Audio / Hands-on Review

Immediate Appeal: Hands-On Review of the Universal Audio Apollo Twin


Universal Audio is one of those companies that do not need much of an introduction. An industry stalwart with a history that reaches back to recording’s adolescence in the late 1950s and ’60s, its history is firmly rooted in the analog realm, with legacy products such as the 1176LN limiting amplifier and the LA-2A leveling amplifier (both studio staples to this day). Nonetheless, Universal Audio has managed to not only remain relevant in 2014, but thanks to the company’s UAD-2 plug-ins and DSP accelerators, it’s one of the most important players in the digital age of music. Unlike many plug-in manufacturers, the UAD line requires one of Universal Audio’s UAD DSP Accelerators, and will not run natively on your computer.

Building on the success of the UAD-2 line of plug-ins, the company introduced the Apollo audio interface in 2012. Designed to provide you with professional quality analog to digital and digital to analog conversion, as well as a built-in UAD DSP Accelerator, interfaces in the Apollo line give you the ability to use UAD plug-ins in your mix while providing the added functionality of tracking through them, latency free, with the option of printing the effect or merely monitoring through it. Since the UAD plug-ins have always been designed and marketed as a way to get that “analog sound” back into your digital system, the Apollo, with its ability to track through those analog emulating plug-ins, had immediate appeal to professional and project studios alike.

Flashing forward to the 2014 Winter NAMM convention, Universal Audio announced a new addition to the Apollo family: the smaller form factor, desktop-friendly Apollo Twin. The Apollo Twin sports two combination XLR/TRS inputs that support line or mic level sources, as well as a front-panel 1/4" Hi-Z input for guitars and bass. The interface comes in two versions, The SOLO and the DUO, which come equipped with one or two UAD processing chips, respectively.

However, the appeal of the Apollo Twin is not limited to those who do not need the I/O firepower of the earlier-mentioned rackmount versions. With the Twin, Universal Audio debuted its Unison microphone preamp technology, for modeling classic vintage mic preamps (a feature that came to the Apollo Quad through a later firmware update). Rather than simply emulating sound and behavior in the digital domain, Unison technology changes the impedance, gain staging, and “sweet spot” of the hardware preamps, based upon which vintage UAD plug-in you have selected.

He’s Got the Apollo Twin SOLO in His Hands

I was lucky enough to get my hands on an Apollo Twin SOLO, the model of the Twin line that features a single Sharc chip for UAD plug-in processing. First, let’s look at how it connects to your computer, and what kind of computers it can connect to. The original Apollos were one of the first audio interfaces to employ Thunderbolt connectivity, and the Twin tows that line. While that means the interface benefits from the speed and convenience of Thunderbolt I/O, it also means that Windows users are out of luck. The interface is Mac only, and at the time of this writing, Universal Audio does not have plans to support any version of Windows. Also, it should be noted, a Thunderbolt cable is not included in the box, so you will have to pick up your own.

The Apollo Twin has a brushed-aluminum finish that matches the look of the modern MacBook. Its 12-volt power adapter includes a handful of international attachments, so if you travel internationally, you should be in good shape to bring this guy with you without too much hassle. When connecting the power adapter to the Twin, you have to insert and twist it into place, a clever feature that will help assure your power cable does not get yanked accidentally from the back of the device.

Control-wise, the Twin is straightforward. It features a single knob control, along with a Preamp button, and a Monitor button. With Preamp selected, pressing down on the knob will switch control between the two available input channels, while a press of the button with Monitor selected toggles control between your headphone output and the 1/4" TRS connectors running to your speakers. Along the bottom are a series of buttons to toggle on all the typical controls you would find on your average mic preamp: engage low-cut filter, 48 volts, pad, phase flip, and stereo link.

The Console Software and UAD Processing, or How I Learned to Stop Worrying and Love the UAD Meter

To fully exploit what the Apollo offers you, you will have to install both the UAD plug-in software and Universal Audio’s Console software. As its name implies, the Console software looks just like a traditional recording console, providing channel faders for your analog and digital inputs, as well as two auxiliary channels for monitoring reverb or other effects. The Console software is where you select which of the UAD Unison vintage mic preamps you wish to employ (if any), as well as any other UAD plug-ins you might wish to track through. This is also where you select whether you are simply monitoring through these effects, or applying them permanently to the audio you are about to record.

