Automatic Mode

• 1). Turn the unit on. Press and release the "Power" button located below and to the left of the display screen.
  
  
• 2). Press the "Mode" button to select bass or guitar in automatic tuning mode. Watch the liquid crystal display (LCD) to determine which mode is selected with each button press. Initial startup mode for the GU20 is automatic guitar.
  
  
• 3). Pluck the instrument's lowest pitched string. Watch the LCD needle display -- as well as the light-emitting diodes (LEDs) above the display -- to determine whether the note is sharp or flat. The string and pitch the tuner is attempting to match shows in the lower-left corner of the display. Adjust the pitch of each string to bring the display needle to zero and illuminate all three LEDs.
  
  

Manual Mode

• 1). Prepare the tuner following the first two steps of the previous section.
  
  
• 2). Press the "Adjust" button until the unit displays the number and pitch of the string you wish to tune.
  
  
• 3). Pluck the string. Adjust the string's pitch until the tuner's needle points to zero and all three LEDs are lit.