No soldering was needed for the Darksoft multi on a Marvel vs Capcom board, so if you can find one of those that's already dead, I think that's the easiest way to go.
Greetings everyone, I'm a long time lurker but first time poster. I've learned a lot about arcade hardware here and I look forward to finally contributing.
I just finished converting a dead CPS2 board to a Darksoft multi, and it's fantastic!