MOTU UltraLite Mk5

MOTU’s newest UltraLite interface is a Jack of all trades... and master of most of them!

Since the Mk1’s release in 2006, the UltraLite has always been something of a misnomer. While they’ve always ‘only’ been half‑rack interfaces, UltraLites have also been pretty rugged affairs, and so not at all light in terms of weight. They’ve also managed to cram a remarkable amount of I/O into their compact chassis, so they’re not light on channels either. In fact, they’ve arguably encroached on the ‘full‑fat’ interface territory occupied by MOTU’s own 828s, and the latest Mk5 is no exception.

The UltraLite Mk5 has been around for some time now, but while reviewing it last year, I contacted MOTU to mention a few limitations to the software control side of things, and they replied to tell me that they had a major update planned that would address my wish‑list and add more features besides — some of which come directly from the recently launched next‑gen 828. I’ll cover those features later on, but first, the basics.

Let There Be Lite

The UltraLite Mk5 is a USB 2.0 interface. The USB 2 standard has more than enough bandwidth for the Mk5’s I/O count, and its use here has allowed MOTU to make the Mk5 class‑compliant — so you can connect it to a macOS, iOS, iPadOS or Android device without needing any drivers. (On Windows, as ever, you need to install ASIO drivers to use it with most DAWs.)

The I/O on offer are many and varied. You get two mic/line/instrument inputs on combi sockets on the front, plus a stereo headphone socket. Round the back, you get six further analogue line‑level inputs, a whopping 10 line outs, a pair of optical I/O (for ADAT or S/PDIF), a pair of S/PDIF coaxial I/O, and full‑size MIDI I/O. Completing the socketry are the USB‑C port and a 15V DC power inlet. Speaking of power, unlike the first three generations of UltraLite, which had FireWire connectivity and could be bus‑powered, the USB Mk5 must be connected to a PSU. Not much of a problem if you’re using it with a computer or laptop, where you’ll probably be near a mains socket anyway, but it might be a frustration for people who use tablets and the like for mobile recording.

The rear panel hosts no fewer than six line inputs (in addition to the front‑panel combi sockets), and a whopping 10 line outs, plus digital I/O and full‑size MIDI ports.

Twist It, Push It

The front panel offers hands‑on control over the two combi inputs, the headphone output and the monitor level, as well as power on/off (via a long press of the main volume encoder). Phantom power and an input pad are engaged individually for each preamp using buttons along the bottom fo the front panel, which feature blue and red backlights for the pad and phantom power respectively. Encoders above those buttons adjust mic gain — up to a massive +74dB. The third encoder adjusts monitor level or, after a short click, the headphone output. The two gain knobs also provide access to a housekeeping menu: a click on the channel 2 encoder brings up options on the screen for changing the sample rate (all the usual rates are available, from 44.1 to 192 kHz), choosing a clock source (internal, optical or S/PDIF), the optical I/O format (ADAT or S/PDIF, independently for input and output), engaging ‘thru’ behaviour on the MIDI output port, setting the display time‑out time (30 seconds, half an hour or off), displaying the serial number and firmware version, and performing a factory reset. The channel 2 encoder scrolls through the options and selects/changes them with a click, while channel 1’s encoder lets you click to go up a level.

When the display is timed out, a solitary pixel slowly bounces around the screen in Pong fashion, to let you know the unit is still on. In its default state, though, the screen functions as a meter bridge, showing the levels going into and out of all the analogue I/O, alongside the current sample rate, clocking status, and digital I/O activity (including MIDI). It’s clear, bright and easy to read, and the menu is easily navigable.

The Device page in CueMix. The monitoring section at the top has been recently added, and lets you set up A/B monitor switching.

