Universal Audio makes some of the best audio interfaces you can buy — both for your home studio and for commercial studio environments.
The company makes everything from high-end commercial-grade rack-mounted audio interfaces down to small to medium desktop audio interface devices. And anywhere on the spectrum, you’re getting legendary quality and power.
Every Universal Audio interface comes equipped with the company’s superb build quality and its legendary unison preamp. Each unit also ships with one or more powerful DSP processing cores, allowing you to run UAD Powered Plug-ins natively on the hardware.
On this blog, we’ve already published an overview guide to the entire Universal Audio family of audio interfaces, plus an in-depth review of the most popular option, the Apollo X Twin. So if you haven’t seen those posts yet, you might want to check them out before continuing.
Today’s post focuses on the smallest and least expensive audio interface in the Apollo family: the Apollo Solo (known until just recently as the Apollo Arrow or the UAD Arrow). Is this diminutive audio interface worth the investment? What does it offer that lesser brands don’t? And what does it leave out that the bigger and more expensive UAD interfaces include?
We’ll answer those questions and more below in A Music Producer’s Review of the Universal Audio Arrow / Solo Audio Interface.
UAD Apollo Solo / UAD Arrow: An Overview
If you’re a beginner who is just getting into home studio recording or if you otherwise haven’t heard of the brand, there are some things to know right off the bat. Universal Audio is not a budget oriented brand, and they don’t make entry-level devices. So, while the UA Solo is technically UAD’s entry-level option, don’t make the mistake of assuming it has an entry-level price tag.
The Apollo Solo is a compact, feature-light audio interface, and it still costs $699. Now, stick with us: there are plenty of really, really good reasons you might spend this much on an interface (even though you can get a true entry-level audio interface for well under $200). We just want to make it clear up front what ballpark we’re in.
Now, with that out of the way: the UA Solo is the least expensive way to get into the UAD system. Here’s what you get in a UA Solo.
Inputs and Outputs
The UAD Apollo Solo is a 2 x 4 audio interface. The two inputs are both combination XLR and quarter inch jacks, and both inputs are equipped with the legendary Unison preamp (more on the preamp later). There’s also an instrument-level quarter-inch input on the front of the unit, but this is not a third input. If you use the front input, it overrides the first rear input.
As far as outputs, this audio interface offers left and right quarter-inch outputs for you are monitor mains. There is also a quarter-inch headphone jack on the front and a Thunderbolt 3 / USB-C port for connecting to your computer. (There’s also another model that uses USB 3 along with a separate power port, if you’re dealing with a piece of hardware that supports USB 3 but not Thunderbolt 3.)
A 2 x 4 audio interface is fairly standard for entry-level interfaces, but it’s worth comparing I/O on the Solo to I/O on the Apollo Twin X at this point. The larger Twin X adds a second set of monitor outputs on the back, plus an optical port that can accept either ADAT or S/PDIF. Over ADAT, you can add another eight inputs using an eight mic pre.
So, out of the box, the only immediate difference between the two is the additional outputs on the Twin X. But if you need input expandability either now or down the road, the UA Solo doesn’t have it. The Twin X does.
As is typically the case across many brands, you can find a number of special editions for many of these interfaces. The version we’re recommending is the Apollo Solo Heritage Edition, which includes a set of five award-winning plug-in bundles valued separately at $1,300. These UA plug-in bundles include plug-ins from Teletronix compressors and Pultec EQs, among many more.
Access to UA plug-ins is one of the primary reasons to buy into the UAD Apollo line, so getting some of them free of charge is a great bonus.
The front hardware interface on the UAD Apollo Solo is nearly identical to the one on the Apollo Twin X and Apollo x4, with a few key differences.
This gorgeous hardware interface offers you a controllable dial, usually used for setting gain levels. You’ll see gain indicators for both inputs as well as for your monitor and headphone outputs. There’s a toggle for the Unison preamp and for monitor control, and then there’s a bank of six control buttons.
So far, everything we’ve said matches perfectly with the hardware interface on the more expensive models. The difference is in the bank of control buttons. On the Solo, these have single, dedicated functions. On the Twin X and x4, these buttons cover two functions each, giving you twice as much on-hardware control.
