JVC RV-NB100B Instructions page 29

Using the main unit
1
Press and hold the [o] button on main unit
for more than 2 seconds until "G AMP" is
displayed.
Each time you press and hold the button,
0
the function switches between super
woofer volume adjustment ("SW VOL"
appears on the display window) and the
guitar tone adjustment.
2
Turn the [SUPER WOOFER VOLUME]
control to the left or right to select the tone
of the guitar.
(Turn)
29