On the left side of the control panel above the Mod Wheel, find the MASTER section, with a Volume and a Tune knob. Press the AUTO TUNE button beneath these, which will bring up the Auto Tune display. Press AUTO TUNE again to start the tuning process.
On the display, you will see each individual oscillator, pulse width, and filter tuned in turn. This takes about three and a half minutes, during which you won't be able to play the unit. (Later, you can save time by tuning only the oscillators if you wish, by pressing the button under OSCFRQ in the display.)
Once the unit is tuned, you'll see a chart showing the results of the tune. A “ T ”
under each voice number shows that the voice was properly tuned. There is one row
showing the VCA tune status and one row showing the Oscillator/Filter tune status
(more on this later). After the unit has warmed up some more, if you hear something
off-key, you may press AUTO TUNE again.
The A6 also automatically tunes unused voices in the background without
interrupting playing. This is called Background Tuning. In addition, the A6 monitors
the temperature of the analog hardware and adjusts tuning to compensate for
temperature changes. This is called Temperature Tuning.