The Sub Phatty has an automatic tuning procedure in it’s hidden functions. This can be accessed by pressing the Activate Panel while holding the Bank 4 button (include pictures from manual below).
In the Hidden Functions menu, press the Bank 3, Bank 4, and Patch 4 buttons. With all three lit, press the lowest C# key twice in succession, like clicking a mouse. The Activate Panel button will blink, Bank and Patch buttons will go dark, and the LEDs above the octave buttons will start blinking rapidly. You will hear very low tones coming from the Sub Phatty as it tunes itself, note after note, from lowest to highest.
We recommend running this calibration every 6-12 months or as needed.