CueMix

Like other MOTU interfaces, the UltraLite Mk5 is graced with built‑in DSP mixing abilities, which are configured and controlled using the CueMix software. The Home tab duplicates the front‑panel functionality, with knobs for monitor/headphone output level and preamp gain, and buttons for pad and phantom power. There are also buttons here to enable direct monitoring, whereby each analogue input can be sent directly to either or both of the monitor and headphone outputs, avoiding the computer’s audio buffers and providing near‑zero‑latency monitoring.

The Device page provides all the same clocking, sample rate and digital I/O options as the front‑panel menu, as well as drop‑down menus for setting the input meters to pre/post fader, engaging a low‑latency mode (Windows machines only), making the stereo output mixes from the computer available to the input mixer (so any mix you set up for a pair of outputs on the UltraLite will get its own fader within each output mix tab), and for changing the buffer size. This can be set as low as 16 samples, which at 44.1kHz yielded a commendably low latency of 1.2 and 2.0 ms (input and output, respectively). At a less CPU‑taxing 64 samples, I/O latency was still a perfectly serviceable 2.2/3.7 ms.

The UltraLite Mk5 hosts a fully featured DSP mixer, with EQ and dynamics processing available to every analogue input.

There’s a software loopback input, for recording the stereo output from other software into your DAW, and you can choose whether this appears to your computer on channels 9+10 (the default) or 1+2. The latter option is intended for fussier bits of software that only ‘see’ the first stereo input on your machine.

You also get the option to make any of the analogue, digital or loopback I/O visible to Windows. For most, I imagine the default option of having only inputs and outputs 1+2 available will do fine, but if you want your Zoom calls coming out of ADAT channels 7+8 and Cortana to respond to the S/PDIF inputs, or whatever, you can make it so. Finally on the Device page, you can save and load presets (which store the entire state of the UltraLite), view the interface’s serial number and current firmware version, and update the firmware and CueMix app.

Next is the Input tab, which again offers control over phantom, gain and pad settings on inputs 1+2, and which also lets you choose whether the signal sent to your DAW comes pre or post any DSP processing (more on which below). You can also add up to 20dB of digital gain to any of the line inputs here too, as well as flip the polarity on any/all of the analogue inputs, and set the line‑in DAW feeds to pre/post DSP. At the bottom of this window you get level metering for the S/PDIF phono and optical (S/PDIF or ADAT) inputs.

Moving on, the Output tab provides output trim controls for all the analogue outputs (in pairs), plus control over the headphone and monitor level. The monitor section at the top additionally lets you create a Monitor Group. By default, outputs 1+2 are controlled by the monitor level knobs (both in the CueMix software and on the front panel), but you can select any other output to also be governed in the same way. So, you could connect a subwoofer to output 3 and have your monitors and sub all be controlled by the front panel, or even have level control over a surround setup or a 10‑speaker Atmos array. That’s pretty significant, and I think makes the UltraLite Mk5 the smallest and cheapest ‘Atmos‑ready’ interface you can buy. And, because the headphone output is independently addressable (via a menu just below the Monitor Group section), you could even route a binaural downmix to that while controlling all 10 of your Atmos speakers from the front panel. It’s not as ‘Atmos‑native’ as the Audient ORIA reviewed elsewhere in this issue, but if you needed to set up a portable (if such a thing exists) or temporary Atmos rig, the Mk5 would have you covered.

...offers level control over a surround setup or a 10‑speaker Atmos array. That’s pretty significant, and I think makes the UltraLite Mk5 the smallest and cheapest ‘Atmos‑ready’ interface you can buy.

At the bottom of the Output window, you can choose which of your CueMix mixes comes out of the phono and optical S/PDIF outputs, and also what comes out of the TOSlink port when you’re using it for ADAT. You can either present the eight outputs to your DAW for use with an external D‑A converter, or feed it from the first eight line inputs — a setting it remembers when you disconnect the Mk5 from the computer, meaning you can use it as a standalone ADAT converter. (As ever, the ADAT I/O can carry eight channels at base sample rates, or four at 88.2 or 96 kHz.) Finally for the Output options, you can select the loopback source in much the same way as you can the headphone out: it can mirror any of the hardware outputs, or be fed from any of the CueMix busses.

