Electric lap steel guitars are basically a piece of wood with a hot pickup on them. They are played with a steel bar rather than fretted. Inexpensive lap steel guitars, such as the Rondo SX, can be upgraded by replacing the pickups and hardware. A hot vintage pickup, such as a Supro, will make a world of difference to the tone and sound of the guitar.
Purchase a Supro single coil pickup for the guitar. Replacing the SX pickup with a Supro pickup will help you to get a vintage lap steel guitar sound.
Remove the bridge and nut with a Phillips head screwdriver. The nut and pickups are secured to the guitar with two screws.
Remove the control panel cover on the back of the guitar. This gives you access to the volume and tone pots and the input jack.
Unscrew the screws holding the pickup in place. Lay a soft cloth or towel on the guitar to protect the guitar finish. Gently lift the pickup out of the pickup cavity and lay it on top of the cloth. Remove the positive (white) and negative (black) wires connected to the pickup with a soldering iron.
Place the new telecaster-style bridge in place on the guitar. Mark the holes for each of the six strings with a pencil. Remove the bridge. Drill the holes for the strings with a hand-held electric drill or a drill press (a drill press is more accurate). Set the bridge back on the guitar. Insert and tighten the mounting screws.
Place the nut in the neck slot. Secure it in place with two screws.
Connect the positive and negative wires to the Supro pickup with a soldering iron. Place the pickup in the pickup cavity. Insert and tighten the mounting screws. Put the control panel back in place on the rear of the guitar.
The standard nut on a guitar is 1 by 5/8 inches, and the standard bridge is 2 by 1/16 inches. Adding a slightly larger bridge and nut provides more space between the strings. This makes it easier to stay in tune while you are slanting the bar. Search for a lap steel bridge that measures 1 by 31/32 inches and a nut that measures 2 by 3/16 inches. Consider buying a Telecaster-style bridge. The strings are mounted through the rear of the guitar, and this adds a little more resonance and tone. Rondomusic.com provides a wiring diagram for the SX lap steel guitar.