Instrument designer Roger Linn insists he created the first digital drum machine as a handy stand-in for a real drummer, never dreaming that his LinnDrum Computer would define the drum sounds of the '80s. And when he refined his ideas via Akai's MPC-series sampling sequencers, he had little inkling he was creating the near-universal groove tool of modern hip-hop. But with his new guitar gizmo, Linn knows exactly what he's doing-capturing a thrilling assortment of beat-synchronized stereo effects in a compact and reasonably priced stompbox.

By combining a digital effects processor with a drum machine, Roger Linn Design's AdrenaLinn Groove Filter FX + Amp Modeling + Drum Box ($395) unleashes head-spinning flickers, burbles, sweeps, and whistles of a sort usually obtainable only via synthesizers or software sequencers. And even veteran techno-tweakers will make exciting discoveries within seconds of plugging in.

Basic Beats
The AdrenaLinn's drum machine is a no-frills affair: a simple four-voice beatbox with a 32-step sequencer and generic sounds. While you can conjure trippy effects by routing these sounds through the effects section, the drum box is probably best viewed as the rhythmic graph paper over which you sketch sounds. You can use the beats as backing while concocting rhythmic effects, and then mute them during performance.

Thanks to the pedal's MIDI In and Out jacks, you can sync to an external sequencer, or clock a sequencer to the AdrenaLinn. You can also route the drum sounds and guitar effects to separate outputs-perfect for recording drum-free guitars while using the rhythm patterns as click tracks. Finally, you can simply plug in and jam, entering your tempo via footswitch. (In lieu of a tap-tempo switch, the AdrenaLinn has a Hold Tempo function in which you set the speed by depressing the switch for an entire measure, as opposed to tapping in quarter-notes.)

Sounds
It's difficult to summarize the AdrenaLinn's tones because its flexible modulation routing offers such an extraordinary array of options. You get warm delays, rich tremolo, and fat, tactile flanging-all synchable to tempo at rates ranging from once every eight bars to thirty-second-note triplets. All can be controlled by your playing dynamics, external MIDI control, or any of five LFO waveforms, including a random option. There are many fresh flavors here, such as envelope-driven flanging and random tremolo. But the biggest thrills reside in the filter section. Here you can select between two low-pass-filter types: a warm Oberheim-style two-pole model, and an edgier Moog-style four-pole-both with adjustable cutoff frequency, resonance, and attack and decay times.

It's no surprise that the AdrenaLinn excels at the two traditional auto-wah sounds: shimmering, LFO-driven sweeps and funky/quacky envelope filtering. But the pedal goes beyond such stompbox-filter stalwarts as the Moogerfooger and Mu-Tron III in offering a programmable 32-step filter sequencer, with each step's cutoff adjustable on a scale of 0 to 99. You can create countless rhythm grooves, seizure-grade oscillations, and, at high-resonance settings, even sequenced melodies.

Sound cool? It certainly does. But there's more. The sequencer and other modulation sources can also control volume/tremolo, panning, and flanging effects. When you combine the complex filtering with ricochet delay and panning effects-well, it gets pretty deep. With these programs, a single strummed chord can generate a winning song idea.

The AdrenaLinn also offers a set of 12 amp models in the usual Fender, Marshall, Vox, and boutique flavors. The simulations are reasonably good, but there's little editing depth, and not even a choice of speaker type. While you can definitely get keeper tones by plugging straight into a mixer, many users may opt to bypass the AdrenaLinn's modeling in favor of analog amps or other modeling units. Like its drum machine, the AdrenaLinn's amp simulations are probably best viewed as nice side dishes rather than the main course. (One clever feature: you can place the effects before or after the modeling. Post-model flanging, for example, has a deliciously tape-like texture.)

Ease of Use
There are two basic approaches to working with the AdrenaLinn: The easy way and the hard way. If you plan to build programs from scratch, expect to spend a lot of time toggling between parameters and squinting at tiny text. Aside from the small lights lining the edit grid, your sole visual feedback is a three-character LED prone to bewildering abbreviations. Entering drum patterns and filter sequences is even more labor-intensive. You must toggle to the target step, and then dial in a numeric value. It's logical. It's workable. But it's not fun. (If you have Emagic's Sound Diver editing software, you can access all AdrenaLinn parameters via a single computer screen.)

The easier method is to simply sift through the presets. This is an especially attractive way to work if you're synching to recorded tracks. I slaved the AdrenaLinn to a Pro Tools rig-a piece of cake-opened a song in progress, and simply spun the dials while noodling. I was rewarded with so many cool possibilities, I couldn't record them fast enough.

Reaction Time
Cool as the AdrenaLinn is, a few extra features would have made it even cooler. A headphone jack is an odd omission, and there's no way to switch programs without using your hands or a MIDI controller pedal. The ability to recall a few favorite programs by footswitch à la the Line 6 modeler pedals would make the AdrenaLinn vastly more suitable for onstage use. (You can use the bypass switch to toggle between any two programs, but if both programs include effects, you sacrifice footswitch bypass.) A dry/effect mix control would have been welcome, as well.

Yet the AdrenaLinn would have nabbed our Editors' Pick Award even if it included no drum sounds or amp modeling. It's innovative, powerful, and reasonably priced-not to mention wicked, wicked fun. Only the unluckiest of guitarists will fail to wring compelling new sounds from this super-hip gizmo.