Hi guys I'm also trying to hookup a line out to a Spike-2 game and having issues. The info above is for the Spike CPU board, not Spike-2. I can't find a CN27 on the Spike-2 CPU boards on my Batman or Star Wars machines.
The weird thing is that the feature matrix for all the Spike-2 games lists the "CPU mounted line-out audio connector for external amplification" and the manual states that there SHOULD be a CN27 for this but its not there. I called Chas at Stern about this when Star Wars came out and he said he thinks that the manuals and feature matrix info are all wrong and that the line-out feature was cost-removed for Spike-2... yet they still list the line out connector on all new Spike-2 games.
Can anyone confirm if they have a line out on their Spike-2 CPU boards? Or another way to get Line out without buying headphone upgrades would be good too...
Thanks!

I'm using the speaker clips now as well but getting strange audio feedback when connecting two games to one sub. I'm looking to connect 4+ games to each sub and need line out...
I feel like Stern owes us all headphone adapter kits due to false advertising...