Micro Cube RX Mods: The Speaker Switch Mod

The Roland micro-Cube RX 5-Watt Wonder

The Roland Micro-Cube RX Amp is a guitarist's dream come true. With awesome tones, full effects, and 3-band EQ, this practice/recording amp rocks. I started using mine live and decided to make some mods especially for Live Applications.

Check out the Mods (so far)

Speaker Switch Mod: this allows the internal speaker to remain ON when the Rec/Line Out jack is being used

Footswitchable Boost and Tuner Mods: the RX's Boost and Tuner functions are ideal for a footswitch mod - very handy on stage
More Mods to Come . . .

Roland, Micro Cube, and Micro Cube RX are trademarks of the Roland Corporation and are used for reference only. This site is not affiliated with the Roland Corporation in any way.

The internal speakers are automatically switched out of the circuit when you plug headphones or a line-out into the Phones/Rec Out jack on the back. For live applications, you might want to have the speakers switchable to remain on and active while you are using the line-out for the PA system. Here's how to do it:

Flip over the top CPU board to expose the jack connectors on the other side. The middle jack is the Phones/Rec Out jack. There are 4 pins in a row that just behind the jack. The 2 right-most pins are the switch pins. Shorting across these pins will turn the speakers back on. Double-click on the picture to zoom in close and see the pair of pins that will require the solder and wiring out to the switch.
Next, solder two wires to these pins. These wires will go out to the SPST switch mounted on the back-plate, so make sure you cut enough wire to reach. This switch controls a soft-mute switch at the preamp. This means that the pins do not carry an audio signal and you can make the wire lengths as long as you wish. Also, you don't need to use shielded cable for the same reason.
Route the two wires around the boards and to the back plate when you are ready to complete the mod (you might want to work on the other mods first - this should be a last-step for both sets of mods). Solder the wires to one side of the SPST switch. Closing the switch will short across these wires, turning the speakers ON. Opening the switch turns the speakers OFF but only if something is plugged into the Phones/Rec Out jack. Note that the turn on/off is not instant, but rather fades in and out - this is the soft-mute switch in action.