Slide a stud finder across the wall in the general area where you would like to install the wall shelf for your turntable. Mark the location of the two nearest studs that are between 16 and 24 inches apart with a pencil.
Center a shelf bracket over each of the marked studs at the approximate height desired for the shelf. Have someone place a level across the top of the brackets. Adjust the brackets so that they are level. Mark the mounting holes in the brackets on the wall with a pencil. Set the level and brackets aside.
Position each bracket in place against the wall, one at a time. Drive the screws that were included with the brackets through the mounting holes into the wall studs with a screw gun.
Place the hardwood board flat on a work surface. Rout the outside edges of both sides of the board in a counterclockwise direction using a router equipped with a round-over bit.
Sand the routed edges with a fine-grit sanding pad in the same direction as the wood grain until they are completely smooth. Wipe off the sanding dust with a tack cloth.
Spray two even coats of lacquer onto the hardwood board, allowing the first coat to dry at least four hours. Allow the second coat to dry at least 24 hours before continuing with the project.
Center the hardwood board over the shelf brackets. Drive the screws included with the brackets through the mounting holes in the brackets into the bottom side of the hardwood board using a screw gun.