The Scarlett 8i6 ($299) and 18i6 ($399; reviewed here) are two new USB 2.0 audio interfaces from Focusrite, and they differ only in their respective number of analog and digital line inputs (eight and 18, respectively). Both half-rack units feature two XLR Combi jacks for either microphone, line, or high-impedance DI inputs that use Focusrite preamps for up to 60dB of gain. Both units provide up to six simultaneous audio output channels.

The units have MIDI In/Out jacks and 24-bit/96kHz AD/DA converter chipsets, and are compatible with any DAW, including Pro Tools 9, by way of the included Focusrite Scarlett MixControl software--a virtual 18x6 DSP mixer that operates in 32 or 64-bit modes in Windows 7, Vista and XP SP3, or MacTel computers running OS 10.6.5 Snow Leopard.

A quick pop of the hood of the steel-cased 18i6 reveals a main circuit board surrounded by subassemblies for the front and rear panel controls and jacks. Most all components are surface-mounted and contribute to the unit's overall ruggedness. Power comes from an included, lightweight 12-VDC wall-wart supply that comes with adapters for plugging into any AC wall outlet in the world.

The 18 inputs comprise two Focusrite mic/line/instrument inputs with gain controls and, on the rear panel, six balanced analog line inputs, an ADAT Lightpipe for eight more digital inputs (four at 88.1/96 kHz), and a stereo S/PDIF input. The unit's six outputs comprise two balanced monitor line outputs with level control; a stereo headphone output jack that is separate from the monitor output, with its own level control; and a S/PDIF stereo output.

The front panel has three green LEDs to indicate power, USB connectivity and system sync lock. Two red LEDs indicate that you have selected, in MixControl, whether the Focusrite pres are high impedance instrument inputs or low impedance mic/line level. A set of eight, green and red LED trees indicates input signal presence and/or clip at any of the eight analog inputs.

MIXCONTROL DSP MIXER/ROUTER

MixControl software routes and mixes up to 18 input sources with a latency specified at lower than 1.4 ms. The Mixer section has nine stereo faders and a stereo master fader; each can unlink (split) into two mono faders. In either mode, each has a pan pot plus mute, link/unlink, solo, and PFL buttons. Input sources from the eight analog, 10 digital inputs and six outputs from your DAW are selectable via pull-down menus with the already selected sources grayed out.

The master fader is assignable for either stereo or mono mix channels for up to six mixes total (a stereo mix uses two channels). You can rename, save and copy mixes for quickly creating amended versions of your main monitor mix for alternate mixes and/or headphone mixes.

The wholly separate Routing section is for connecting audio sources directly to any of Scarlett's six physical outputs, and it works globally across all saved Mixer configurations. The Zero Latency mode routes a mix developed in MixControl's stereo mixer directly to the monitor and headphone outputs, but you can also easily change over to listening to your DAW's mixer.

The Monitor Control section has an onscreen volume control, mute, dim, and Left or Right mute buttons. These virtual controls drive the front panel controls, so you can control the level of both the monitor speakers and the headphones together or independently. You can also elect not to control monitor level and output full level to an external monitor controller.

The Device Status Section indicates sample rate, sync source/status--internal or external coming in on the S/PDIF or ADAT Lightpipe--and USB connectivity. For Windows users, there is a pull down menu for selecting the ASIO buffer size here.

INSTALL, CONFIG, PLAY

After installing the software, I connected to Scarlett a USB cable from one of the rear sockets of my computer; an ADAT Lightpipe output from my Focusrite OctoPre MkII; two 1/4-inch monitor output cables from Scarlett to my KRK Ergo monitor controller; and the S/PDIF out from my CD player into the Scarlett's S/PDIF in--that was for playing CDs directly in the MixControl mixer, although I would have to change the sync source over to the CD player.