The Joyo JE-303 3B EQ is a built-in electronics system for acoustic guitars — including a piezo pickup, a 3-band EQ (bass, mid, treble) and a tuner — that lets you shape your guitar’s tone and plug straight into an amp or PA. In detail: the 3-band EQ offers ±12 dB adjustment at roughly 75 Hz (bass), 750 Hz (mid) and 10 kHz (treble), so you can boost or cut lows, mids or highs to suit your playing style or venue acoustics. The built-in piezo pickup captures the acoustic guitar’s natural tone electrically, while the integrated tuner (with a tuning range from A0 to C8) and a low-battery indicator add convenience for live or studio use.

Overall, JE-303 is a simple, affordable, plug-and-play solution for acoustic players who want more control over their sound and the ability to plug in without needing an external mic or preamp.