For example, the Twin X includes talkback control. The Solo doesn’t. (This makes sense, though — if you’re a solo artist, you don’t need to talk back to yourself.)
Solo DSP Core
I mentioned earlier that access to the UA plug-ins is one of the primary drivers for buying a UA Apollo audio interface. And that’s true — the plug-ins are deeply impressive. But there’s more to the story than the plug-ins alone.
What sets UA Apollo audio interfaces apart from most of the competition is the inclusion of digital signal processing (DSP) cores. These processor cores allow the interface itself to handle processing the UAD Powered Plug-ins you use in your sessions. Because of this, your computer’s own processor doesn’t have to shoulder this load. You also get potentially better sonic results thanks to the on-interface processing.
Really, it’s the combination of world-class plug-ins and superior on-device digital signal processing that makes a UA interface so special.
Now, what about the competition? Some entry-level and midrange audio interfaces offer on-unit DSP, but most don’t. And of the ones that do, none can match UA’s work in this price tier, especially with UA-designed plug-ins.
Legendary Unison Preamps Justify the Cost by Themselves
Those UA Powered Plug-ins and on-device processing are one half of what makes the Apollo family of devices so compelling. The other half? It’s the Unison preamps.
Now, if you’ve done any looking at audio interfaces already, including the inexpensive entry-level devices, it seems like every company and every reviewer it is touting this or that preamp as the best in its class or something like that. So it would be tempting to dismiss UA’s preamp as just another one in a crowded field — but that would be a big mistake.
UA’s Unison preamp is a world all its own: the sound and quality of the preamp itself are already a league above what you’d get in an entry-level device, but that’s only the starting place.
By using UA’s Console software, you can load up a wide variety of preamp plug-ins that can emulate mic preamps from Neve and API or guitar amp emulations from Fender and Marshall. And these aren’t just software emulations: they actually physically reconfigure Apollo’s impedance, changing the actual, physical output of the Unison preamp.
This level of control and precision — in an actual, physical preamp rather than in a software emulator — seems too good to be true. But this is one case where reality really does line up with theory.
The Unison preamp — and the ability to configure it with UA’s Console software — is so impressive, I’d say it’s worth the $699 price tag of the Apollo Solo, all on its own.
A/D and D/A Conversion
A/D and D/A conversion is another area that can be a sort of black box. Every audio interface on the market can do it, so it might seem like a commodity service, where every device does an equally good job at it.
But here again, Universal Audio puts that theory to rest. Apollo’s A/D and D/A conversion “sonically outperform anything in their class.” You get true pro-grade conversion that performs at the highest level.
This is the sort of thing that amateur musicians and listeners might not be able to identify right away. But it’s one of the elements that gives truly pro-grade music a distinctive edge or advantage over more cheaply produced tracks.
Deciding Between Devices
If you’re already sold on the benefits of the Universal Audio Apollo system, the next step is to decide between devices. These are the questions you need to answer for yourself as you work to decide which audio interface is right for you.
What Are Your Current (and Future) I/O Needs?
The most important question you need to answer as best you can is about your current and future input and output needs. Here, both the Solo and the Twin X offer two onboard inputs. That’s enough for singing and playing guitar simultaneously, or for tracking two isolated vocalists, or a host of other scenarios.
But if you ever think that you will need to expand to more than two simultaneous inputs, the Solo can’t do it. The Twin X can, with the right secondary piece of hardware.
You might not think this is likely, but there are more scenarios than you might think where you would need more than two microphones. If you ever want to track live drums, for example, most recording setups use at least five microphones.
The same goes if you ever want to do any live recording your band or even something like a jazz trio. Two microphones just aren’t going to cut it.
You need to ask similar questions about your current and future output needs. For a simple home studio, one pair of monitor outs is really all you’re going to need. But if you ever anticipate expanding into anything more complex, the Solo will limit you from doing so.
How Many DSP Cores Do You Need?
The biggest point of differentiation between the Apollo Solo (or Arrow) and the Apollo Twin X is the number of DSP cores. The Solo gives you one, whereas the Apollo Twin X gives you either two or four, depending on the model.
But how many do you really need? Sure, more is better, generally speaking. But how do you know exactly how much processing power you need?
