Apogee Duet 3 – third generation of the American bestseller

Maxim Liadov

Since 2007, the compact external Duet interface has been one of American company Apogee's best-known products and bestsellers. The third-generation Duet 3 retains its predecessors' strengths. It is attractive and easy to carry, with a convenient large level knob and multi-segment meters. High studio sound quality sets it apart from typical devices in this format. A new onboard DSP adds hardware effects, making audio ready for tasks such as online broadcasting. As with the Symphony Desktop, Symphony ECS Channel Strip processing from renowned engineer Bob Clearmountain is included. The Duet 3 is not cheap, targeting demanding professional musicians and experienced content creators.

Can a recording interface limit creativity? Will better equipment improve the music? For beginners, probably not, so entry-level mainstream products are a sensible start. They also help users learn which functions they need. As skills develop, equipment becomes more important. A creative mindset matters too: professionals benefit from thoughtful, high-quality studio tools suited to their abilities. Those tools should not be bulky or difficult. The Duet 3 aims to meet these needs.

Its appearance is more futuristic. The thinner Duet 3 has a glass top that looks expensive but shows fingerprints. A plastic disc around the level knob avoids visible finger marks and has switchable lighting.

The entirely rubber-covered underside holds firmly on a desk, allowing one-handed adjustment. The knob controls speaker volume, headphone volume and input gain. Pressing it changes the active function, shown by HP, SP, IN1 or IN2 indicators. FX1 and FX2 light when hardware effects are active. Holding the knob for a couple of seconds enables MUTE and makes the current function indicator flash.

Photos exaggerate the attractive meters' brightness. In reality, tinted glass reduces LED light considerably, so maximum brightness is modest. Settings can dim it further.

Meters remain visible in daylight, but we would prefer them brighter, as in the advertising. Firmware may address this, though preference is personal. Bright meters are easy to see from a distance during recording and look impressive. However, hours of flashing LEDs at the edge of vision can become tiring. Music work needs concentration, so brightness should be balanced against distraction.

Apogee Duet 3 features

• 2 preamps
• 2 inputs × 4 outputs
• USB Type-C connection
• Low-profile aluminium case
• Scratch-resistant glass
• Large illuminated volume knob
• I/O through a detachable breakout cable
  • 2 TS guitar inputs
  • 2 XLR microphone/line inputs
  • 2 balanced TRS line outputs
• Mini-jack headphone output
• Hardware DSP with Symphony ECS Channel Strip FX
• USB bus power
• Extra USB Type-C port for power when needed
• macOS and Windows 10 compatibility
• Optimized for Apple Logic Pro X and compatible with DAWs
• Optional Duet Dock
• Hard travel case for Duet 3 and soft cable pouch

The key Duet 3 specification is 2 combined microphone/guitar/line input channels and 4 independent output channels, serving monitors and headphones.

Apogee promises legendary recording quality, but numerical specifications are absent from the product page and manual. They are hidden deeper in the website in this useful table.

Parameter	Symphony Desktop	Duet 2	Duet 3	Element 88	Ensemble TB
Preamp gain	75 dB	75 dB	65 dB	75 dB	75 dB
Input THD+N	-114 dB	-106 dB	-103 dB	-110 dB	-110 dB
Input dynamic range	123 dB	114 dB	119 dB	119 dB	119 dB
Maximum input level	20 dB	20 dB	18 dB	20 dB	20 dB
Output THD+N	-114 dB	-113 dB	-110 dB	-114 dB	-114 dB
Output dynamic range	129 dB	123 dB	124 dB	123 dB	123 dB
Maximum output level	20 dB	20 dB	18 dB	20 dB	20 dB
Headphone output THD+N	-111 dB	-110 dB	-109 dB	-107 dB	-109 dB
Headphone output dynamic range	129 dB	123 dB	124 dB	117 dB	120 dB

All figures are high, suggesting top-level electronics. In comments accompanying the table, Apogee explains that although some numbers may not look dramatic, this is a new design. The headphone output has changed significantly, with a stated 0-ohm impedance and improved sound.

An Apogee representative says the aim was maximum simplicity. Connect the interface to a laptop USB port and start working. For headphone use, no breakout cable is needed because the socket is on the front. The 1.5-metre breakout cable is long enough to hide connections behind a monitor or farther from the desk. This suits users who often travel with the interface for headphone listening. Disconnect the Duet 3, take it along, then reconnect one plug in the studio to resume work.

Users who dislike that arrangement can buy the optional Duet Dock. It removes the breakout cable and gives the familiar connections of a normal USB interface.

The dock includes a full-size TRS headphone output absent from the standard breakout cable. A second USB-C socket supplies extra power when connected to a USB 2 port. A higher-current USB 3 connection needs no extra power.

A hard zippered case is supplied for Duet 3 transport and storage.

It has separate spaces for the Duet 3 and cables, with cables held in a zippered fabric pouch. This attention to users is another advantage.

ASIO diagnostics

Separate channels 3/4 allow a dedicated headphone submix from the DAW, or laptop-based DJ use.

Latency is 7.5 ms with a 64-sample buffer at 44 kHz. This is normal for USB 2.0 interfaces, especially with a hardware mixer.

Drivers support macOS and Windows 10 and 11. An advanced panel provides a mixer and meters.

