Genesis Triple Bypass

The “Triple Bypass” is both an RGB and audio bypass board, designed by db Electronics that can be installed in any Sega Genesis / Mega Drive console.  Installation will essentially be two mods that connect to the same board:  An RGB bypass and Sega Mega Amp installation.  This is considered an expert-only mod and will (in most cases) disable composite video output.

Important note:  At this time, it is not recommended that a triple bypass is done in Genesis / Mega Drive model 1 consoles (except VA7).  This is for two reasons:

– The audio output of most Genesis 1 consoles is already excellent, not requiring a bypass.

– There is an issue with “RAM noise” on the motherboards;  Performing an RGB bypass removes analog noise such as jailbars, but ends up amplifying the RAM noise interference, causing it to look worse.  Simply lifting the subcarrier pin (disabling composite video) on most model 1’s will remove a great deal of interference from the output and it will be a large improvement over stock video output.

 

Video

The Triple Bypass incorporates a THS7374 video amplifier for the RGB video bypass, pushing the Genesis one step closer to perfect video output.  Depending on your model, you may need to lift the RGBs pins from the board, or even re-route the crystal oscillator path to remove the final bit of video interference.

 

Audio

One of the most exciting features of this board is it’s integrated Mega Amp 2.0, originally designed by Ace and tweaked by René.  This means anyone installing the Triple Bypass in a Genesis 2 or 3 will now have the best possible audio and video quality and will no longer have that awful, tinny sound output!  Also, this will allow for stereo output from a Genesis 3, making it a great choice for Genesis users with limited space!

 

Purchase

Triple bypass boards will be available to purchase from a few resellers.  Links to whoever will carry stock (not just 1-off builds) will be added here:

https://insurrectionindustries.com/

 

Download

Main Page:  https://github.com/db-electronics/triple-bypass-kicad
BOM:  https://github.com/db-electronics/triple-bypass-kicad/tree/master/triple-bypass/bom

 

Bill Of Materials:

Here’s saved BOM’s that I created, but might be out-of-date and some parts EOL (different BOM per audio revision).  They can be used as a guide to help get ordering started, but you’ll need to cross-check with the main BOM listed above.  Feel free to create your own octopart BOM and sumbit it here, to make other people’s ordering easier:

Sega Triple Bypass ASIC:  https://octopart.com/bom-tool/mam99sv6
Sega Triple Bypass GOAC:  https://octopart.com/bom-tool/LQCsRW95
Sega Triple Bypass YM2612:  https://octopart.com/bom-tool/N0G5JHIj

 

Installation Instructions:

Installation instructions and a dedicated guide page coming soon.  Please reference the Mega Amp thread for the audio installation:  http://www.sega-16.com/forum/showthread.php?31989-Take-your-Genesis-audio-to-the-next-level-The-Mega-Amp-2-0-is-here!  For the video bypass, you can follow the same basic guide as the original Genesis RGB bypass:  Here’s some detailed pictures of installations on a few different model Genesis consoles.  If you reference the above guides and match the wire color / installation points, you should have all the info you need:

Genesis 2, VA1
Genesis 2, VA4
Genesis 3, VA1
Leon K’s alternate install method:  https://twitter.com/leonkiriliuk/status/1058535260756078594

 

HD Retrovision Compatibility:

Triple Bypass was designed with the HDRetrovision stuff in mind. The “composite video” pin will always output 75 ohm cync, regardless of what the jumper is set to. That means if you’re installing it with the DIN soldered to the board, the connection is already there. If you’re installing it into a Genesis 2 or 3, just solder a connection from the cvbs pin on the board to cvbs on the main DIN. This obviously won’t enable composite video, but it’ll guarantee compatibility will all cables, including RGB SCART cables that get sync from composite video.

 

 

This page will be updated with more info and more installation pictures / guides as soon as possible!