Quoted from docquest:
When i had the pinsound board in my DE Trek I was using the stock power supply and it worked fine. Right now, I have the pinsound board in my Diner. When I get home tonight I'll put the pinsound back in Trek and see what the 12v line is running at. I'll also measure the 12v with the stock supply.
With my stock DE power supply and stock DE sound board I measuring in the range of about 10.3v - 10.7v on the 12v line. When I put the pinsound board in it measured slightly higher, more in the range of 10.5v to 10.9v. In both cases, I played the game during measurements to see how much it would move around.
As a point of comparison the same pinsound board in my Diner with an xpin power supply measures a very steady 10.6 - 10.65 volts. With the stock power supply in my Diner the 12v line measures 10.0 to 10.5 volts and the pinsound board doesn't seem to initialize and stays quiet. Even though the stock DE power supply ran low for 12v, the stock sound board worked fine. I had to upgrade to the xpin power supply when the pinsound board was added.