1st Production Version Big Box Rats
Tone Control - Highs are increased as knob is turned clockwise using a Linear taper pot
Pro Co Sound Logo with "Sound Inc" vertically on side
Fluted silver center knobs on earliest versions
"Fringe" on Rat logo with all capital letters on very early models (1st 100?)
Changed to different Rat logo (bottom pic) with lower case #a & t" and no "fringe"
Very early models used Tantalum caps (small blue and brownish orange caps)
No battery door on bottom
Notice in photos the Volume, Tone and Distortion lettering is closer to the knobs on the 78' & 79' than the later models.
1978 Big Box Rat
1979 Big Box Rat
1981 Big Box Rat