AD828 Operational Amplifier Front Stage Amplifier Board is  ultra-compact preamplifier board is designed for high-sensitivity sound pickup using a piezoelectric ceramic chip. Ideal for musical instruments like guitars, erhus, and similar acoustic setups, the chip responds to solid-borne vibrations while filtering out airborne noise—minimizing feedback and self-excitation.

AD828 Operational Amplifier Board is built with either a high-fidelity AD828 or TDA1308 audio op-amp, it offers low-voltage operation (3.8V–15V) and a dual-channel design, making it perfect for stereo setups or single-channel applications with noise isolation.

Note: To adjust gain, change resistor R5 (5k–150k Ω). Higher resistance = higher gain. If using a through-hole resistor, remove the original SMD resistor and solder the new one to the reserved pads.

Features:

1. Solid-Vibration Sensitivity: Piezo ceramic pickup detects vibrations from solid surfaces with high accuracy — ideal for stringed and percussive instruments.
2. Noise Reduction: Rejects air-borne sound, reducing environmental noise and preventing feedback or whistling caused by self-excitation.
3. Dual Channel Design: Two-channel setup for stereo or dual mono operation; if using only one channel, ground the unused input to avoid signal interference.
4. Low Voltage Operation: Optimized for 3.8V–15V DC input; suitable for direct lithium battery use.
5. Hi-Fi AD828 Op-Amp: Uses the AD828 “fever-grade” op-amp for low-noise, high-fidelity signal amplification.
6. Ultra-Compact Size: Extremely small form factor allows easy installation in confined instrument enclosures or DIY projects.
7. Battery or Linear Supply Only: No onboard regulator; must not be used with switching power supplies to avoid noise or interference.

Package Includes:

1 x AD828 Operational Amplifier Front Stage Amplifier Board