Peavey V12 - Manual (Page 21)

p. 21
group output module —matrix, aux, group
mono-matrix features
Mtx master and GRP master LED indicators
Indicates the operation of this set of controls within this output section.
When the MTX MASTER LED (red) is illuminated, ALL of the controls
within this Upper Control Section will affect the matrix output. If the GRP
MASTER LED (Group) is illuminated (Only one LED will be illuminated),
ALL of the controls within this Upper Control Section will affect the
group output and feed to the Group Assignment section.
write-on strip
Will provide a number for this group output as well as providing a write
in area for the customer or a mounting surface for the customers mask-
ing tape labeling.