Mackie calls the inputs “highheadroom,” and they’re not kidding. It was nigh impossible to overdrive ’em with keyboards, even when I set the trims too high. The guitar button, which affects the left input of channel 1, gave the perfect boost to the passive output of my old Rhodes. The U420 also didn’t audibly pinch my sound — what went in, came out.
If something is plugged into only a left or right input, the U420 sensibly routes it to both stereo channels at the main and aux outputs. FireWire simply mirrors the main stereo mix — though you can record a stereo (or mono) track at a time, you can’t record things on separate U420 inputs to separate tracks in your DAW. Fair enough, because the U420 isn’t intended as a full multichannel audio interface. It is meant to let you record live sets to a computer, and at this, it’s brilliant. If your set includes soft synths on that same computer, a clever little button causes what’s coming out of the computer to be recorded back in.
FireWire audio coming into the U420 gets mixed to the main outs, but not the aux outs, and this can be an obstacle at a gig. A typical live setup is to feed the house P.A. from your keyboard mixer’s mains and feed an onstage powered monitor from an aux. Well, if you have soft synths on a laptop, you won’t hear them in your monitor. This is an odd omission, because this kind of setup seems to fit Mackie’s “keys junkie” customer to a tee. The headphone output does pick up the main mix, though, FireWire signal included.
Overall, the U420 delivers an excellent feature set for the price, and I’d recommend it to three sorts of non-cartoon characters: first, any electronic player looking for a “my first recording interface,” especially since you get the very cool Tracktion 3 production software (reviewed Aug. ’07) in the bargain. Second, anyone whose keyboard rig has outgrown the number of free P.A. channels at the local clubs. Third, desktop multimedia pros who make music for web productions — you folks in particular are most likely to find that anything bigger and more expensive is overkill, and that a U420 is exactly what you need.
PROS
Tons of gain and clean headroom. Grab-me main volume knob. FireWire looping records computer output back into computer. Inclusion of Tracktion 3 is a huge bonus.
CONS
No pan knobs. A bit noisier than higherend Mackie lines such as the VLZ3. No way to route FireWire audio to aux outputs.
INFO
$299.99/approx. $230 street,
mackie.comNEED TO KNOW
What is it? A keyboard/line mixer with four stereo channels and FireWire interfacing that goes up to 24-bit/96kHz.
How many keyboards can I plug in? Up to four in stereo. Plus, channel 1 has a gain switch for guitar-level signals, and channel 4 adds RCA inputs with a turntable preamp.
Does it take mics? No, but its sister the U420d has two mic inputs with phantom power.
Does it do MIDI? Nope, but the assumption that it doesn’t need to (because your computer and MIDI controller talk via USB) is a pretty safe one these days.