Peterson Goodwyn opens up an 1176 and takes a close look at one of its most familiar controls. The numbers on the ratio knobs, 4, 8, 12, 20, don't actually set a fixed compression ratio, and understanding why changes how you think about the whole unit.
Human hearing is logarithmic. That means equal steps in perceived volume represent exponentially larger jumps in actual signal strength. A signal that sounds 20 dB louder to our ears, represents 100 times more voltage arriving at the compressor's gain element. The circuit operates with linear voltage and has no way to account for that gap. So the effective ratio increases with input level rather than staying fixed. You can't lock in a single ratio with these switches, because the ratio itself shifts depending on how hard you drive the unit.
What the switches are actually doing is lowering the threshold, letting more signal into the sidechain and triggering compression earlier. The 1176 has always had a threshold control. It's just been called something else.
Peterson also points out that the famous all-buttons-in mode doesn't require all four switches. Pressing only the first and the fourth gets you the same result.