Console Software

All of my recordings for this review were done in Logic Pro X. To rely on the Apollo Twin for latency-free recording, you do need to make sure “Software Monitoring” is de-selected in your respective DAW, otherwise, you will hear a doubling of your audio―what you are recording is being played through the Console software and your DAW simultaneously.

The Twin comes bundled with a selection of UAD plug-ins. Universal Audio includes only one of its Unison mic preamp emulations, the UA 610-B Tube Preamp, while the others are available for separate purchase. All UAD plug-ins come with a two-week free trial, so I decided to take advantage of that for this review, and installed every Unison preamp plug-in available at the time of writing, and tracked some audio through them all to evaluate just how different (if at all) the plug-ins are. Currently in the Unison lineup are the UA 610-A, the UA 610-B, the Neve 1073 Preamp and EQ, and the API Vision Channel Strip, each emulating its respective hardware influence.

When you install the Console software, the UAD Meter and Control Panel will come bundled, and it will be either your best friend or your worst enemy. It basically lets you know how much of the processing power of the Apollo Twin you are using at any given time. As I mentioned previously, all UAD processing takes place inside the Apollo Twin, not your computer, so the total number of plug-ins you can run during tracking or mixing is totally dependent on which version of the Apollo Twin you get (either the SOLO, with one chip, which I am testing, or the DUO, with twice the power). Another factor that dictates how your processing power is used up is which plug-ins you want to run, as not all UAD plug-ins consume the same amount of processing power. Out of the gate I will say this: if you are looking to be able to get your hands on as many UAD plug-ins for mix-down, skip right past the SOLO and look for at the DUO, or better yet, the rack-mounted QUAD.

To provide you with an example of how much processing power some of the newer UAD plug-ins require, on the SOLO, you can only have two instances of the Neve 1073 at a time, with one channel of it taking up a whopping 49 percent of your SOLO’s processing power. While that enables you to use that plug-in for both of the Twin’s inputs, you will really have to learn to budget which plug-ins you use if you want to throw that Neve EQ on a track during mix-down, because you will not have much processing power left for your other tracks. When mixing with UAD plug-ins, as I have done in the past, you quickly have to learn how to allocate your resources, so that UAD meter will get checked constantly to see if you can squeeze another few plug-in instances into your mix.

UAD plug-ins

I wanted to provide some examples of what many people will commonly be recording with the Apollo Twin, so I have tracked acoustic guitar, bass, and electric guitar through each of the available Unison emulations. Let’s take a look and listen to what came out.

Acoustic Guitar

The first test I set up for the Apollo Twin was acoustic guitar. As its two-input setup holds substantial appeal for the singer/songwriter, I thought the best place to start was one of the typical instruments of choice for that genre. I tracked the guitar (a Martin) at 44.1kHz/24-bit resolution, using a Miktek CV3 tube condenser microphone set to a cardioid polar pattern. I played simple chords, hoping to best accentuate the differences between the preamps by avoiding a busy recording. I started with no Unison plug-in selected, so you can hear the sound of the stock mic preamp, which is quite balanced and nice, if a little neutral (which stands to reason, since Universal Audio is betting you will get the color and sound via your Unison plug-in of choice).

First up is the UA-610A. I kept the EQ flat on this (as I did with all the plug-ins for the acoustic) so you can hear just how it alters the preamps tone. The UA-610A added a bit of depth as well as accentuated some of the natural boominess of the Martin, and only taxed the UAD meter 33 percent. Moving onto the UA-610B (which will also cost you 33 percent), I noticed a similar tone to the 610A, likely due to the similar topology, but with the high mids more present.

It took a bit of self-control not to tweak the EQ on the API Vision channel strip, but I kept it flat for a fair comparison. Like the UA-610s, once instance of the API will cost you 33 percent of your available processing on the SOLO. I thought the API really captured the fullness of the guitar without sacrificing transient response or seeming smeared; and felt that sonically it sits somewhere between the two different 610 plug-ins.

Finally, the Neve 1073. Fighting off the same urge I had with the API to tweak the EQ, I track it flat. As previously mentioned, the Neve will eat up 49 percent of your available UAD power. I thought the plug-in provided that little extra something special to the guitar; slight harmonic overtones, with plenty of body and detail. For my money, I would have gone with the 1073 to track this acoustic if I were recording a song or album. Check out the files to see how you think they stacked up.

