To enter the onboard tuner on the Spark 2, simply power on the Spark 2 and hold the TAP/TUNER button to enter tuner mode.
While in tuner mode, the 3 Loopers LEDs will display if the string being played is in tune.
To exit tuner mode, press the TAP/TUNER or Preset button.
The onboard tuner is a chromatic tuner. if you're unsure whether your instrument is noticeably out of tune, we suggest connecting the Spark 2 to the Spark app (Tone Control) to check the note when tuning accurately.
You can also enter the tuner mode within the Spark app (Menu -> Tuner).