LED PIN confusion

[washburnx]

I don't know what is this simple problem will become a nightmare. Does anyone know what is the right way of connecting LED in the circuit? Does the cathode is always connected to negative or ground? please help me.

[defaced]

Unless you exceed it's reverse voltage, you won't hurt the LED by installing it backwards. So touch the leads to the pad to see which way makes it light up, then solder it in place.

[washburnx]

Thanks Mike, I really do what you said, to know everybody for the sake of the readers, I attached the schematic, I built the noise gate by Jon Gaines and it really works but I noticed the LED in the schematic it was reversed "encircled by red color", when I tested the project the LED doesn't lit but if i reverse its polarity and it will light. The big confusion in my mind is that why the designed made the LED reversed?

[defaced]

Probably because even smrt people screw up sometimes.