Genesis:Triple Bypass Mod

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Exclamation-triangle-fill.svgThis should be considered an expert-only mod and will (in most cases) disable composite video output.


The "Triple Bypass" mod is a board that bypasses the audio circuit, video circuit, and optionally, the Model 1 DIN of the Sega Genesis / Mega Drive. It was originally designed by db Electronics, but has become a true open source project with many amazing contributors. There are also versions for the Master System, Nomad, and others being made by members of the community. The latest version's source files can be found on Tianfeng's GitHub (or Zaxour's improved remix) or it can be purchased from Insurrection Industries or RetroGamerStuff.

For technical details on how the Triple Bypass mod works, please see the Genesis:Triple Bypass Mod Technical Details page.

Benefits

Although Genesis consoles can output RGB natively, all models will absolutely benefit from a full audio and video bypass. Model 1 Genesis consoles will have a big upgrade in video quality and while the audio is already excellent, you'll have a slightly quieter noise floor if you bypass that too. Model 2 and 3's generally have decent video, but not good (or just mono) audio. 

Jailbar Fix

GenesisArcadeTVRGBBypassCompare-small.jpg
GenesisArcadeTVRGBBypassCompare.png

While simply lifting the subcarrier pin from the VDP will show a noticeable reduction in jailbars in most revision Model 1 units. It's not as good as a full bypass.

As shown in the pictures on the right, performing this bypass will help remove analog video jailbars from the Genesis' output image. All analog video consoles will always have some noise on the signal and the Genesis / Mega Drive are some of the worst of the bunch.

Moving the Signals Off the Motherboard

All Genesis consoles have motherboards with a good amount of interference in the audio and video signals. Tapping the audio and video signals from their sources and moving them off the motherboard seems to be a great improvement to the signals. The circuits and components used in the Triple Bypass are either equal to or better than what's found on the board, while also offering more options. Audiophiles can choose between filtered and unfiltered sound and a low-pass filter can be toggled on the video output.

Installation Guides

Model Triple Bypass Guide Audio Fix Post-Bypass Color Fix Notes
Model 1
Genesis Model 1.png
"VA0" Guide Guide
VA1
VA2
VA3 N/A
VA4 N/A
VA5 N/A
VA6 N/A
VA6.5 N/A
VA6.8 N/A
VA7 N/A
Model 2
Genesis Model 2.png
VA0 N/A For all versions of the Genesis 2 except the VA4,

a bottom-install is recommended.

VA1 N/A
VA1.8 N/A
VA2 N/A
VA2.3 N/A
VA3 N/A
VA4 N/A
Model 3
Genesis Model 3.png
VA1 N/A
VA2 N/A
Sega CDX
Sega CDX.png
CDX N/A

Links