The downside of a voltage regulator, is if the part failed for any reason the full voltage will be applied to your device. Creating much damage or fire if the difference is more than a few volts.
I had a go with a few lm317t regulator and a large volt supply, I'm happy to say only one test light bulb was damaged on the device side but 6 out of 6 lm317t went up in flames on my prototype board. It's not too damaged just cosmetic, some plastic melted down and blacked.
I found that a lm7805 makes a more robust variable Power supply. Place a 470 ohm between the output and ground, than a 10 k pot between gnd. On regulator and ground. Very simple and effective.
