Andoer EQ-7545R Piezo Pickup Acoustic Guitar Preamp Amplifier Equalizer Tuner User Manual

1. Product Overview

The Andoer EQ-7545R is a high-quality piezo pickup system designed for acoustic guitars. It features a built-in 4-band equalizer and volume control, allowing users to easily electrify and amplify their acoustic guitar's sound. This pre-wired system is designed for straightforward assembly and includes a battery box and a low battery indicator for convenience.

Key Features:

• Integrated 4-band equalizer (Bass, Middle, Treble, Presence)
• Volume control knob
• Pre-wired for simplified installation
• Dedicated battery box for a 9V alkaline battery
• Low battery indicator LED
• Connecting wire with 2.5mm plug included

Figure 1: Front view of the Andoer EQ-7545R preamp unit with its controls and output jack cable.

2. Package Contents

Please verify that all items listed below are included in your package:

• 1 x Pre-Amp unit with integrated pickup
• 1 x Connecting wire with 2.5mm plug (for the piezo pickup)
• 1 x 9 Volt battery box (Note: 9V battery not included)
• 1 x Mounting base with adhesive sticker
• 4 x Mounting screws

Figure 2: All components included in the Andoer EQ-7545R package, showing the preamp, wiring, battery box, and mounting hardware.

3. Safety Information

• Professional Installation Recommended: Installation of this product requires modifications to your acoustic guitar, including cutting into the instrument's body. It is highly recommended that installation be performed by a qualified guitar technician to prevent damage to your instrument.
• Battery Safety: Use only 9V alkaline batteries. Ensure correct polarity when inserting the battery. Remove the battery if the unit will not be used for an extended period to prevent leakage.
• Avoid Moisture: Do not expose the unit to water or excessive moisture.
• Handle with Care: The electronic components are delicate. Handle the unit carefully during installation and operation.

4. Setup and Installation

Installing the EQ-7545R requires precision and careful modification of your guitar. Proceed with caution or seek professional assistance.

4.1. Tools Required:

• Measuring tape or ruler
• Pencil or marker
• Dremel tool or small saw for cutting wood
• Drill with appropriate bits
• Screwdriver
• Sandpaper or file
• Soldering iron (optional, for output jack if not pre-wired)

4.2. Installation Steps:

1. Measure and Mark: Carefully measure the dimensions of the preamp unit and the battery box. Choose a suitable location on the side of your guitar (typically the upper bout for right-handed guitars) for the preamp and a separate location for the battery box. Mark the outlines precisely. Refer to the dimensions image for accurate measurements.


Figure 3: Detailed dimensions of the EQ-7545R preamp unit, crucial for accurate cutting.

2. Cut Openings: Using a Dremel tool or small saw, carefully cut the marked openings for the preamp and battery box. Ensure the cuts are clean and precise to allow for a snug fit. Sand the edges smooth.
3. Install Preamp: Insert the preamp unit into its designated opening. Secure it with the provided mounting screws.


Figure 4: Side view of the preamp unit, showing its depth and construction.

4. Install Battery Box: Insert the battery box into its opening. It may be secured with screws or adhesive, depending on the design. Ensure the battery compartment is easily accessible for future battery changes.


Figure 5: Rear view of the preamp unit, illustrating the battery compartment and internal wiring.

5. Install Output Jack: Drill a hole for the 6.35mm output jack, typically on the lower bout or end block of the guitar. Secure the jack.


Figure 6: Close-up of the 6.35mm output jack, which connects the preamp to an amplifier.

6. Connect Piezo Pickup: The piezo pickup element is designed to be placed under the saddle of your guitar's bridge. Carefully lift the saddle, insert the piezo strip, and replace the saddle. Ensure the connecting wire (2.5mm plug) from the piezo pickup is routed to the preamp unit and securely connected.
7. Wire Connections: Connect the wires from the battery box and the output jack to the appropriate terminals on the preamp unit. The system is pre-wired for ease of assembly, but ensure all connections are firm.


