Gearank

The Korg CA-40 has a handy battery saving feature where it turns itself off when left on unused for 20 minutes.

It's not specifically designed for guitar but has found a place with guitarists who also play other instruments from ukulele to brass and woodwind, or who share it with others at home who play those instruments.

Although it does have a bypass output jack which Korg say is good for live use, like all handheld tuners it's not particularly practical for guitarists to use during a live performance setting but is fine for tuning in between sets, home use and practice sessions.

Specifications:

• Tuning Accuracy: ±1 cent
• Tuning Range: A0 (27.50 Hz) to C8 (4186.01 Hz)
• Reference Pitch: A4 = 410 Hz to 480 Hz (1 Hz steps)
• Tuning Modes: Meter mode (AUTO), Sound Out mode (MANUAL)
• Tone Generator Range: C4 (261.63 Hz) – C5 (523.25 Hz): 1 octave
• Display: LCD needle-style
• Connectors: INPUT jack (1/4” monaural phone jack), OUTPUT jack (1/4” monaural phone jack)
• Power Supply: Two AAA batteries (3V)
• Dimensions: 3.94” (100 mm) x 2.64” (67 mm) x 0.67” (17 mm)
• Weight: 0.19 lbs (88 g) - includes batteries

Pros

Value for money is one of the main features that make this tuner appealing. It is reported to work well on all kinds of fretted instruments including bass guitar.

Cons

Some people have reported issues with the needle not stabilizing but others have suggested this may indicate a need to change the batteries.

Overall

Unfortunately the Korg CA-40 has been discontinued so if you want a newer option then see our recommended Handheld Tuner and other options in our guide to The Best Guitar Tuners.