality comes at a price.

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The new Fireface UCX II sits neatly in the product line-up between the dinky Babyface Pro and the larger UFX models. Despite Fireface in the name, legacy Firewire ports have been ditched and, for maximum compatibility, RME has stuck with good ol’ USB-2. There’s no MADI available – and fewer ins/outs than on a UFX – but a stunning new colour display and clear metering push the outgoing UCX model firmly into the shade.

UCX II has a definitive edge over the earlier design (and competing products such as the MOTU UltraLite mk5) with built-in USB recording and playback, allowing users to track sessions in standalone mode, well away from the distractions of computer screens or pesky fan noise. Nice move, RME.

Taking style tips from the company’s most recent series of audiophile converters, the UCX II is housed in a half-rack case. On the front panel, two digitally controlled mic inputs each offer a healthy 75dB of available gain. Alongside these are two further instrument/line inputs, a single headphone socket, the display, plus buttons and a rotary encoder to control everything. On the back, there are four further line ins, six line outs, MIDI, and a range of digital in/outs including ADAT. Further still, a break-out cable gives access to both AES and SPDIF i/o.

This feature set is most suited for home and project studios, where the use of 1-4 simultaneous inputs is the norm but gives ample scope for adding parts later on. This may include connecting boutique external preamps via the dedicated line inputs or adding further ins/outs using the ADAT ports (an optical cable is included in the box to get you started along this path).

The six line outs allow for multiple sets of studio monitors, a headphone amp feed, and even a surround monitoring set-up. For larger-scale operations, the lack of a second ADAT bank might hamper progress beyond this point – such users would be better off with a larger interface – but RME has crammed maximum features into a compact format.

RME’s TotalMix software provides more precise control of the UCX II, which runs on the host computer or iPad, acting as a remote control. There’s also an app to use the interface with an iPad alone but this is a chargeable extra. Despite a slight learning curve, it’s fairly easy to get going with producing headphone mixes, routing and exploring settings. A range of DSP can be added to any live input, including EQ, compression/gating, reverb and delay. While the processing isn’t typically printed to the recorded track, there’s an option in the settings menu to include EQ and dynamics when recording. Loop-back routing is also an option – handy for the podcasting and live-streaming revolution.

We’re impressed by the attention to detail in TotalMix and the associated hardware capability that sets RME apart. For example, the ability to properly live-monitor a mid/side pair of inputs, and individual reference level setting for each line in/out, making it more straightforward to connect up a wide range of external gear.

However, there is an elephant in the room; the lack of proper interface scaling in the TotalMix desktop app. Set at 100 per cent, it’s a little too small on a laptop screen; at the next zoom level up it spills off the screen and scrolling is required. This is frustrating and an update seems long overdue. On the iPad, the user interface works a little better since you can quickly toggle between zoom/view modes.

As expected, UCX II’s preamps deliver plenty of clean gain to even the most gain-hungry microphones, such as our trusty Shure SM7B. There’s plenty of output from the headphone amp too – it can get seriously loud and often we found ourselves turning the DAW playback feeds way down to balance these with live inputs. We just wish RME made room for a second headphone socket, even if it carried the same mix as the first.

Setting up a headphone mix with a subtle high shelving boost, gentle compression and some reverb is plain sailing with TotalMix. Despite display resolution frustration, everything works instantly while snapshot support makes recall a breeze for subsequent tracking sessions. On most interfaces of this type, on-board reverb algorithms are grainy and unpleasant, but that’s not the case with the RME. Instead, serviceable reverbs – combined with subtle EQ/compression – put the performer at ease rather than detracting from the job at hand.

UCX II’s D/A converters aren’t class-leading like those of the company’s ADI range but are perfectly capable when tracking and mixing. Playback reveals plentiful articulation and there’s slightly increased high-frequency content in cymbals and snare transients when compared to the onboard sound of our M1 MacBook. The UCX II is geared towards achieving high-quality results in both recording and playback.

Tracking a software instrument whilst also playing back 16 other audio/software instrument tracks, we experienced uninterrupted playback even when running at the lowest buffer size of 32 samples. At the 48kHz project setting, this equated to an agile round-trip latency of just 3ms. For larger projects and buffer sizes increased two steps to the 128-sample mark, the interface still operated a fair margin below the 10ms gatepost. This performance won’t rival that of Thunderbolt, but it’s impressive for USB.

RME’s UCX II is almost unrivalled in its combination of features-for-size and real-world availability. You pay more for RME quality, but the new UCX fits perfectly into the existing range, offering a whole lot more than the Babyface and its previous incarnation. In the context of the RME product line-up, this interface offers superb value for money. For those who dabble with standalone use of their audio interfaces, on-board recording will prove to be a feature that helps sweeten the deal.

Key Features

• USB-2
• Digital qualities of up to 24-bit/200 kHz
• 2 digitally controlled mic preamps (up to +75dB of gain)
• 115 dBA AD/DA dynamic range
• 2 instrument level inputs
• 8 simultaneous TRS line ins and 6 line outs (line outs have switchable level and are DC-coupled)
• 1 headphone socket
• ADAT in/out
• AES/EBU and SPDIF digital in/out via supplied break-out cable
• MIDI in/out sockets
• USB drive recording/playback
• Supplied with USB A-to-B cable, TOSLINK optical cable, digital break-out cable and PSU
• Weight: 910g
• £1239
• Contact RME | Synthax
• Buy: Sweetwater, Thomann