This question has been asked by one of our customer and I thought it my be useful to other people:
While in the main screen, press and maintain the SEL button for around 3 seconds.
A parameter should appear "Prog" or "roff" on the SV screen.
Release the SEL button. Then press it again normally - that will switch between the different parameters.
After pressing few times, you should reach "AT" (auto tune settings) which look like more "A7 0" on the screen.
"0" being the parameter at which it is set at:
2: low PV
You want to change it to "1" with the arrow key.
You will then have "A7 1" displayed.
Then, press and maintain the select button until coming back to the main screen.