The panel resembles Symphony Desktop and other new-series interfaces. All settings appear in one window without tabs. Unneeded channels can be hidden. Microphone inputs offer phantom power, linking, polarity inversion and a Soft Limiter with a -4 dB soft threshold to prevent ADC overload. Headphones can follow speakers, receive DAW channels 3/4 or monitor inputs. Monitoring can be dry or use hardware effects. The mixer signal can also return to recording, useful for online broadcasts. It is well considered and convenient.

Some online users complain that they cannot monitor processed audio while recording a dry signal. That function is planned for later. Hardware effects are central to 5 Apogee interface models, so development is fast and software updates are frequent. We will follow further changes.

The included Symphony ECS Channel Strip hardware plug-in was developed with Grammy-winning engineer Bob Clearmountain, who has worked with the Rolling Stones, Bruce Springsteen, Bon Jovi, Bryan Adams, David Bowie and Paul McCartney. He explains it in this video:

The plug-in combines a low-cut filter, parametric EQ, a compressor with parallel compression and drive for warmth. It is easy to use and fairly gentle, without damaging the sound. Processing works in real time without adding signal delay, like an external hardware processor. For the same effect during DAW mixing, users can buy the matching software plug-in from Apogee.

We connected a professional studio microphone, the Neumann TLM 103 and recorded with processing on and off. We think the plug-in offers enough for live use. It makes sound denser, useful for online speech, vocals and acoustic guitar. Recording quality itself is excellent, matching top studio products. For DAW use, the plug-in is a personal choice: EQ and compression alternatives are plentiful.

Other plug-ins are listed on the FX Plugins page on Apogee's website. Hardware DSP versions carry the FX Rack label, while AU/VST/AAX versions are marked Native. Most plug-ins have both badges. Users can download trials, buy plug-ins or rent them for a project. We found no hardware reverb or delay yet, but Apogee promises to expand the range.

RightMark Audio Analyzer test report

Device under test	[ASIO] Apogee USB ASIO Driver
Operating mode	24-bit, 44 kHz
Signal path	External loopback (line-out - line-in)
RMAA version	6.4.5 PRO
20 Hz–20 kHz filter	YES
Signal normalization	YES
Level change	0.0 dB / 0.0 dB
MONO mode	NO
Calibration signal frequency, Hz	1000
Polarity	Correct/correct

Frequency response variation (40 Hz–15 kHz), dB	+0.06, -0.06	Excellent
Noise level, dB(A)	-120.4	Excellent
Dynamic range, dB(A)	119.9	Excellent
Harmonic distortion, %	0.00133	Excellent
Harmonic distortion + noise, dB(A)	-94.7	Very good
Intermodulation distortion + noise, %	0.00166	Excellent
Stereo crosstalk, dB	-120.6	Excellent
Intermodulation at 10 kHz, %	0.00236	Excellent
Overall rating		Excellent

Detailed microphone-input measurements at 24-bit/44 kHz

Loopback measurements combine input and output performance. Dynamic range is very high. Distortion is higher than usual because there is no dedicated line input: the signal always passes through the preamp. The panel's line mode effectively selects microphone input with fixed minimum gain. This is a minor issue, since true line inputs are rarely needed in this class. External microphone preamps would conflict with the all-in-one concept and onboard processing. Users mainly need microphone and guitar preamps, which the Duet 3 handles very well.

Device under test	[ASIO] Apogee USB ASIO Driver
Operating mode	24-bit, 44 kHz
Signal path	External loopback (line-out - line-in)
RMAA version	6.4.5 PRO
20 Hz–20 kHz filter	YES
Signal normalization	YES
Level change	0.0 dB / 0.0 dB
MONO mode	NO
Calibration signal frequency, Hz	1000
Polarity	Correct/correct

Frequency response variation (40 Hz–15 kHz), dB	+0.05, -0.09	Excellent
Noise level, dB(A)	-115.7	Excellent
Dynamic range, dB(A)	115.6	Excellent
Harmonic distortion, %	0.00087	Excellent
Harmonic distortion + noise, dB(A)	-97.5	Excellent
Intermodulation distortion + noise, %	0.00168	Excellent
Stereo crosstalk, dB	-113.7	Excellent
Intermodulation at 10 kHz, %	0.00239	Excellent
Overall rating		Excellent

Detailed guitar-input measurements at 24-bit/44 kHz

Readers often ask us to measure guitar inputs too. Here are the results. The guitar input accepts a high +12 dBu level, allowing recording of passive pickups with strong peaks.

Conclusions

A simple Duet 2 update would have been understandable, but Apogee has redesigned both appearance and electronics. Duet 3 adds useful hardware DSP processing and an optional dock for users who dislike breakout connectors.

At the time of writing, the Duet 3 costs 55000 rubles. This is attractive because RME and other competitors with similar size, channel count and converter quality cost significantly more. Also consider the larger two-channel desktop interface, the Apogee Symphony Desktop, which also has hardware DSP, dedicated TRS line inputs and higher specifications. The trade-offs are a much larger case and the need for an AC power adapter. Duet 3 needs no power supply, is more portable and stylish, and includes a travel case. The Symphony Desktop is better suited to permanent studio use but also costs significantly more.

Note. This is an adapted machine translation into English. It follows the “In simple terms” approach. Read the original article at https://prosound.ixbt.com/interfaces/apogee-duet-3.shtml.