This blank PCB that can be used to connect a second sound board to Williams games without needing to modify cabinet wiring.  Assembly of this board will require soldering and separate purchase of the items below.   This listing is for the blank PCB only, parts below not included.   

Additional Parts Required (not included)

https://www.digikey.com/en/mylists/list/NV6H9PY4BS

https://www.ebay.com/itm/304482856805

https://www.ebay.com/itm/192562877297

Note - These less expensive speaker connectors will also work in place of the Digikey ones. 

https://www.ebay.com/itm/384940453644