Boss EH-2 Enhancer in overall good condition. Made in 1990. Runs on 9v battery or adapter (not included).

It’s a dynamic enhancer / harmonic enhancer. It brings out clarity, presence, and high-frequency harmonics so the guitar (or bass) cuts through a mix better and sounds more defined—especially useful after distortion/overdrive or long pedal chains that can muddy the tone.

Controls:

MIX — Balances dry signal with the enhanced signal. Center (0) is dry only; right (NOR) adds the enhanced signal in normal phase; left (INV) adds it in inverted phase.

FREQ — Selects the frequency range being enhanced (generally more useful below noon; higher settings can get very bright or less audible).

SENS — Sensitivity/threshold for how strongly the effect responds to your playing dynamics (harder picking triggers more enhancement). There’s an LED that lights with the effect activity.