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Is it just me, or is the input cap on the hipster schematic backwards? Shouldn't the positive side go towards the signal? Is there a reason for this?

I tried googling silicon fuzz face and found many versions of the schematic with the cap either way! Seems like its rather random.

So I built an afterlife a few weeks ago, with all the stock values, no subs. I thought it was working, but seemed very minimal so I looked at some video demos, which made it seem a lot more apparent. I checked it my Vactrol is correct, and it is, so I took a standard LED and bent the leads out so they would contact the LED leads on the vactrol, and the led lights up. No guitar signal present, nothing. the brightness doesn't change with guitar signal, so obviously the effect is not working. I tried numerous other TL072s with the same result. These are all from the same seller and I've used them in many projects (eurorack synth and stompbox) without previous issues.

So I tried a tl082 from my parts bin, and low and behold the LED is off, until a signal is present, and it seems to react as expected. The effect is a bit noisier as well, but sure works as I have expected.

This made me think maybe my supply of DIP TL072's is at fault, so I made an adapter for a SOIC tl072, and it has the exact same response as the DIP ones.

So what could possibly be at fault here? Why would these chips work in so many other projects but not the afterlife? What can I test to give some better ideas? I've checked voltages, and don't see anything obvious.

TL082:
4.41v   -|1   8|- 8.76v
4.40v   -|2   7|- 4.40v
2.22v   -|3   6|- 4.40v
0.01v   -|4   5|- 4.40v

TL072
5.39v   -|1   8|- 8.79v
4.60v   -|2   7|- 4.20v
0.79v   -|3   6|- 4.43v
0.01v   -|4   5|- 4.43v

All measured with respect to the ground on the DC jack