Electric Bass

A natural test of a preamp’s sonic quality is the electric bass. It is common studio practice to track bass DI to complement a miked amplifier, and each of the hardware versions of the Unison plug-ins are solid choices for that application. Once again tracking at 44.1kHz/24-bit, I plugged a Warmouth jazz bass directly into the Hi-Z input of the Twin, and then made the rounds of the Unison preamps.

I was eager to hear what the UA-610s would do to my bass signal, as the hardware version has been one of my favorite bass DIs in the studio. To sweeten the sound a bit, I applied a 3dB shelf boost at 10kHz, available on the 610A. The results are punchy bass that didn’t sacrifice the low end roundness. Hitting the 610B, I found the low mids were in need of a little taming, so I dropped a gentle 1.5dB low shelf at 200Hz, and gave a little boost at 7kHz for some more punch. I felt the differences between the 610A and 610B were less pronounced than on the acoustic guitar, and both provided a great, usable DI sound that would excel at blues, rock, and especially R&B.

With the API Vision channel strip, I decided to really dive in and dial in an API bass tone. I set up the in-line compressor to gently tame some transients, and boosted at 50Hz, 180Hz, 1.5 kHz, and 12.5kHz. The end result was focused without sacrificing the bottom, and would be at home in a rock or funk track.

The Neve once again showed off the sonic characteristics of its namesake hardware unit, and with some very gentle nudging of its EQ (a very slight boost of its high shelf, and a gentle cut at about 4kHz, with the low cut engaged at 50Hz), I got a very pleasing bass tone that would be home in a wide variety of tracks. Unlike with the acoustic guitar, I did not find I had a clear, hands-down favorite from the bunch, but liked what each brought to the table, and would use any of them, depending on the kind of track. Give the files a listen to see what you think.

Electric Guitar

Though I do not often track electric guitar DI (at least without using some sort of amp emulation software), doing so can be a real time saver and, in many cases, possibly just what a track needs. In that spirit, I hooked up a stock Gibson Les Paul Studio to the Hi-Z input on the Apollo, and again put the Unison plug-ins through their paces (at the same 44.1kHz/24-bit resolution as all the other files).

As with the bass tracks, I tweaked what each plug-in had to offer, to hopefully dial-in a more amp-like sound. With the API Vision, I engaged a low cut at 30Hz, added a touch of compression to tighten up the sound, and boosted gently at 500Hz. The plug-in gave me some chimey, bell-like tones with nice response. Though I recorded a strummed part for comparison’s sake, I would go to a sound like this for picked parts and arpeggios.

With the UA-610s, I have to admit I found the results a bit on the disappointing side. Since they are based on the tube architecture of their hardware influences, I was expecting both the 610A and 610B to shine with the Les Paul, but I found the tone I got out of them to be a bit on the thin and anemic side. These might serve nicely for a single-coil guitar such as a Stratocaster or Tele, but I would go with other options if using humbuckers.

Finally, the Neve 1073. While I liked the results from the API Vision, the Neve provided a more convincing performance to my ears, giving some weight and depth right where I would be looking for it on cleaner-sounding electric guitar. I cut fairly aggressively at around 7kHz, and put moderate boost on the high shelf, which is a common EQ curve approach for electrics, and one that I think worked in this case, too. Have a listen for yourself.

The Takeaway

The Apollo Twin provides truly professional functionality for those looking for a desktop recording solution. I found it easy to work with once I understood the signal flow and how the Console software works with your DAW, and was able to get some great sounds without too much fuss. Thankfully, each plug-in comes with a number of presets, many designed by prominent recording and mixing engineers, to start as a jumping off point.

However, I was a bit let down with how quickly the newer Unison plug-in ate up the processing power of the SOLO chip. While it was powerful enough to record two channels simultaneously with whichever Unison plug-in you would like, you would not be able to get too many UAD plug-ins going for a multi-track mix, so if you are looking to have both tracking and useful mixing capabilities, I would steer you toward the Apollo Twin DUO, or reach for the rack-mount Apollo QUAD. Another consideration you should have is that of the cost of UAD plug-ins: on the Unison front, only the UA-610B comes bundled with the Twin; those Neve and API plug-ins would be additional purchases. For tracking and mixing applications, as with all Apollo interfaces, the Realtime Analog Classics Bundle is included. This sets you up with the legacy 1176SE/LN limiting amplifier plug-ins, the legacy Pultec Pro EQs,  the legacy LA-2A leveling amplifier, RealVerb Pro reverb, the CS-1 Precision Channel strip, and Softtube’s Amp Room essentials. 

