Since I'm going to use this board in a Data East machine I removed the extra power components for the WPC.
Even though the original Data East power for the sound boards are known to be noisy I would like to try and make this work without adding a dedicated power supply in the cabinet.
Removing the extra WPC power components helped. I installed an LM2577 based DC/DC convertor where the old LM2596 one was and then just had to sever one trace on the 12V in at the Data East power and route that to the fuse. The other side of the fuse goes to the input of the DC/DC convertor so that can help clean up the DC 12V power. There a a lot of people adding these inline to help reduce noise on the original DE sound boards. It seems to have helped a lot the crackling I heard when the flash lamps go off is no longer there. Most of the sounds are really good.
I still have a bit of crackling on some sounds and not sure if it is on the sound board or with the sound set files. Need to do some more testing and may plug in an external supply temporarily for testing. I am also using the remote volume control in case that makes a difference.
Just wanted to share this power mod for anyone else running this board in a Data East to see if it helps improve sound quality.
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