When a Mac upgrade obsoleted my audio-interface's PCI card for the second time, I was persuaded to look for an external alternative. Even though this was for a desktop studio, my space was limited and my I/O needs were minimal—sound quality was everything. Reputation, along with its close relationship with Apple and integration with Logic, put Apogee high on my list and the Duet (Mac, $495 MSRP) offered both the connectivity and footprint I needed.

Fig. 1a-b: Apogee has reduced the Duet’s I/O to an absolute minimum.

My new Mac was set up and loaded with software waiting for a voice, so I called my local dealer, found they had one Duet on the shelf, and ran right over. Minutes later I had installed the Duet drivers and Maestro controller software (more on which later), restarted my Mac as required, and was ready to connect the Duet to the computer with the supplied cable. That's when I noticed that Apple had shot me in the other foot by abandoning Firewire 400 ports on my new Mac Pro. The Duet's port and cable were Firewire 400; however, with a converter you can use a Firewire 800 port, so ten bucks and another trip to the store for the converter had me in business. (Apogee subsequently provided a free converter cable, and now the Duet ships with both Firewire 400 and Firewire 400/800 cables.)

My previous interface (which shall remain nameless) was excellent, so I wasn't expecting a noticeable difference in sound quality. That was my first surprise; with headphones, my powered Genelec nearfield monitors, and my aging JBL 4311s, the sound was noticeably clearer, especially at the high end—almost like removing cotton from my ears. The second surprise was how convenient the Duet is to use. With a single rotary encoder that doubles as a pushbutton you know it will be simple, but ease-of-use is often another story.

Fig. 2: Apple Logic Pro offers a built-in control panel for configuring the Duet's inputs, output, display, and muting behavior.

Ins and Outs
All input and output, except for the headphone jack on the front edge, is accessed through a breakout cable that attaches with locking bolts to the rear of the unit (see Fig. 1a-b). The breakout cable sprouts six tentacles: four terminating in 1/4-inch TRS jacks and two leading to female XLR connectors. Each connector's rubber housing is embossed with text and a graphic depicting its purpose: left and right speaker outputs, instrument inputs 1 and 2, and phantom-powered mic inputs 1 and 2. The Duet is heavy enough to hold its own with the tentacles dangling from your desktop, but a good yank on a mic or instrument cable could pull the unit off the table. The Firewire jack is also on the back panel.

Although the Duet sports four input connectors, you can use only two inputs at a time: two line, two mic, or one of each. All I/O supports up to 24-bit, 96 kHz resolution, as set by either the audio application (your DAW, for example) or in the Mac's Audio MIDI Setup (for iTunes, for example). The large rotary encoder and LED array above it control and display all input and output levels. A quick push down on the knob switches its function, and a brief pop-up on your computer monitor shows its current mode. Alternatively, pushing down on the knob and holding for a couple of seconds activates muting, which you can configure to toggle between the headphone and speaker outputs or to simply mute one or both.

Fig. 3: The Maestro application's Level tab is where you choose input sources, output destination (using or bypassing the Maestro mixer), and levels.

One of the Duet's most convenient features is that when the unit is set as the Mac's Default Output (in Audio MIDI setup), the Duet's output-level settings are simply applied to the Mac's Default Output level. So, when you have the Duet's rotary encoder managing some other parameter, you can use the Mac's keyboard (alternate F10, F11, and F12 keys) to control muting and the master output.

Fig. 4: Maestro's Advanced tab controls muting behavior, metering options, and the assignment of up to four MIDI controller modes for the Duet's rotary encoder.

Maestro, Please
The configuration of each of the inputs, how muting works, the setup of up to four MIDI controllers, and metering options are managed with the included Maestro software. Some of these settings are duplicated in custom Duet control panels integrated into Logic Express, Logic Studio, and Garageband (see Fig. 2). The software includes an optional mixer for combining the hardware inputs and software output. When disabled, your software application's output is routed directly to the Duet's hardware outputs, bypassing the mixer. Aside from creating, loading, and saving alternative setups and using the mixer, you need not run the Maestro software—it's not required for day-to-day operation.

The Maestro control panel has Level and Advanced tabs. The Level tab is where you configure the I/O (see Fig. 3). Each input can be set for XLR Mic (with or without phantom power), XLR Line (+4 dBu or –10 dBV), or the 1/4-inch instrument input. A handy Phase checkbox lets you reverse the polarity of the input. You can select Line or Instrument Amp for the output. Line gives you 0 to –64 dB attenuation at –10 dBV; whereas Instrument Amp gives you a fixed –20 dBV output.

The Advanced tab is where you configure muting and LED meter display mode (see Fig. 4). For muting, you get checkboxes to set the state of the main and headphone outs for mute-on and mute-off. You can have the LED display follow the function of the rotary encoder or always show the input or the output. Finally, you can activate as many as four MIDI states and set each to send MIDI controller or song position data (if your DAW supports that).

I haven't used the Duet with a laptop, but clearly it is designed with that market in mind, although being Firewire powered might limit your computer’s battery life. With headphones and no external input, you can dispense with the breakout cable. The optional MIDI routings for the rotary encoder would be most useful for laptop work in which you have no other MIDI controllers. And, its small footprint (4-inches W x 1.5-inches H x 6.3-inches D) and optional carrying case ($24.95) will be welcome on the road.

Whatever the context, the Duet is worth considering for its superb sound and well-thought-out design.

Pros: Superb sound. Easy to set up and use. Small footprint. Firewire-bus powered.

Cons: No Firewire 800 port.

Len Sasso is a freelance writer specializing in music technology. For an earful, visit his website, swiftkick.com.