The Mega Amp 2.0 Pro by Ace and Villahed94 is a mod to bypass the original Genesis circuitry and replace it with a cleaner audio amp. This also allows all Genesis models to drive headphones and achieve a higher volume output than the original model 1 Genesis. Depending how you choose to set it up, you can have 3.68KHz low-pass filtering for Genesis Model 1-like audio or an unfiltered setup. It also allows for Sega CD audio mixing.
Genesis Installation
The installation procedure can be found in the official manual.
CDX Diagrams
Credit to Voultar for figuring these points out and creating the diagrams.
