Simple question about a schematic - Pignose

[AllThorUp]

Hi, folks. I was working on this old amp, and looking at the schematic I was wondering if someone could please explain to me what the 2 diodes marked "LED 1" and "LED 2" are doing in this circuit? Is it a clipping section? Because on my amp they were totally missing...  I was wondering what that might be doing to the tone of my amp and what might be expected if I were to stick some new LED's (or maybe some other kind of diode?) In those spaces?  If someone could please take a moment to learn me a little something about something I sure would appreciate it. Thanks!!

[g1]

You must have removed them, you found plain diodes there before, did you forget? 
The internet does not forget (usually):  https://www.ssguitar.com/index.php?topic=4093.msg32480#msg32480

Yes, they are clipping diodes.  Pretty much the same circuit is discussed and analyzed here:  (posts #1,4,7)
https://music-electronics-forum.com/forum/amplification/guitar-amps/mods-tweaks/50756-what-s-going-on-with-all-the-extra-diodes-here