Making Mixes

The remaining tabs are essentially duplicates, and let you set up individual stereo mixes for each of the analogue outputs. All of the inputs (including digital) are fair game for mixing, and all of the analogue (but not the digital) inputs have access to a four‑band parametric EQ and a compressor, with the two front‑panel combi inputs also getting a gate. There’s a three‑band parametric EQ available to each line output pair. On both the input and output EQs, the uppermost and lowermost bands can be set to shelving or peaking types, with the lowest gaining an additional LPF mode. The slopes or Q of the shelving/high‑pass filters can’t be adjusted.

Additionally, there’s a built‑in reverb that can be accessed by all of the inputs, including the ADAT and S/PDIF ins. Rather than getting a dedicated aux on each channel strip, this has its own tab at the bottom, for adding reverb in the ‘sends on faders’ mode. There’s only one global reverb mix, but as on the other mix tabs, you can send varying amounts of that mix to other outputs. The reverb parameters themselves can be adjusted by clicking the little ‘decay time’ window on the right of the Reverb tab. This opens up a plug‑in‑like GUI, with all the usual parameters (pre‑delay, decay, damping, stereo width), plus a choice of small, medium and large spaces.

In short, then, you can do some pretty sophisticated mixing using only CueMix. Need to send different foldback mixes to different performers while recording? Easy. Want to send a click track from your DAW to a drummer’s in‑ears, while sending backing tracks and soft synths to front of house? No sweat. The CueMix interface is neat and uncluttered, and gives you the ability to rename channels, and to hop to the next/previous channel’s EQ and compression window using your keyboard’s arrow keys, which makes setting up a mix a quick affair.

Specifications

In terms of the Mk5’s technical performance, the specs are impressive. The mic inputs claim an EIN of ‑129dBu (A‑weighted), THD+N (unweighted) of ‑115dB, and a dynamic range of 115dB (A‑weighted). The instrument inputs are only 4dB noisier, and offer the same +74dB maximum gain as the mic preamps. The front‑panel jacks present a 1MΩ impedance to unbalanced sources.

The line inputs boast an even more impressive dynamic range of 120dBA, and a similar THD+N figure of ‑113dB, while the line outputs claim a quite remarkable dynamic range of 124dBA. That puts the UltraLite Mk5’s D‑A performance in the company of products like the Focusrite Clarett+, and even Prism’s flagship multi‑channel converter, the ADA‑128. In other words, it’s well into ‘mastering quality’ territory.

Like those of other MOTU interfaces, the line‑level inputs and outputs are DC‑coupled, meaning they’re capable of sending and receiving 0Hz signals (ie. direct current). This means you can use them to send and receive control voltages to and from modular synthesizers, using any software that allows it. Some DAWs can do this using their own bundled plug‑ins (namely Bitwig and Ableton Live), and there’s a host of third‑party options too, from Expert Sleepers and NI among others.

What’s New?

Earlier this year, MOTU released a major firmware update for the Mk5, along with a new version of CueMix. Updating both was simple; the firmware update took seconds and could be performed from within CueMix, while the CueMix update necessitated a reinstall and a reboot. So what do you get for your trouble?

If you’re anything like me, you’ll have noticed an omission among the monitor control facilities in CueMix. Being able to create a Monitor Group is all well and good for subwoofers and surround systems, but what if you’ve got more than one stereo pair of monitors? The answer, thanks to the new update, is AB mode. Click the new AB ON button in CueMix (it’s visible in both the Home and Output pages), and it designates outputs 1+2 and 3+4 as monitor output pairs, which you can switch between using the A and B buttons. You can also engage them both by hitting the Both button.

