Modding a NES to play Famicom carts

[MarioMania]

Not with a Converter

I saw a youtube video like I don't know when

He modded a NES, Soldered wires to the Cart Pins to the Famicom Converter

Modded the audio for extra sound

Can't fine it on youtube, any  help?

[FAMICOM_87]

years ago I made a MOD and called it Fami-NES
https://www.famicomworld.com/forum/index.php?topic=8910.0

[muramasa]

aarkay14 did this. I was really impressed with how clean it was.
https://www.famicomworld.com/forum/index.php?topic=14506.0

aarkay14 used to have kits (maybe they still do)
https://www.famicomworld.com/forum/index.php?topic=14580.0