When I first heard about DigiTech's GNX4 Guitar Workstation a modeling and multi-effects processor that's also a pedalboard, a standalone 8-track digital
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When I first heard about DigiTech's GNX4 Guitar Workstation — a modeling and multi-effects processor that's also a pedalboard, a standalone 8-track digital recorder, a USB audio and MIDI interface (with included DAW and editor-librarian software for Mac and Windows), a looper, a drum machine, a mic preamp-DI, a card reader, and more — I was skeptical. I wondered if its feature set was overly ambitious.

But after working with it for several weeks, my skepticism has vanished. The GNX4 does what it promises, and does it well. It's an intelligently designed unit that will benefit any recording guitarist, especially one who is new to digital multitracking.

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FIG. 1: In addition to its modeling and multi-effects functions, the DigiTech GNX4 is an 8-track recorder, a USB MIDI and audio interface, a mic preamp, a looping device, and much more.

But the GNX4 is more than just a recording product — it's a formidable live-performance tool. It provides gigging guitarists with a wide range of sounds and effects and, because of its speaker-modeling capabilities, you have the option of plugging straight into the P.A.

The unit's onboard CompactFlash-based 8-track recorder and MP3 player would be a godsend for solo acts that use backing tracks. They could record or import their material into the GNX4 and control playback using the unit's footswitches. Because EM focuses on the personal studio, however, this review will emphasize the GNX4's recording functions.

Pedals to the Metal

At just under 22 inches in width, the metal-housed GNX4 is wider than a typical pedalboard-style processor (see Fig. 1). It's outfitted with seven large footswitches (a row of five and a row of two), an expression pedal, and an assortment of hand-controlled switches and knobs.

Most of the rear panel (see Fig. 2) is dedicated to I/O. You get a high-impedance instrument input, an XLR input for the built-in dbx mic pre (which has a -20 dB pad and switchable 48V phantom power), a pair of ¼-inch balanced line inputs, two ¼-inch balanced line outputs with an output adjustment knob and a speaker compensation (simulation) switch, two balanced XLR line outputs (with an output adjustment knob, a speaker compensation switch, and a ground lift switch), a footswitch input for an optional recording-control unit, a ¼-inch headphone output, MIDI In and Out jacks, and a USB port.

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FIG. 2: The GNX4''s rear panel is where connections are made for its various types of I/O, which include analog and digital audio, and MIDI.

DigiTech clearly made an effort to keep the user interface (especially for the guitar-sound engine) as straightforward as possible, considering the unit's ample feature set. The GNX4's GeNetX Amp Controls Matrix — a gridlike combination of buttons, knobs, switches, and parameter names on the unit's front panel — is used for programming effects and amp models. Along with the two main LED displays, it allows you to thoroughly and quickly edit guitar-sound parameters without having to dig deep into menus.

The trade-off for this easy-to-use interface is that the size of the parameter names printed on the front panel had to be shrunk in order to fit. They were so small that even when I sat down with the GNX4 on the floor below me, I found them difficult to read. It was virtually impossible to read them when standing above the unit. As a result, I had to do most of my serious guitar-sound tweaking (when I wasn't using the included XEdit software) with the unit on my lap or on a table — neither of which is conducive to programming a unit that's primarily foot operated.

When you aren't programming sounds, the four LED displays on the unit's front panel show you everything you need, and they can easily be read from a distance or even on a dark stage. The largest of the displays gives you the patch names and shows the status of various functions and settings, depending on which one you're adjusting.

Just to the right of it is a small 2-digit LED that reads out patch numbers, the recording destination (the USB output or the onboard recorder), and many other status indicators. On the extreme left of the unit are two LEDs for the digital recorder; one reads out song number, and the other reads out elapsed time. Many of the GNX4's knobs and switches have LED status lights.

Sounding Out

The heart of the GNX4 is its impressive guitar processing. It uses DigiTech's GenetX technology, which the company used in previous GNX and Genesis products. It allows you to take two amp models and Warp (morph) them to any degree you like. Once accomplished, you can store your new hybrid-amp model (called a HyperModel) to one of nine memory locations. You can then Warp it with one of the other models to create yet another HyperModel. The possibilities are endless.

All that Warping would be pointless if the models didn't sound good, but they definitely do. The GNX4 has 15 guitar-amp models, emulating amps by, among others, Fender, Marshall, Mesa/Boogie, Vox, and Matchless. You also get a decent acoustic-guitar simulator, and ten bass-amp models that mimic amps from such brands as Hartke, Acoustic, Trace Elliot, Ashdown, Sunn, and Fender. For further tone shaping, you can choose from 22 speaker-cabinet models, covering a wide range of guitar and bass enclosures.

I was impressed by the sounds overall, especially when I started doing my own programming. I was even able to get some convincing clean sounds, which is often difficult with modeling devices.

There are 80 user and 80 factory preset memories available, and you can save 80 more if you've installed a Type 1 CompactFlash card (which is not included) into the GNX4's card slot. Each preset contains two amp channels, which can be assigned to different models. You can switch between them or set the expression pedal to control the Warping process.