With the Apollo Twin, you get a very serious interface that is a step up from some more entry-level recording devices. Its UAD functionality also gives you access to a wide variety of emulated analog gear that can help your home studio grow over time. The ability to change the flavor of your mic preamps so easily can be worth the price of admission alone, and is going to make returning my review unit all the more difficult.

I/O 2x Combo XLR/TRS mic/line inputs
1x 1/4" (6.3mm) Hi-Z input
2x 1/4" (6.3mm) TRS balanced line outputs (independent mix buses)
2x 1/4" (6.3mm) TRS balanced (one stereo pair, independent L/R mix buses)
1x 1/4" (6.3mm) TRS unbalanced stereo headphone output (independent L/R mix buses)
1x TOSLINK optical, ADAT or S/PDIF selectable digital input
1x Thunderbolt port, Thunderbolt 2 compatible
Conversion Supported Sample Rates: 44.1, 48, 88.2, 96, 176.4, 192 kHz
Bit-Depth per Sample: 24-bits
Simultaneous A/D Conversion: 2 channels
Simultaneous D/A Conversion: 6 channels
Analog Round-Trip Latency: 1.1 ms @ 96 kHz
Analog Round-Trip Latency with 4 Serial UAD Powered Plug-Ins via Console Application: 1.1 ms @ 96 kHz
Analog I/O
Line Inputs Line Inputs 1 & 2:
Jack Type (combo mic/line balanced inputs): 1/4" (6.3mm) female TRS balanced
Dynamic Range: 117.5 dB, A-weighted
Signal to Noise Ratio: 117.5 dB, A-weighted
Total Harmonic Distortion + Noise: -108 dBFS
CMRR: Greater than 60 dB (10' cable)
Frequency Response: 20 Hz to 20 kHz, ±0.1 dB
Input Impedance: 10 kΩ
Gain Range: +10 to +65 dB
Minimum Input Level (@ Minimum Gain): 18 dBV
Maximum Input Level (@ Maximum Gain): -37 dBV
Stereo Level Balance: ±0.05 dB
Microphone Inputs Microphone Inputs 1 & 2:
Jack Type (combo mic/line balanced inputs): Female XLR balanced (pin 2 positive)
Phantom Power: +48 V, switchable per input
Dynamic Range: 118 dB, A-weighted
Signal to Noise Ratio: 118 dB, A-weighted
Total Harmonic Distortion + Noise: -110 dBFS
Equivalent Input Noise: -127 dB
Frequency Response: 20 Hz to 20 kHz, ±0.1 dB
CMRR: Greater than 70 dB (10' cable)
Default Input Impedance: 5.4 kΩ (variable via Unison preamp model)
Gain Range: +10 to +65 dB
Pad Attenuation: 20 dB (variable via Unison preamp model), switchable per input
Maximum Input Level (@ Minimum Gain, with Pad): 23.8 dBV
Maximum Input Level (@ Maximum Gain, with Pad): -31.2 dBV
Hi-Z Input Jack Type: 1/4" (6.3mm) female TS unbalanced
Dynamic Range: 117 dB, A-weighted
Signal-to-Noise Ratio: 117 dB, A-weighted
Total Harmonic Distortion + Noise: -101 dBFS
Frequency Response: 20 Hz to 20 kHz, ±0.1 dB
Input Impedance: 1 MΩ
Maximum Input Level (@ Minimum Gain): 10 dBV
Maximum Input Level (@ Maximum Gain): -45 dBV
Line Outputs Line Outputs 3 & 4:
Jack Type: 1/4" (6.3mm) female TRS balanced
Dynamic Range: 118 dB, A-weighted
Signal-to-Noise Ratio: 118 dB, A-weighted
Total Harmonic Distortion + Noise: -107 dBFS
Frequency Response: 20 Hz to 20 kHz, ±0.1 dB
Stereo Level Balance: ±0.05 dB
Channel Separation: Greater than 120 dB
Output Impedance: 600 Ω
Maximum Output Level: 18 dBV
Monitor Outputs Monitor Outputs 1 & 2:
Jack Type: 1/4" (6.3mm) female TRS balanced
Frequency Response: 20 Hz to 20 kHz, ±0.1 dB
Dynamic Range: 115 dB, A-weighted
Signal-to-Noise Ratio: 115 dB, A-weighted
Total Harmonic Distortion + Noise: -105 dBFS
Channel Separation: Greater than 118 dB
Stereo Level Balance: ±0.05 dB
Output Impedance: 600 Ω
Output Gain Range: -96 to 0 dB
Maximum Output Level: 18 dBV
Operating Reference Level: +14 dBu, +20 dBu (selectable)
Headphone Output Stereo Headphone Output:
Jack Type: 1/4" (6.3mm) female TRS stereo, unbalanced
Frequency Response: 20 Hz to 20 kHz, ±0.1 dB
Dynamic Range: 113 dB, A-weighted
Signal-to-Noise Ratio: 113 dB, A-weighted
Channel Separation: Greater than 110 dB
Total Harmonic Distortion + Noise: -101 dBFS
Stereo Level Balance: ±0.11 dB
Output Impedance: 10 Ω
Output Gain Range: INF to 0 dB
Maximum Output Power: 80 mW into 600 Ω
Digital Audio I/O
S/PDIF Connector Type: Optical TOSLINK JIS F05 (shared with ADAT)
Format: IEC958
Supported Sample Rates: 44.1, 48, 88.2, 96 kHz
S/PDIF Input Channels: 2 (stereo L/R)
ADAT Connector Type: Optical TOSLINK JIS F05 (shared with S/PDIF)
Format: ADAT Digital Lightpipe with S/MUX
Supported Sample Rates: 44.1, 48, 88.2, 96, 172.4, 192 kHz
ADAT Input Channels @ 44.1, 48 kHz: 1 to 8
ADAT Input Channels @ 88.2, 96 kHz: 1 to 4 (S/MUX)
ADAT Input Channels @ 176.4, 192 kHz: 1 to 2 (S/MUX)
Clock Sources Internal, S/PDIF, ADAT (digital clock sync source conditional per selected digital input type)
Power Supply External AC to DC
Connector Type AC: Changeable blades (UL, VDE, UK, SSA, CCC)
DC: Male plug, 2.1mm x 5.5mm, center positive
Power Requirements  AC: 100 V to 240 V AC, 50 - 60 Hz
DC: 12 VDC, ±5%
Maximum Power Consumption 12 W
Operating Temperature 32 to 95ºF (0 to 35ºC)
Storage Temperature -40 to 176ºF (-40 to 80ºC)
Operating Humidity 20 to 80%
System Requirements
System Requirements Apple Mac with available Thunderbolt port
OS X 10.8 or 10.9
Internet connection to download software and authorize UAD plug-ins
Compatible VST, Audio Units, RTAS, or AAX 64 plug-in host application software
2 GB available disk space
Thunderbolt cable (not included)
Dimensions (W x H x D) 6.31 x 2.60 x 5.86" (160.2 x 66.0 x 148.8mm)
Depth, Chassis Only: 5.86" (148.80mm)
Depth, Including Knob & Jack Protrusions: 6.20" (157.40mm)
Weight 2.35 lb (1.06 kg)

