There are a few ways you can do this...

• Reactor and Mad Planets need +12, -12, +5, -5, and +30VDC (for the audio amp)
• Q*bert needs +12, -12, +5, -5, and +30VDC (for the audio amp and knocker)
• Krull needs +12, -12, +5, -5, and +16VDC (for the audio amp)

As an example, we will convert a Q*Bert to use a switching power supply.

1. There are some switching power (PC style) supplies that have a +24VDC output along with the normal outputs. The +24VDC will work in place of the +30VDC but you will have to adjust your volume controls higher as the audio amp will receive less voltage and thus, output less volume. The +24VDC will be more than adequate for the knocker solenoid.

2. Use a normal switcher (PC style) to provide the +12, -12, +5, -5 and then continue to use the 30volt section on the original power supply BUT, replace the +30volt zener diode with a 27volt 5 watt or high Zener diode

3. Use a normal switcher (PC style) to provide the +12, -12, +5, -5 and then use an external audio amp for the sound output. Remove the audio amp IC from the audio board, then run a wire from the audio signal pin to the ‘new’ external audio amp. The only drawback is that the knocker isn't powered and cannot be used. However, there are +12volt solenoids that could replace the +30volt knocker coil.

**Remember to run grounds for the self-test switch, and joystick switches!**

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