Audio Interface Top 10 Checklist

You’re ready to connect your guitar to a computer.


MOTU ’s Audio Express is just one of many interfaces with
“instrument” inputs designed specifically for guitar.

You’re ready to connect your guitar to a computer. Cool! But first, you need an audio interface. This checklist will help you make the right choice.

Run, don’t walk, away from consumerlevel components. A computer’s internal sound chip, or a consumer sound card (e.g., SoundBlaster), aren’t designed for guitar. Pass.

Make sure there’s a “Guitar,” “Instrument,” “DI,” or “High-Impedance” 1/4" input. These don’t load down passive pickups. Boxes like the Waves/PRS Guitar Interface can drive a line level input from a guitar, but you might as well get an interface with this option built in.

Decide between FireWire or USB to connect the computer and interface. USB is rising, FireWire is fading. However, when you need mucho bandwidth (like high sample rates, or using lots of mics and direct inputs to record an entire rock band simultaneously), FireWire has a slight edge.

Consider adding a FireWire or USB card to your computer. You’ll often get better audio performance by inserting a PCI card with FireWire or USB ports into your computer (avoid combo USB/ FireWire cards), and dedicating it to audio applications. Use the motherboard connectors for mice, keyboards, printers, hard drives, etc. With FireWire, check the interface manufacturer’s website for approved FireWire chip sets, and ensure the card uses those chips.

Determine your other needs. Recording vocals? Look for at least one quality mic preamp. Think you’ll need more mic inputs eventually? Check for an ADAT optical input. Then you can use a device with eight mic preamps and an ADAT optical output (e.g., PreSonus DigiMax D8) to expand your system.

Bus-powered or not. For portable recording or onstage laptops, a bus-powered interface is more convenient. It gets its power from the computer, and doesn’t need an AC adapter.

Are your sample rates of choice covered. Not all interfaces (especially USB) can handle high sample rates, such as 96kHz. For most applications 44.1kHz or 48kHz is fine, but if you need high sample rates, check the specs to avoid disappointment.

Evaluate the freebies. Interfaces often bundle software-“lite” versions of DAWs, loops and samples, free plug-ins, etc. Some of this may just be bloatware you’ll never use, but sometimes bundles add serious value.

Direct monitoring: It’s a beautiful thing. Monitoring the computer’s output via your interface will have some delay due to the time required to process your signal. Direct monitoring monitors the interface input so you don’t hear any delay, with the tradeoff being that you won’t hear any processing (e.g., amp sims) added within the computer. Direct monitoring is particularly useful for drums and vocals, as they generally don’t require processing in the computer until mixdown.

Check for desirable “secret sauces.” A few examples: Roland’s VS-20 is designed specifically for guitar and includes a Boss hardware multi-effects in the interface. Line 6’s TonePort series comes bundled with POD Farm amp sim software. Native Instruments’ Mobile I/O is ultra-portable, and ideal for laptops. All other factors being equal, some of these special features might tip you toward a specific interface.