Very cool post. Not being a tech. When removing the 4 parts, do you place a jumper wire in it's place to complete the circuit, or just remove the parts?

pleat

I haven't had a chance to completely figure out what this mod does yet, but two of the caps that he is removing will actually increase the treble response of the amp. C116 and C118 are there to eliminate high frequencies, like radio signals and oscillations. Removing them will not help tame the high end of the amp.

Removing R127 is the only thing that I see will let less high frequency enter the circuit. And don't replace it with a jumper or you will have the exact opposite effect.