Proposition distortion question (first-timer with clipping LEDs)

[mkstewartesq]

I thought I would ask this as a general question before starting a troubleshooting thread because, depending on the answer, there may be no trouble to shoot.

I finished this pedal and it is working on the auditorium (test) platform. To my ears, it sounds great and even the compression supplied by the “must be within certain specs” J201 seems to be working well – almost endless sustain.

However, no matter how many pedals you build, I am living proof that you can still be a newbie with respect to certain things. This is my first build to use clipping LEDs. My question: are the green and red LEDs on the left side of the board (LED1 and LED2 on the BOM, circled in the picture below) supposed to light up while playing? If so, they aren’t. The two red LEDs in the dead center of the board (LED3 and LED4) light up just as I would expect them to - but I’m not sure if the green and red LED on the left are supposed to be doing anything or not. If it helps, schematic attached.

Thanks,

Mike

 

[drgonzo1969]

The green never lit up on mine either but it still sounds great. I read another build report with the same results on here somewhere too

 

[jwin615]

LEDs can clip without illuminating, at least to the naked eye.
If you're familiar with compressors, in the pro audio sense and "clipping/distortion" aside...
A diode can act as a source of clipping. But it can also act as a source of limiting. Think of a brick wall limiter, near zero attack and release.
If LED/diode is catching only the brief transients(voltage spikes) of a signal, it may not illuminate but will still clip/limit the spike. Keep in mind, most diodes don't produce light, only heat.
To produce light with an LED you need not the specific voltage(transient spikes), but the necessary current as well. It's common for guitar pedals to not produce enough current to illuminate an LED. In some instances, you should place a camera on it in a dark room and catch a brief blip that would be unperceived by the naked eye.
Sometimes you just have to trust that they are working.