This is a simple LED driver board intended for use with Bourns PTL sliders. It's based on an LM317 voltage regulator, two preset range resistors, and a trim pot allowing for brightness adjustment. The resistors can be swapped out depending on the color of the LEDs.
Please note this is a DIY type product and requires basic synth tech knowledge and skills to install. The LM317 TO-220 package is rated at 1.5A, and 150°C. It can power a synth worth of sliders at a reasonable brightness without generating excessive heat.
Note that the driver board trim is ranged for several different LED colors and hence loads....and with some LED's the brightness can be adjusted to a level where high current leads to high heat. Use some discretion...or skip discretion and use a heat sink!