KORG DT-4 chromatic tuner

From Amazon

A New Style with Lights to Indicate Pitch The DT-4 is a unique chromatic tuner that displays the note closest to the input note in the center and the pitch with a light around the outside of the unit. Despite its compact size that fits in the palm of your hand, the rotating light and large, easy-to-read note display enable highly accurate tuning across a seven-octave range from A0 (27.50 Hz) to C8 (4186.01 Hz). It also features a calibration function that allows you to set the reference pitch between 410 Hz and 480 Hz (in 1 Hz increments). Each function selection switch is conveniently positioned for easy operation, ensuring ease of use.

Despite its compact size, this high-performance chromatic tuner features a unique lighting system that makes tuning easy. Equipped with three innovative tuning modes unique to LEDs. Wide tuning range from A0 to C8 (7 octaves). Equipped with a calibration function that supports a variety of concert pitches. A built-in condenser microphone supports acoustic instruments. Energy-efficient design.

Three innovative tuning modes unique to the LED display system. The DT-4 offers three types of tuning: strobe, mirror, and meter, depending on how the green light on the tuning indicator illuminates. It also features a red triangular tuning guide that supports pitch and precise tuning.

Strobe Mode When sound is detected, the rotating green light stops, indicating precise tuning. If the input note is higher than the desired pitch, the LED light rotates clockwise; if it's lower, it rotates counterclockwise. When precise tuning is achieved, the two tuning guides also light up simultaneously.

Mirror Mode This innovative optical mirror mode indicates precise tuning when the two green lights on the bottom left and right overlap. When the mode is selected, the bright green light moves to the right of center if the input note is high, and to the left if it's low. The difference between the bright and light green indicates the deviation from precise tuning.

Meter Mode Tune your instrument by aligning the bright green light with the red tuning guide in the center. While a typical needle meter always starts from the lowest tuning point, the DT-4's green light illuminates at the pitch of the input instrument, allowing for quick tuning.

Energy-Saving Design In strobe mode, the DT-4's rotating green light dims after approximately 30 seconds of no input sound. It also automatically shuts off if the power is on and there is no input sound for approximately 10 minutes, helping to conserve battery power.