Or if you have 6 VAC/6 VDC get the white LEDs that match the base. They are more expensive, but draw less juice, put out less heat and last forever. I have been converting all of mine over and it has solved the age old, where did I leave that pack of bulbs question.
Also for boxes that have been convered to run a switcher, I can use the -5 V (which most games to bother with) or +5 V without having to worry about drawing too much power and tripping the current limiter.
They also make 12 V LED sets, but I don't know where to get them. There is a thread or two in the pinball machines forum that discuss the LEDs, where to get them and which ones are best.
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