Thanks everyone for the kind words. This was my first full-on retheme. I had converted a Heavy Metal Meltdown into an AC/DC pin ( before AC/DC came out ) but I did not completely redo the playfield nor the sound on that one.

The project took at least twice as long as I expected, mostly due to the difficulty I had with the sounds. I was initially hopeful that I would be able to use the existing switches for the sounds, but as I started to experiment with it, I soon discoered that the switch matrix and the fact that many switches had capacitors made it impossible.

Although there are ways to tie the sounds into the existing soundboard, my electronics background is minimal. Plus, I felt that the original circuitry would not complement the sound bites I had in mind.

The sounds come from two mp3 trigger boards purchased from Sparkfun Electronics. One board runs the switch sounds and the other is for the background sounds. Although the video didn't show it, there is a lighted green button on the front that lets you scroll through 5 different background songs or turn off the background sound altogether. Of course the beauty of it is that you could just pop out the micro SD chip and put your own favourite mp3s on it and have these songs playing in the background.

From the beginning, I wanted to see how cheaply / easily I could do this retheme. In keeping with this, I just used two pairs of powered computer speakers ( relatively inexpensive ones ) installed in the cab. Seems a little piecemeal, but it was the best compromise for me, rather than trying to figure out how to tap into the soundboard amp and hardwire speakers into the cab.

The whole thing was very much a learning exercise for me. At this point, I just want to get it out the door and start working on the next one.