Figure 7: The preamp unit shown with the output jack connected, illustrating the complete wiring setup.

8. Insert Battery: Open the battery compartment on the preamp unit and insert a fresh 9V alkaline battery, observing correct polarity. Close the compartment.


Figure 8: The preamp unit with the battery box removed, showing the internal space for the 9V battery.

9. Test: Connect your guitar to an amplifier and test the system. Adjust the volume and EQ controls to ensure proper functionality.

5. Operating Instructions

5.1. Controls Overview:

• Volume Knob: Adjusts the overall output level of the preamp. Turn clockwise to increase volume, counter-clockwise to decrease.
• Bass Slider: Controls the low-frequency response. Boost for a fuller, warmer sound; cut for a tighter, less boomy sound.
• Middle Slider: Adjusts the mid-range frequencies. Boosting can make the guitar sound more prominent in a mix; cutting can reduce harshness.
• Treble Slider: Controls the high-frequency response. Boost for brighter, more articulate tones; cut for a smoother, less piercing sound.
• Presence Slider: Adjusts the very high-frequency range, affecting the clarity and attack of the sound. Boost for more sparkle; cut to soften the attack.
• Battery Check Button/LED: Press this button to check the battery status. The LED will illuminate if the battery has sufficient power. If the LED does not light up or is dim, the battery needs replacement.

5.2. Adjusting Sound:

Experiment with the EQ sliders to find the desired tone. Start with all sliders in the middle (flat) position and make small adjustments. The effect of each band can vary depending on your guitar, playing style, and amplifier.

5.3. Battery Replacement:

When the low battery indicator suggests a weak battery, or if the unit stops functioning, replace the 9V alkaline battery. Open the battery compartment, remove the old battery, insert a new 9V battery ensuring correct polarity, and close the compartment securely.

6. Maintenance

• Cleaning: Use a soft, dry cloth to clean the surface of the preamp unit. Avoid using abrasive cleaners or solvents.
• Battery Life: Battery life varies depending on usage. Always carry a spare 9V battery, especially for live performances.
• Storage: If the guitar will not be used for an extended period, remove the 9V battery from the preamp to prevent potential leakage and damage to the electronics.
• Connections: Periodically check all internal and external connections for tightness and corrosion.

7. Troubleshooting

Common Issues and Solutions:

• No Sound Output:
  • Check if the 9V battery is correctly installed and has sufficient charge. Replace if necessary.
  • Ensure all internal wiring connections (piezo to preamp, battery to preamp, preamp to output jack) are secure.
  • Verify that the guitar cable is properly connected to both the guitar and the amplifier.
  • Check the amplifier's volume and settings.
• Poor Sound Quality / Buzzing / Hum:
  • Adjust the EQ sliders. Extreme settings can sometimes introduce unwanted noise.
  • Ensure the piezo pickup is correctly seated under the saddle and making good contact.
  • Check for any loose wiring or poor shielding inside the guitar.
  • Test with a different guitar cable or amplifier to rule out external equipment issues.
• Low Output Volume:
  • Increase the volume knob on the preamp.
  • Check the battery charge. A weak battery can result in low output.
  • Ensure the piezo pickup is properly installed and making full contact with the saddle.
• Feedback Issues:
  • Reduce the volume on the preamp and/or amplifier.
  • Adjust the EQ settings, particularly cutting the middle and presence frequencies.
  • Avoid standing directly in front of the amplifier at high volumes.
  • Consider using a soundhole feedback suppressor.

8. Specifications

9. Warranty and Support

For specific warranty details, please refer to the retailer or manufacturer's official website. Warranty terms and conditions may vary based on your region and point of purchase.

For further assistance or technical support, please contact the retailer where you purchased the product or visit the official Andoer store online:

Visit the Andoer Store on Amazon