Introduction
This manual provides essential information for the safe and effective use of your VOX VT20X Modeling Guitar Combo Amplifier. Please read this manual thoroughly before operating the unit to ensure proper setup, operation, and maintenance. Retain this manual for future reference.

Image: Front view of the VOX VT20X Modeling Guitar Combo Amplifier, showcasing its black textured finish and classic diamond-patterned grille cloth with the VOX logo.
Important Safety Precautions
- Power Supply: Use only the specified power adapter. Ensure the voltage matches the requirements of your region.
- Ventilation: Do not block ventilation openings. Ensure adequate airflow around the amplifier to prevent overheating.
- Moisture: Do not expose the unit to rain, moisture, or excessive humidity. Keep liquids away from the amplifier.
- Placement: Place the amplifier on a stable, level surface. Avoid placing it near heat sources or in direct sunlight.
- Servicing: Do not attempt to service the unit yourself. Refer all servicing to qualified service personnel.
- Headphone Use: Prolonged listening at high volume levels can cause hearing damage.
Setup
Unpacking and Initial Inspection
Carefully remove the amplifier from its packaging. Inspect the unit for any signs of damage during transit. Ensure all included accessories are present:
- VOX VT20X Amplifier
- Power Adapter
- User Manual (this document)
Connecting Your Amplifier
- Power Connection: Connect the supplied power adapter to the DC IN jack on the rear panel of the amplifier, then plug the adapter into a suitable AC outlet.
- Guitar Connection: Connect your guitar to the INPUT jack on the top panel using a standard 1/4-inch instrument cable.
- Optional Footswitch: If using an optional VOX VFS2 or VFS5 footswitch, connect it to the FOOT SW jack.
- Auxiliary Input: For connecting external audio devices (e.g., MP3 player, smartphone), use the AUX IN jack.
- Headphones: For silent practice, connect headphones to the HEADPHONE jack. This will mute the internal speaker.

Image: Detailed diagram of the VOX VT20X amplifier's top control panel, labeling various inputs, knobs, and buttons such as Input Jack, Preset Toggle, Amp Model Selector, Gain, 3-band EQ (Treble, Middle, Bass), Volume, Power Scaling Knob, Aux In Jack, Tube Bias Shift Toggle, Real 12AX7 Tube Preamp, External Footswitch Jack, User Program Bank, Effects Section, Effects Parameter Controls, Tap Tempo for Effects, Headphone Output, and Class A/AB Switch.
Operating the VT20X Amplifier
Powering On/Off
Ensure all connections are secure. Turn the VOLUME knob to its minimum setting before powering on. Press the POWER button to turn the amplifier on. To turn off, press the POWER button again.
Understanding the Controls
- INPUT Jack: Connect your guitar here.
- PRESET Toggle: Switches between preset modes and manual mode.
- AMP MODELS: Selects from 20 different amplifier models. Rotate the knob to choose your desired amp type.
- GAIN: Adjusts the amount of distortion or overdrive.
- 3-Band EQ (TREBLE, MIDDLE, BASS): Shapes the tonal characteristics of your sound.
- VOLUME: Controls the overall output volume.
- POWER LEVEL: Adjusts the output wattage, allowing for tube-like response at lower volumes.
- AUX IN Jack: Input for external audio devices.
- TUBE BIAS SHIFT Toggle: Adjusts the bias of the 12AX7 vacuum tube for different tonal characteristics (Green: Cold, Red: Hot).
- CLASS A/AB Switch: Selects between Class A and Class AB power amp operation, influencing the amplifier's response and feel.
- USER PROGRAMS (CH1-CH4, BANK): Allows you to save and recall your custom settings. Use the BANK button to cycle through banks (A, B, C, D) and CH buttons to select channels within each bank. To save a setting, press and hold the desired CH button until it flashes.
- EFFECTS Section (PEDAL1, PEDAL2, REVERB):
- PEDAL1: Compression, Chorus, Overdrive, Distortion.
- PEDAL2: Flanger, Phaser, Tremolo, Delay.
- REVERB: Room, Spring, Hall, Plate.
- TAP Button: Used to set the tempo for time-based effects like Delay and Tremolo.
- USB Port: Connects to a computer for use with the Tone Room editor/librarian software.
- FOOT SW Jack: For connecting an optional footswitch (VFS2/VFS5) for hands-free control of programs and effects.
Using the Tone Room Software
The VOX VT20X can be connected to a computer (PC/Mac) or mobile device (iOS/Android) via the USB port. The Tone Room software allows for deeper editing of amp models and effects, as well as managing user programs. Download the latest version of Tone Room from the official VOX website.

Image: A VOX VT20X amplifier with a smartphone connected via USB, displaying the Tone Room application interface for editing amplifier settings and effects.
Maintenance
Cleaning
To clean the amplifier, use a soft, dry cloth. Do not use abrasive cleaners, waxes, or solvents, as these can damage the finish. Ensure the unit is unplugged before cleaning.
Storage
When not in use for extended periods, store the amplifier in a cool, dry place away from direct sunlight and extreme temperatures. Protect it from dust and moisture.
Tube Replacement
The VT20X features a 12AX7 vacuum tube in its preamp section. While designed for longevity, tubes may eventually require replacement. If you notice a significant degradation in sound quality or unusual noise, consult a qualified technician for tube inspection and replacement. Only use genuine VOX replacement tubes or equivalent specifications.
Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| No Sound |
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| Distorted/Unwanted Noise |
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| Controls Not Responding |
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If the problem persists after attempting these solutions, please contact VOX customer support or a qualified service center.
Specifications
| Feature | Detail |
|---|---|
| Model Name | VT20X |
| Output Wattage | 20 Watts |
| Speaker | 1 x 8-inch VOX original |
| Amp Models | 20 (using VET technology) |
| Effects | 12 (8 Pedal effects, 4 Reverb effects) |
| User Programs | 8 (2 banks x 4 channels) |
| Tube | 12AX7 (Valvetronix tube preamp) |
| Inputs | INPUT, AUX IN, FOOT SW |
| Outputs | HEADPHONE |
| Connectivity | USB (Type B) |
| Dimensions (W x D x H) | 9.8 x 19.7 x 16.9 inches (approx.) |
| Weight | 16.09 lbs (approx.) |
| Power Source | Corded Electric |

Image: A visual summary of the VOX VT20X amplifier's key specifications, including 20 amp models, 21 effects, tube powered preamp circuit, 20 Watts output, 1 x 8" speaker, and headphone out/AUX in.

Image: A diagram illustrating the physical dimensions (height, width, depth) and weight of the VOX VT20X amplifier. Dimensions are shown as 13.66" H, 16.14" W, 8.86" D, and weight as 16.09 lbs.
Warranty and Support
Warranty Information
For detailed warranty information, please refer to the warranty card included with your product or visit the official VOX website. Keep your proof of purchase for warranty claims.
Customer Support
If you require technical assistance, have questions about your product, or need to arrange for service, please contact VOX customer support. Contact information can typically be found on the official VOX website or in the product packaging.
You can also visit the VOX Store on Amazon for additional product information and resources.





