Genesis:Triple Bypass Mod Sega CDX

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This document will serve as clear step-by-step instructions for installing the 3BP on the Sega CDX.

Jumper Settings

Solder the “2” jumpers.

If removing the solder 2.2K resistor for PSG as detailed below, solder the d-right jumper.

Top Side Component Removal

Remove FML, 32X, PSG Components

Remove the components boxed in red below. R81 is optional, but makes connecting PSG easier (make sure to solder the d-right jumper if you do this!).

CDX 3BP Component Removal, Top, 1

Remove RGB Output Components

Remove the components boxed in red. The components in yellow must be removed if CVBS restoration is not desired.

CDX 3BP Component Removal, Top, 2


Remove Cart to CD/PCM audio mixing components

Remove the components shown in red, and replace R75 and R76 with 4.7K 0603 or 0805 size 1/8W (or better) resistors.


CDX 3BP Component Removal, Top, 3


Bottom Side Component Removal

Remove FMR and PSG AC Coupling Capacitors

Remove the components boxed in red.

CDX 3BP Component Removal, Bottom, FMR and PSG


Remove RGB Encoder Input Resistors

CDX 3BP Component Removal, Bottom, RGB Encoder Input


Installation Process

Audio Input Connections

Connect the 3BP audio input pads to the points labeled below. Take note that there is NO input for "CL" or "CR." CDX 3BP Audio Input Connection Points

RGB Input Connections

Connect the 3BP RGB input pads to the points labeled below. Refer to the image shown in component removal above for TTL Sync if CVBS restoration is not desired. CDX 3BP RGB Input Points

5V and GND Input Connections

Below are suggested connection points for 5V and GND. Other points may also be suitable.

CDX 3BP Power Supply Points

Audio Output Connections

Connect the 3BP Left and Right audio outputs to the points shown below.

CDX 3BP Audio Output Points

RGB Video Output Connections

Connect the 3BP RGB outputs as shown below. If not restoring CVBS, connect the "S75" output pin to the through hole for C46(-).

If not restoring CVBS, the installation should be finished at this point. If not, see the next step.

CDX 3BP RGB Out Connections

CVBS Restoration Points

If restoring CVBS, use the points indicated below. The 3BP V2Plus has 511 ohm resistors connected to the "R0,"G0" and "B0" pads. Otherwise, use a value between 470 and 511 ohms to connect the RGB output to the pads indicated below.

CDX 3BP CVBS Restoration Points


Installation Example

Below is an example installation of the 3BP, but not necessarily the only correct way to do one.

Example Installation of a 3BP V2 Plus on the Sega CDX