Adding Volume Remote control - how to get 9V?

I built the Korg preamp in my own chassis and wanted to add remote volume control to it.
I saw the Alps version from Bent Audio and wanted to incorporate it, but want to know the best way to get 9V DC to power the device.

I currently have a CapMX power supply and adjusted the voltage to 24V to run the Korg. The website for the Bent Audio device says between 8 and 24V dc but then the manual states 8 to 18V. Regardless, I would like to know the best way to get 9V off of my power supply?

http://www.bentaudio.com/index2.html
5C1182AC-55F2-43AF-9ED7-284B990593B7.jpeg
 
The board appears to have a 3-pin regulator on it; most likely 5V. An LM7805 can handle 24V, but the caps probably aren't rated high enough, hence the lower recommended limit for the board. I think a simple 15V 2W zener and resistor to limit the current to around 50-100mA would work fine. The manual says it only draws around 25mA when the motor is powered.