You can set the GNX4 to three modes, each of which allows footswitch control of different functions. Preset mode lets you use the footswitches to choose between various presets. Stompbox mode lets you turn effects on and off within a preset and switch between amp models. Recorder mode allows you to control the onboard recorder or the Cakewalk Pro Tracks Plus 2.2 DAW software.

Wahs and Yahs

Each preset can include one of the GNX4's Stompbox models, which re-create various well-known distortion pedals. You get Rodent (ProCo Rat), Screamer (Ibanez Tube Screamer), and Big MP (Electro-Harmonix Big Muff Pi), among others.

The GNX4 also offers a generous variety of good digital effects. Each preset can have one of several delays, a choice of reverb algorithms, a noise gate, compression, and a chorus or a modulation effect (such as flanger, phaser, wah, auto-wah, Ya Ya [a superb talkboxlike effect], tremolo, auto pan, rotary speaker, detune, and fixed pitch shift).

Each preset can also have an effect from the Whammy-IPS-Talk category, which includes various specialized pitch effects. Whammy is taken from DigiTech's own Whammy pedal, and it lets you bend your note by a specified interval (or add a harmonized bend) using the expression pedal. You can do everything from dive-bombing effects to more subtle bends.

In addition to controlling Whammy, the expression pedal can be programmed to work with a huge range of parameters. A wah is available at any time by pressing the toeswitch of the expression pedal. The sensitivity of the switch can be adjusted, but the default setting on my review unit was just right. The pedal action, however, was a bit stiff.

IPS stands for Intelligent Pitch Shifter. Unlike the fixed shift effect found in the unit's Chorus/Mod section, this one is based on a user-specified interval, scale type, and key. As a result, you can play some very musical guitar harmonies with yourself (see Web Clip 1).

The Talker is a talkbox effect that works in conjunction with the built-in mic input. You plug in a mic and talk while playing, and it imparts vocal qualities to your guitar sound. It was a disappointment; I wasn't able to get very discernable effects from it. For talkboxlike sounds, I much preferred the Ya Ya and Auto Ya effects.

Bang on the Drum Machine

Another useful feature of the GNX4 is its drum machine, whose patterns and sounds can be used with the onboard multitrack. It can be also function as a MIDI drum module or simply as a practice aid.

You get 110 patterns, covering styles such as funk, jazz, rock, metal, and country. The patterns are basic but are fine for songwriting and practicing purposes. You can't, however, chain patterns together into a song, which is somewhat limiting. You get eight kits, each with sounds representing a particular musical style. The drum sounds are average, at best.

If you've installed a CompactFlash card, you can use the unit's card-reader function (which makes the card appear to your computer as an external drive) to import MIDI drum files into the GNX4. You can then play the MIDI files using the unit's internal sounds. Therefore, you aren't limited to the onboard patterns, and you can even dump song-length MIDI drum tracks into the drum machine.

You can also use the card-reader function to import MP3s into the GNX4. One excellent use of this feature would be to import backing tracks into the unit to perform or practice with.

Let's Record

The GNX4 offers two choices for recording: the built-in, 8-track multitrack, and the unit's USB audio interface for recording into a computer.

Before getting into the specifics, I should mention that the unit has three different audio-input options. You can plug your guitar in directly through the instrument input, plug a mic into the built-in mic preamp, or patch line-level signals into the balanced line inputs.

Because DigiTech is under the same corporate umbrella (Harman Music) as dbx, it was able to include a dbx mic preamp in the GNX4. I tested the preamp out on acoustic guitar (see Web Clip 2) and on vocals, and it sounded good but a tad darker than the other pres in my studio.

Multitrack Onboard

The GNX4's 16-bit, 44.1 kHz onboard digital recorder isn't as fully featured as a dedicated multitrack or DAW, but it is useful and portable. You must install a CompactFlash card for it to function. Your total recording time will vary greatly depending on what type of card you get. For example, a 32 MB card will yield a total of 6 minutes. A 2 GB card (the maximum compatible size) gives you 6 hours and 24 minutes. (To calculate the available recording time per track, divide the total time by the number of tracks that you plan to record.)

The GNX4 lets you set a number of recording preferences, including whether to have a count off and whether to play with the click track or the drum machine on. You can set the drum machine to play along or to record to two of the tracks. Once you have configured everything, recording is a snap. You don't even need to use your hands, because the recorder's transport can be controlled with the unit's footswitches.

When it's time to mix, you can control level and pan for each track. You can either output your mix to an external 2-track through the analog outputs or use the card-reader function to transfer the individual tracks to a DAW for subsequent mixdown. If you want to keep your mix onboard, you can bounce it to two of the tracks (see Web Clip 3) — and you don't need to leave open tracks to do so.

Does It Compute?

The other recording option is to use the included DAW software — Pro Tracks Plus 2.2 for the PC or BIAS Deck SE 3.5 for the Mac (or other compatible DAW software) — and use the GNX4 as a USB interface. Pro Tracks Plus has more-thorough integration with the GNX4 than Deck SE does. You can even control Pro Track Plus's transport with the GNX4's footswitches (see Web Clip 4).

