Is There A Mute Function On The Astell&Kern; I Can't Adjust The Volume - Astell & Kern AK100 Introductory Manual

 5. Is there a mute function on the Astell&Kern?
o The volume "Mute" feature is not supported on the Astell&Kern.
o To adjust the volume quickly, either rotate the Volume Wheel to adjust
the volume or touch the LCD display and swipe to the left or right for
adjustment.
 6. I can't adjust the volume.
o By default, the volume can be controlled with the Volume Wheel located
on the right side of the Astell&Kern, even when the LCD is turned off.
o If the volume wheel does not adjust volume levels when the LCD is
turned off, the volume lock may be turned on. To turn on/off the volume
lock, please navigate to: Settings -> Advanced -> Lock for adjustment.