The trouble is, how much processing power you need is kind of hard to define. How much processing power you need depends on a variety of constantly changing factors, including these:
- how many tracks you are processing
- the bit rate of those tracks
- the relative complexity of the plug-in or plug-ins that you’re using
- how many plug-ins you want to use at once
I wish I could give you a hard and fast answer, but there’s no one size fits all approach here. Of course, lesser brands don’t give you any processing cores, so one is certainly better than none. But try to think through your “worst case scenario,” the situation where you’ll be taxing that DSP core the most.
If you’re doing simple music using minimal processing, a solo core is probably more than enough. But as you add more and more tracks and plug-ins, you may want to consider moving up to a two- or four-core unit. If you record at a very high bit rate or want to use particularly resource-intensive plug-ins, you’ll probably do better with more cores.
One last bit of advice on this point: if you’re on the fence, err on the side of more power than you need, not less. You’ll spend a bit more up front, but you won’t be kicking yourself in a few months or years.
What’s Your Budget Like?
The last consideration is the most obvious. You need to look at your current budget and compare that to the cost of both interfaces. The Apollo Solo Heritage Edition lists for $879 and usually sells for $699, which is a lot of cash for an “entry-level” audio interface. (Though I hope by this point I’ve shown you why it’s worth the money!)
The Apollo Twin X Duo Heritage Edition, on the other hand, lists for north of $1300 and regularly sells for $1099. Want to step up to the Quad? The Quad Heritage Edition lists for $1999, often selling for around $1599.
So, it’s one thing for me to say that you should probably choose the Twin X because it offers more future expandability. It does, and you should, but leapfrogging into four figures is a pretty steep hurdle. If you don’t have the room in your budget, the Solo is still a great way to enter the world of UA hardware, plug-ins, and software.
Final Thoughts: Should You Buy a UAD Apollo Solo Interface?
Now that we’ve covered just about everything you should know about the Apollo Solo audio interface, it’s time to ask the final question: should you buy it?
As I mentioned just above, the first consideration is cost. Also, your end goals are a close second. Not every at-home musician is in a place to get into the UA ecosystem, and not everyone needs to. If you’re a hobbyist on a limited budget, any Arrow interface might well be overkill. Yes, you’ll get better results with one, but will the results be so much better that it’s worth going into debt for them? Probably not.
The same goes if you’re brand-new to at-home recording. You may well be better off starting with something simpler like a Focusrite Scarlett Solo. An interface like that is plenty capable for basic recording work like what you’ll probably be doing as you get your feet wet in the recording world.
Now, if you’re a hobbyist or a beginner with a comfortable enough budget, you can absolutely consider getting an Apollo interface. It may be more of a splurge the necessity, but you’ll definitely get impressive results with it.
If you’re serious about your craft or have intentions of going pro or selling your music for profit, investing in an Apollo device definitely makes sense. This is a competitive industry, and you need every advantage that you can get to make your sound stand out.
But Is the Solo the Best Apollo Interface for You?
Besides cost and goals, there’s one more question to ask: does the Apollo Solo make more sense than another more expensive Apollo device? In other words, is the Solo better than the Twin X?
For most people and most scenarios, the answer is no. The Apollo Solo is an absolutely fantastic audio interface. But the limits on expandability are hard to swallow, especially at this price. It’s impossible to predict the future, and limiting yourself to only two inputs forever is a difficult thing to recommend.
Even if you feel very sure that you’ll never need more than two inputs, do you want to be on the hook for a new, bigger interface if you end up being wrong about this?
So here’s the bottom line: You should probably buy the Apollo Twin X rather than the Solo. Greater I/O, not to mention double or quadruple the DSP power, make the Twin X much more flexible and much more powerful.
Most musicians who can afford a $699 interface can stretch a bit to afford a $1099 interface, and you’ll save money in the long term if you would’ve eventually needed to upgrade.
I can think of two, maybe three scenarios where the Solo is the better choice. First, if your budget prevents you from jumping up to the Twin X, the Solo is far superior to the competition. Second, the Solo makes a ton of sense as a backup or portable solution that’s part of an existing ecosystem of UAD devices and software.
Whichever interface you choose, you’re about to jump into a whole new level of at-home recording and engineering. Enjoy the power and flexibility of Apollo hardware, and don’t forget to have fun along the way!