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FIG. 3: One of the programs included with the GNX4 is Cakewalk''s Pro Tracks Plus (Win), a fully featured digital audio sequencer.

Pro Tracks Plus (see Fig. 3) is a very capable sequencer that can handle audio and MIDI recording, editing, and mixing. Cakewalk adapted the software from its Sonar line. Having such a fully featured application included is a real plus. In addition, you get the Lexicon Pantheon reverb plug-in (another benefit of the Harman connection), which also comes in a Mac version for Deck SE.

I successfully tested the GNX4's USB drivers with Cakewalk's Sonar 4 and Project 5. I was not able to get the audio to work correctly with Sony's Acid Pro 5.

On the Mac side, Deck SE 3.5 is a capable recording program but is more limited than Pro Tracks Plus because it doesn't offer any MIDI-sequencing features. I also tested the GNX4's USB interface successfully with several other Mac programs including MOTU Digital Performer 4.52, Apple GarageBand 2.01, and Logic Pro 7.1.

The GNX4 offers a wide range of options for outputting audio to the computer. You can choose between stereo, mono, with effects, without effects, and several other options. It also has settings that facilitate reamping tracks from the computer using the unit's models and effects. In all, the GNX4 handled its role as an audio and MIDI interface quite well.

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FIG. 4: The included XEdit software (Mac/Win) makes the job of editing and storing the GNX4''s guitar sounds a snap.

XEdit (see Fig. 4), the editor-librarian program (Mac/Win) that comes with the GNX4 software package, gives you a graphic representation of all the guitar and effect parameters in the hardware unit. Editing with it is a breeze, and you can save and recall your favorite patches.

PC users get Cakewalk Pyro Express in the GNX4 software package, which is a light version of Cakewalk's Pyro, and lets you burn and rip CDs.

Loop and Jam

The GNX4's digital recorder also serves as a looping device. The feature is called JamMan and is loosely based on the Lexicon JamMan — a classic looping device that's no longer in production. The GNX4's looper lets you overdub multiple passes (limited only by the size of the CompactFlash card) over a looping section.

Unlike the original JamMan, the DigiTech unit lets you do multitrack looping. The GNX4's versatile footswitches allow hands-free control of all looping functions.


Because of its many and varied functions, the GNX4 is relatively difficult to learn. Although DigiTech attempted to keep things as simple as possible, the GNX4 has so many features that it takes a while to get comfortable with the unit's operations. Even after several weeks of testing, I still had to refer to the manual fairly often — especially for the recorder, digital-output, and data-transfer functions, which have more menus and hidden features than the relatively straightforward guitar-processing section.

Fortunately, the manual is informative and comprehensive. My only complaint with it is that it has no index, although it does have a detailed table of contents.

Genetically Engineered Music

Overall, the GNX4 is an ambitious unit that succeeds at what it sets out to do. Its guitar-sound engine is flexible and deep. Combine that with the onboard recorder, the drum machine, and the dbx mic pre, and you have a self-contained, songwriting and demo studio that can be used anywhere that has electricity. The ability to transfer tracks to the computer for further polishing is also handy.

The GNX4's capabilities as a MIDI and audio interface (albeit somewhat limited in terms of I/O) and its facility to store and transfer data from a CompactFlash card allow it to work as a functional front end for Mac and PC setups. The included software is quite good (especially on the PC side) and adds a lot of value to the total package.

Although the GNX4 is aimed most directly at guitarists who've previously been reluctant to jump into the computer-recording world, its versatility will make it attractive to many recording and performing guitarists.

Mike Levine is an EM senior editor.


Audio Inputs (1) ¼" TS unbalanced instrument, (2) ¼" TRS balanced line, (1) XLR balanced mic Audio Outputs (2) ¼" TRS balanced line, (2) XLR balanced line, (1) ¼" TRS headphone Digital I/O USB Type B MIDI In/Out Phantom Power 48V Presets 80 factory, 80 user, 80 card (with optional CompactFlash card installed) A/D/A Converters 24-bit Sampling Frequency 44.1 kHz CompactFlash Card Interface Type 1 (solid-state cards; up to 2 GB) Onboard Digital Recorder 8-track, 16-bit, 44.1 kHz resolution MP3 Player 32-320 kbps supported Onboard Drum Machine 110 patterns, 5 metronome settings, 8 drum kits Dimensions 21.5" (W) × 3.25" (H) × 9" (D) Weight 10 lbs.


guitar workstation
$ 699.95


PROS: Excellent sounds and effects. Warp feature adds additional flexibility. Onboard multi track looper, drum machine, and MP3 player. Card reader makes exchange of data to computer easy. Functions well as USB audio and MIDI interface. Dbx mic pre. Recording and editing software (Mac/Win) included.

CONS: Drum-machine patterns can't be chained together. Drum patterns and sounds are mediocre. Parameter information printed on the unit can be hard to read. Recorder and interface functions difficult to learn. Talker effect unimpressive.