The Quartet USB 2.0 Audio Interface for iPad, Mac and Windows 10 with Lightning Connector Cable from Apogee is a four-input/eight-output USB 2.0 audio/MIDI interface, which when paired with an optional ADAT Lightpipe equipped expander, allows for streaming up to twelve channels of audio into an Apple computer, iPad, iPhone or iPod touch. It will also work with any PC that utilizes Windows 10 operating systems. It features four microphone preamps with 75 dB of gain and combo XLR/TRS inputs for connecting microphones, instruments, or line-level signals.

Two TOSLink optical inputs, besides providing the option of eight-channel ADAT Lightpipe input, when used together, support SMUX for higher sample rate audio transfer. The rear panel houses six analog 1/4" TRS line-level outputs, a Wordclock output, and dual USB ports. One USB port is for connection to the Mac or iOS device, and the other supports USB MIDI input and output. A USB to Lightning cable is included for connecting to Lightning connector iOS devices such as the iPhone5, iPhone5c, iPhone5s, iPad Air, and 2nd generation iPad Mini. A side panel 1/4" TRS jack provides independent headphone output.

The balanced 1/4" outputs allow for referencing audio on up to three separate sets of monitors. Three "QuickTouch Pads" with LED highlight rings above the main controller knob can be assigned to different functions, such as mute and sum-to-mono. They can also be used to switch the analog outputs on or off, facilitating sound comparison on different kinds of speakers. Two color OLED displays supply detailed metering and other information, including gain level, headphone volume, and phantom power status.

Apogee Maestro software for Mac, iOS, and Windows 10 provides low latency monitoring and control of Quartet. The unit features special circuitry that makes a direct digital connection to iPad and iOS devices and is certified by Apple's MFi (Made for iOS) program. The Quartet is also able to charge an iPad for uninterrupted recording and mixing. With hundreds of music apps for iOS and iPad available and plug-and-play functionality, making music on these portable devices is easier than ever.