1. Product Overview
The Behringer V-Tone Guitar GDI21 is an analog guitar modeling preamp/stompbox with a direct recording DI output. This versatile unit allows guitarists to achieve a wide range of amplifier sounds in a compact pedal format, suitable for both live performance and studio recording.
Key features include:
- Analog guitar modeling preamp/stompbox with DI recording output.
- Provides a variety of amplifier sounds with simple switch selection.
- Precise level and drive control, plus a musical 2-band EQ for sound shaping.
- Output options include 1/4" TS or balanced, gold-plated XLR connectors.
- Operates on a 9V battery or an optional BEHRINGER PSU-SB DC power supply.
Figure 1: The Behringer V-Tone Guitar GDI21, a blue guitar amp modeler and direct recording preamp/DI box. It features four black control knobs for Drive, Treble, Bass, and Level, along with several toggle switches for Amp modeling (Tweed, Brit, Calif), Mod (Hot, HiCut, Cln), and Mic position (Off Ax, Cntr, Clsc). A large footswitch is visible at the bottom right.
2. Setup and Connections
2.1 Power Supply
The GDI21 can be powered by a 9V battery or an optional BEHRINGER PSU-SB DC power supply (not included). To install a battery, open the battery compartment located on the bottom of the unit.
2.2 Connecting Your Guitar
Connect your guitar to the INPUT jack on the GDI21 using a standard 1/4" TS instrument cable.
2.3 Output Connections
The GDI21 offers two output options:
- 1/4" TS Output: Connect this to the input of your guitar amplifier or other instrument-level device.
- XLR DI Output: For direct recording or connecting to a mixing console, use a balanced XLR cable. This output provides a low-impedance signal suitable for long cable runs and direct input into professional audio equipment.
2.4 Ground Lift Switch
The GND LIFT switch helps eliminate hum caused by ground loops when using the XLR output. If you experience hum, try toggling this switch.
3. Operation and Controls
The GDI21 features intuitive controls to shape your guitar tone. Experiment with different settings to find your desired sound.
3.1 Control Knobs
- DRIVE: Adjusts the amount of gain and distortion. Higher settings produce more saturated and overdriven tones.
- TREBLE: Controls the high-frequency content of your sound. Turn clockwise for brighter tones, counter-clockwise for warmer tones.
- BASS: Controls the low-frequency content of your sound. Turn clockwise for more bass, counter-clockwise for less.
- LEVEL: Sets the overall output volume of the unit.
3.2 Amp Modeling Switch (AMP)
This 3-position switch selects between different amplifier models:
- TWEED: Emulates the sound of a classic 1950s Fender Bassman amplifier, known for its warm, clean, and slightly overdriven tones.
- BRIT: Simulates the sound of a British Marshall JCM800 amplifier, famous for its aggressive, high-gain rock tones.
- CALIF: Models the sound of a modern Mesa Boogie Rectifier amplifier, characterized by its powerful, scooped-mid, high-gain metal tones.
3.3 Mode Switch (MOD)
This 3-position switch adjusts the gain structure and character of the selected amp model:
- HOT: Provides a higher gain setting, ideal for lead tones and heavier distortion.
- HICUT: Offers a more scooped mid-range and rolled-off high end, suitable for rhythm guitar or a smoother lead tone.
- CLN: Delivers a cleaner, less distorted sound, useful for pristine cleans or as a base for other effects.
3.4 Microphone Placement Switch (MIC)
This 3-position switch simulates different microphone placements on a speaker cabinet, affecting the tonal response:
- OFF AX: Simulates an off-axis microphone placement, resulting in a slightly darker tone with less direct high-end presence.
- CNTR: Simulates a microphone placed directly in the center of the speaker cone, providing a brighter, more direct, and punchy sound.
- CLSC: Offers a classic microphone placement sound, often characterized by a balanced tone with good clarity and warmth.
3.5 Footswitch
The large footswitch engages or bypasses the GDI21's effects. When engaged, the LED indicator will illuminate.
4. Maintenance
4.1 Cleaning
To clean the unit, use a soft, dry cloth. Do not use any abrasive cleaners or solvents, as they may damage the finish or internal components.
4.2 Battery Replacement
If using battery power, replace the 9V battery when the LED indicator dims or the sound quality degrades. Ensure proper polarity when inserting the new battery.
4.3 Storage
Store the GDI21 in a cool, dry place away from direct sunlight and extreme temperatures. If storing for an extended period, remove the battery to prevent leakage.
5. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| No sound or weak sound |
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| Excessive hum or noise |
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| LED not illuminating |
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6. Technical Specifications
| Feature | Detail |
|---|---|
| Model | GDI21 |
| Type | Guitar Amp Modeler / Direct Recording Preamp/DI Box |
| Power Source | 9V Battery or BEHRINGER PSU-SB DC Power Supply (not included) |
| Inputs | 1/4" TS Instrument Input |
| Outputs | 1/4" TS Output, Balanced XLR DI Output |
| Controls | DRIVE, TREBLE, BASS, LEVEL knobs; AMP, MOD, MIC, GND LIFT switches; Footswitch |
| Dimensions (H x W x D) | 1.97 x 3.94 x 5 inches (approx.) |
| Weight | 1.1 pounds (approx.) |
| Material | Metal |
| Color | Blue |
| Date First Available | October 2, 2001 |
7. Warranty and Support
7.1 Product Support
For technical assistance, product registration, or to download the latest drivers and software, please visit the official Behringer website or contact their customer support.
You can find more information and support resources by visiting the Behringer Store on Amazon.
7.2 Warranty Information
Behringer products typically come with a limited warranty. Please refer to the warranty card included with your product or visit the official Behringer website for detailed warranty terms and conditions specific to your region. Protection plans may also be available for extended coverage.
