Review: DigiTech GSP1101

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The GSP1101 guitar preamp/processor aims to deliver the high level of transparency and quality that working guitarists demand, while maintaining a reasonable price point compared with other high-end processors. It provides all the modeling you''d expect in a complete guitar processor, including simulated amplifiers, cabinets, stompboxes, and other effects. The single-rackspace unit features myriad I/O options, allowing you to use it either as a complete guitar tone generator or as part of an existing amplifier and effects system. For studio use, DigiTech furnishes a cross-platform software editor. For stage use, you can purchase the optional Control 2 remote foot controller ($299).

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FIG. 1: The GSP1101 is the flagship processor in DigiTech''s Pro Guitar line, offering amplifier, cabinet, stompbox, and effects models in a rackmount module.

I/O for All Seasons

On the GSP1101''s front panel, alongside the high-impedance ¼-inch input and ¼-inch stereo headphone jack, the Output Level knob controls the headphone and line output levels (see Fig. 1). It can control the unit''s mixer output levels as well. Near the panel''s center are a graphical LCD, an LED that shows the preset number, and the large Edit/Select knob. Three buttons instantly access the Tone Library, the Effects Library, and the Effects Level parameter. Five knobs are dedicated to adjusting standard guitar preamp controls. Additional buttons step backward through menus, store changes to presets, bypass effects, and activate a built-in tuner.

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FIG. 2: X-Edit 2.2 is an editor-librarian for the GSP1101 that gives easy access to all of a preset''s parameters and presets.

You navigate through presets and parameters using the Edit/Select knob. To access individual parameters, you navigate to the desired effect or submenu, push on the knob, and then dial in the desired parameter value. The Tone Library button provides quick access to 40 distortion and amp tones, and the Effects Library button accesses 40 user-programmable effects settings. If you want to do some deep editing, you may prefer to use the cross-platform X‑Edit editor-librarian on a computer display rather than the GSP1101''s LCD (see Fig. 2; for details, see the online bonus material at

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FIG. 3: The GSP1101''s rear panel furnishes enough I/O options to integrate it into nearly any live or studio guitar rig.

The rear panel has a pair of balanced ¼‑inch outputs to an amplifier or line-level device, and a pair of balanced XLR mixer outputs with a ground-lift switch (see Fig. 3). There are also three ¼-inch jacks—a mono send and two returns—for an external loop. You can configure the loop as a preamp or effects loop. MIDI In and Thru jacks let you connect the unit to MIDI controllers, and a USB jack allows for 2-way communication with your computer. Also on the rear are ¼-inch jacks for a footswitch and an expression pedal and a Cat-5 port for the optional Control 2.

Guitar Wizard

The GSP1101''s wealth of I/O options allows connection to nearly any equipment that a guitarist might own, from USB-based desktop guitar rigs to various stage setups. You can connect the unit direct to a mixing console or plug it straight into your guitar amp''s effects loop. The most complete method for connecting the GSP1101 to a guitar preamp or amplifier with an effects loop is to use a configuration known as the 4-cable method (see the online bonus material).

To prevent guitarists from being overwhelmed by so many configuration options, the GSP1101 comes with a convenient Setup wizard, which you invoke by holding down the Tuner button. The Setup wizard walks you through a series of screens reflecting how you have the GSP1101 integrated into your rig (asking if you''d like to use the preset amp and cabinet models and so on) and sets all the parameters for you. It works extremely well; the Setup wizard accurately configures half a dozen parameters in response to just a couple of selections you make.

Playing with Blocks

The GSP1101 contains ten effects blocks: wah, compressor, distortion, noise gate, amp model, cabinet model, parametric EQ, chorus/FX, delay, and reverb. The external loop is positioned between the amp model and cabinet model. Each block can be independently turned on or off. Although the order of effects blocks cannot be changed, the chorus/FX block can be placed predistortion instead of post-EQ.

The amp block offers 36 models of amps from manufacturers such as Fender, Marshall, Vox, Mesa/Boogie, Carvin, Matchless, Soldano, and Hiwatt, as well as original DigiTech models (including 2 acoustic models). Twenty-three cabinet models are split between emulations of classic cabinets and custom DigiTech models.

Each effects block contains emulations of stompboxes and digital effects. The wah, compressor, and distortion blocks model popular stompboxes and footpedals such as Dunlop and Vox wahs, Boss and MXR compressors, and 17 popular and boutique fuzz boxes. The digital effects are also models of classic pedals and effects—some from DigiTech and some from Boss, MXR, Electro-Harmonix, and others. You get chorus, flanger, phaser, pitch effects, vibrato/rotary effects, tremolo, envelope effects, and delays. The reverb algorithms were mostly borrowed from Lexicon (another Harman company), with one Fender Twin spring and one EMT plate emulation. The GSP1101 offers a global EQ applied to its output.

I wish the effects blocks could be rearranged. I''d also like to be able to use multiple instances of the same block (many different delays in series, for example). However, I assume that fulfilling my requests would require more DSP horsepower than the GSP1101 has.

Delicate Sound of Thunder

The sound quality of the amp and the effects that respond to playing dynamics are top-notch. The Fender and Marshall amps sound very realistic; the Mesa/Boogie and Soldano emulations sound heavy and scooped without sounding overly nasal. The wah and compressors all sound quite natural, and the tube screamer, classic models, and Demeter Fuzzulator models are excellent. Most models also cleaned up well when I lowered the setting on my guitar''s volume knob. However, some of DigiTech''s own hybrid fuzz and heavy amp models are a bit too screechy and over the top for my taste.

The simulations of the smaller (1 5 12 and 2 5 12) cabinets sound open and realistic, but to my ear, the larger cabinets sometimes sound as though they''re slightly comb filtered. Still, it was easy to select a cabinet simulation that I liked and make it the global cabinet for all presets.

The effects algorithms are uniformly excellent. The choruses are clean and shimmery. The flangers and phasers are appropriately modern or vintage. Delays sound good, especially the modulation delay. And the Lexicon reverbs are really nice, with fewer parameters than a Lexicon hardware unit offers, but with the same glorious sound. My only disappointment was the Vox tremolo: I have clocked many hours on Vox amps, and this emulation, though good, is not quite as rich as the real thing.

I played the GSP1101 directly into my Mac via USB. I also played it into the front end of my Egnater MOD50 tube amp using the Clean setting. In addition, I set it up using the 4-cable method to emulate effects both in front and in the loop of my amp. In each configuration, the GSP1101 was transparent; it didn''t produce any noise or compromise the amp''s natural tone. When used with a hardware amp, the GSP1101 lets you globally turn off its amp and cabinet simulations.

This One Goes to . . .

The DigiTech GSP1101 packs a heck of a lot into a single rackspace. It comes with a comprehensive software editor-librarian and drivers for USB recording. I do wish the driver had the facility to reamp over USB as well as record and play back audio on your own computer, but DigiTech said this was not technically feasible because of USB timing issues.

The GSP1101 also includes comprehensive MIDI preset mapping and continuous controller support, allowing every parameter to be controlled remotely using MIDI Control Change messages on any MIDI channel you specify. With its extensive flexibility and functionality, the DigiTech GSP1101 is an amazing value and can easily compete with guitar processors that sell for twice its price.

When Orren Merton isn''t writing and editing music-technology books for Course Technology PTR, he simulates being a guitarist for Ember After (