Discussion 6

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Great review and nice to listen the sounds. Just waiting for my Apollo Duo to come next month and a UAD2-OCTO! 

Ok, It seems like a really great thing. My question is how to connect my Great Sound Module - Muse Research Receptor Pro + to it. See, so far, I've been using a hradware chain. Guitar, synth, bass (one after the other) into the Receptor, then signal goes to a Mackie Mixer, then to Tascam Neo 2488. Now, could I just plug the 2 lines from the sound module to UA Apollo Twin, and from there to the Mac laptop (or iMac, or whatever the Mac computer would be) ?

Thank you, really!

Have a great day

Crocs In Tears

Hi Bencho -

You may do exactly as you propose.  Eliminating the Mackie mixer and Tascam Neo 2488 will create a shorter, more direct, signal chain, offering a cleaner, quieter, noise floor - and a lot less cabling!

Please contact us via e-mail if you have additional questions:  AskBH@BandH.com

GREAT gear!

Hello Roy Yeager

I've been driving myself nuts reading every possible thing about this Apollo thing. It has to be great........ you just said it was.  I am going to buy one right now. Long time no see my old friend!

Thanks for this.

As an Apollo Quad owner and someone with a TWIN on the way, this is very infomative.  I will have to EQ out the upper mid rise if I use the 610B for my vidcast voice mic.  I use a Heil PR40 which sounds uncharacteristicly gravely thru my Mbox2 Pro and expect the TWIN will clean things up and give me the oppurtunity to record thru one or more of my UAD plugs.

Take it EZ,

Robert A. Ober