Also new is a talkback feature, whereby you can select any of the analogue inputs as the talkback source, and route it to any/all of the analogue outputs. You can also set the talkback level, a dim amount, and choose whether the Talk switch is momentary or latching. And, of course, whichever input you choose as the talkback source still gets to use its EQ and dynamics processing.

Finally, and perhaps most significantly, the new update allows the UltraLite Mk5 to be controlled remotely, from any computer or mobile device that’s connected to the same network as the UltraLite host. In my case, that meant I could control the UltraLite that was plugged into my Windows machine using the CueMix app on my iPhone (the same app I’d also use if I wanted to connect the Mk5 to my iPhone directly). All you need to do is enable Network Control in the Device tab in CueMix on the host system. You can set an access password here (to stop rogue states ruining your foldback mixes), and it’s also possible to control multiple UltraLites from the same device. You can give your UltraLite a unique name in the Device tab, to make it easier to keep track of which interface you’re controlling.

If you’ve been interface shopping lately, you may have noticed that the new AB mode, talkback and remote control facility are remarkably similar to those offered by the newly launched 828, and in fact MOTU say that they were originally developed for the 828 before being ported to the UltraLite. That such useful features have been added to a product years after its initial launch bodes well for the UltraLite’s longevity and continued support, I think.

In Use

In practice, using the UltraLite Mk5 is a pleasure. The encoders feel sturdy and affirmative in action, the screen is bright and clear, and the menu options are self‑explanatory. The physical format lends itself well to being housed in a rack, but perhaps less so for desktop use. Given the DSP and mixing on offer, and now the monitor control features, a ‘desktop wedge’ version with buttons and a larger volume encoder on the top would be great — but would also render it unrackable, so I can see why they’ve opted to put all the controls on the front.

Speaking of monitor control, while the AB mode is most welcome, I’d also appreciate mono and mute switching. MOTU say that these should be simple to implement, though, so another firmware/CueMix update might soon oblige.

The CueMix mobile app worked perfectly on my iPhone 14 Plus for controlling the UltraLite remotely, with changes on the hardware reflected instantly in the app and vice versa, although the app was obviously designed with iPads in mind, so a fair bit of scrolling is necessary to find the channel or parameter you’re looking for, and landscape orientation is pretty much a must. That said, adjusting EQ and compression settings worked well using all the usual tap/drag/pinch gestures. Finally on the iOS app, CueMix does let you use your phone for level control and monitor switching, but on the iPhone at least, it isn’t especially touchscreen‑friendly. A redesigned monitor control section, or perhaps even a dedicated monitor control app (with mono and mute switching!) would completely eliminate my need for hardware monitor control. Again, when I put this to MOTU they said they liked the idea, so perhaps we’ll see it implemented in the future.

The excellent converter quality and monitor switching make it a more than valid choice for in‑the‑box mixing and mastering...

As for who the UltraLite Mk5 might be for... Well, the excellent converter quality and monitor switching make it a more than valid choice for in‑the‑box mixing and mastering, while the ADAT I/O means it can be expanded to cover hybrid hardware mixing setups and multitrack recording scenarios. Its 10 line outputs and Monitor Group functionality make it capable of playing 7.1.2 or 5.1.4 Atmos (or any of the common 2D surround formats), and the DC‑coupled outputs could see it equally happy nestled among a tangle of modular patch cables. The ability to connect to mobile devices as well as computers only adds to that versatility, as does its compact form factor and WiFi control option.

One indication of who MOTU think the UltraLite Mk5 might be for is the fact that they sell a rackmounting kit for housing two UltraLites in 1U. But why would you want two identical audio interfaces? Well, if you’re the musical director of a live show that Can’t Go Wrong, a redundant setup is pretty much a must, so having a second UltraLite to fall back on should the first fail would be a significant comfort. And thanks to CueMix’s ability to control multiple interfaces from a single device, switching to your backup UltraLite would be the work of seconds.

In short, then, unless you simply need more I/O than the UltraLite can provide, it should fit almost any workflow imaginable.