- A compact tuner designed specifically for guitar and bass, with excellent performance and convenient functionality.
- Large, high-precision meter-type display for stable tuning indication.
- Quinta-Flat Tuning mode allows dropped tunings from one to five semitones.
- Supports tuning of seven-string guitars and six-string basses.
- Sound Out function lets you produce a reference tone from the internal speaker.
- Bypass function.
- Auto Power Off function saves the battery even if you forget to turn off the tuner.
- Memory Backup function.
- Approximately 85 hours of continuous use.

Dedicated guitar and bass tuner with large LCD for easy viewing
The GA-40 is a dedicated, easy-to-operate guitar/bass tuner with automatic pitch detection. In Guitar mode it supports seven-string guitars (7B through 1E), and in Bass mode it supports six-string basses (Low-B and Hi-C). With the precision you expect from KORG, the GA-40 indicates the pitch quickly and accurately. The LCD needle-style display provides both the accuracy of an LCD as well as the easy viewing of a needle indicator, and the display has been enlarged for even better visibility. You can also use the built-in high-sensitivity microphone to tune an acoustic guitar.

Sound Out function produces a reference tone from the internal speaker
In addition to letting you tune visually using the meter, the GA-40 provides a Sound Out function that plays a reference tone through the internal speaker, letting you tune by ear. Each time you press the Sound switch, the tone will cycle through 7B → 6E → 5A → 4D → 3G → 2B → 1E in Guitar mode, or through LB → 4E → 3A → 2D → 1G → HC in Bass mode.

Quinta Flat Tuning mode
To support the dropped tunings used in heavy metal styles to produce a powerfully massive sound, the GA-40 provides a Quinta Flat Tuning mode that lets you detect dropped tunings of one through five semitones. This lets you tune super-long scale guitars that extend below the pitch range of conventional guitars.

Conveniently thin and compact
The GA-40 gives you convenient guitar and bass tuning functionality in a pocket-sized package, making it easy to tune whether you`re on stage or in the studio. An output jack (bypass) has been added, making it easy to check the tuning even while you`re performing.

The stand on the back lets you place the tuner on any surface.

Auto Power Off function
The Auto Power Off function automatically turns the power off after the unit has been left on for twenty minutes, preventing the batteries from running down needlessly.

Approximately 85 hours of continuous use
The GA-40 is designed for long battery life, and allows approximately 85 hours of continuous use (continuous A4 input, Meter mode, zinc-carbon batteries).

*Even if a sound is within the detectable pitch range, detection may be unsuccessful for instrumental sounds that contain a large number of overtones or that decay rapidly.