1. Introduction
Thank you for choosing the Ampeg Rocket Bass RB108 Bass Combo Amplifier. This manual provides essential information for the safe and efficient operation of your new amplifier. The RB108 is a 30-watt, 1x8" combo amplifier designed for bass players seeking classic Ampeg tone in a portable package. It features a 3-band EQ, Super Grit Technology (SGT) overdrive, and convenient auxiliary and headphone inputs for practice.
Figure 1: Front view of the Ampeg Rocket Bass RB108 Bass Combo Amplifier, showcasing its classic design with a black checkered Tolex finish and silver grille cloth.
2. Safety Information
Please read and understand all safety instructions before operating this product. Retain this manual for future reference.
- Power Source: Connect the amplifier only to the specified power supply voltage. Ensure the power cord is not damaged.
- Ventilation: Do not block ventilation openings. Ensure adequate airflow around the amplifier to prevent overheating.
- Moisture: Do not expose the amplifier to rain or moisture. Avoid placing liquids on or near the unit.
- Servicing: Refer all servicing to qualified service personnel. Do not attempt to repair the unit yourself.
- Placement: Place the amplifier on a stable, level surface. Avoid placing it near heat sources or in direct sunlight.
3. Setup
3.1 Unpacking
Carefully remove the amplifier from its packaging. Inspect the unit for any signs of damage that may have occurred during shipping. Retain the original packaging for future transport or storage.
3.2 Connecting Your Instrument
The RB108 features dual inputs: 0dB and -15dB. Use the 0dB input for instruments with passive pickups, and the -15dB input for instruments with active pickups or higher output levels to prevent signal clipping.
- Ensure the amplifier is powered off and the volume control is set to minimum.
- Connect your bass guitar to the appropriate input jack (0dB or -15dB) using a standard 1/4" instrument cable.
Figure 2: Close-up of the RB108 control panel, showing the 0dB and -15dB input jacks, SGT switch, and EQ knobs.
3.3 Power Connection
- Connect the supplied AC power cord to the AC INLET on the rear panel of the amplifier.
- Plug the other end of the power cord into a grounded electrical outlet.
Figure 3: Rear panel of the Ampeg Rocket Bass RB108, displaying the AC inlet and other connections.
4. Operation
4.1 Powering On/Off
- To power on, ensure the volume is at minimum, then flip the POWER switch to the "ON" position. The power indicator LED will illuminate.
- To power off, turn the volume to minimum, then flip the POWER switch to the "OFF" position.
4.2 Controls
- VOLUME: Adjusts the overall output level of the amplifier.
- BASS: Controls the low-frequency response.
- MIDRANGE: Controls the mid-frequency response.
- TREBLE: Controls the high-frequency response.
- SGT (Super Grit Technology): Engages the SGT overdrive circuit. On the RB108, this is a simple on/off switch. Other Rocket Bass models feature GRIT and LEVEL controls for more precise overdrive shaping.
- AUX IN: 1/8" stereo input for connecting external audio devices (e.g., smartphone, MP3 player) to play along with music.
- PHONES: 1/8" stereo output for headphones, allowing for silent practice. Connecting headphones mutes the main speaker.
4.3 Using Super Grit Technology (SGT)
The SGT circuit provides a warm, gritty overdrive reminiscent of classic Ampeg tube amps. Simply press the SGT button on the control panel to engage or disengage the effect. Experiment with your instrument's volume and tone controls to find your desired overdrive character.
5. Features Overview
The Ampeg Rocket Bass RB108 combines classic Ampeg aesthetics with modern functionality and portability.
- Portability: Designed to be lightweight, making it easy to transport for practice, lessons, or small gigs.
- Classic Ampeg Tone: Features a 3-band EQ for sculpting a wide range of bass tones, from deep lows to crisp highs.
- Super Grit Technology (SGT): A switchable overdrive circuit that delivers a warm, tube-like growl without sacrificing low-end clarity.
- Dual Inputs (0dB & -15dB): Accommodates both passive and active instruments, providing optimal signal handling.
- Auxiliary Input & Headphone Output: Enables silent practice and playing along with external audio sources.
- Durable Construction: Housed in a robust cabinet with a classic checkered Tolex finish and vintage grille cloth.
Video 1: An introduction to the Ampeg Rocket Bass series, highlighting its portability, Super Grit Technology, and classic design. This video provides an overview of the features shared across the Rocket Bass family, including the RB108.
6. Maintenance
Proper maintenance will ensure the longevity and optimal performance of your RB108 amplifier.
- Cleaning: Use a soft, dry cloth to clean the exterior. Do not use abrasive cleaners or solvents.
- Storage: When not in use, store the amplifier in a dry, temperature-controlled environment.
- Transportation: Always power off and unplug the amplifier before moving it. Use the integrated handle for carrying.
7. Troubleshooting
If you encounter any issues, refer to the following troubleshooting guide before contacting support.
| Problem | Possible Cause | Solution |
|---|---|---|
| No sound | Power not connected, volume low, instrument cable faulty, headphones connected. | Check power, increase volume, try a different cable, disconnect headphones. |
| Distorted sound | Input level too high, SGT engaged, faulty instrument/cable. | Use -15dB input for high-output instruments, disengage SGT (unless desired), check instrument/cable. |
| Humming/Buzzing noise | Ground loop, faulty cable, nearby interference. | Try a different power outlet, use shielded cables, move away from other electronics. |
8. Specifications
| Feature | Detail |
|---|---|
| Output Wattage | 30 Watts |
| Speaker Size | 1x8" |
| EQ | 3-Band (Bass, Midrange, Treble) |
| Inputs | 0dB, -15dB, Aux In (1/8") |
| Outputs | Headphone Out (1/8") |
| Special Features | Super Grit Technology (SGT) Overdrive |
| Dimensions (H x W x D) | 20 x 20 x 16 inches (approx.) |
| Weight | 27.4 pounds (approx.) |
| Material | Wood |
9. Warranty and Support
Ampeg products are designed for reliability and performance. For warranty information and technical support, please refer to the official Ampeg website or contact your local authorized Ampeg dealer. Keep your purchase receipt as proof of purchase for warranty claims.
For further assistance, visit the Ampeg Support Page.
