PROEL CO12W4 User Manual page 11

3. Select the input voltage by connecting the audio signal line to the
neutral (black terminal cable) and the positive (coloured) terminals in
correspondence to the required voltage level (brown 25V; red 70V;
orange 100V):
4. For CO12W4 and CO20W7:
With the help of a screwdriver, remove the rubber protection of the
power selector placed on the back of the unit. Select the output power
level required and replace the rubber protection. Position the column
and tighten the fixing bolts.
For CO20WL4 and CO30WL6:
Select the output power level required by using the selector placed at
the base of the column. Position the column and tighten the fixing bolts.