The earliest “blue-line” SVTs like the one shown here (which has since been updated with KT88 tubes) had control panels engraved with blue lines and text, though Ampeg later switched to a more legible black format.
SVTs of this era had volume, treble, midrange, and bass knobs for the first channel, while channel 2 only had volume, treble, and bass.
The combined air-moving capability of eight 10" speakers reacts faster to transients than fifteens or eighteens.
The result is sound you can feel, that the audience can feel and that truly delivers what you want out of a bass rig.
Because we learned early on that 10" speakers work much more efficiently than fifteens or eighteensand if you put eight 10" speakers together, you can move a much larger column of air.