Loops 7 through 10 on the Mastermind PBC are stereo capable. When the Mono/Stereo switch is in the "out" position, the Mastermind PBC takes the signal coming into loop 7 and sends it to both the left and right sides of the stereo signal, creating a false stereo signal. In the "in" position, it leaves the signal from loop 7's input unchanged, allowing you to send a stereo signal into Inputs 7-10.

The Mastermind PBC's two outputs are extremely flexible. When the Mono Output switch is in the "in" position, it takes the left side signal and feeds it to both the A and B outputs, allowing you to use the outputs as a mono A/B/Y switch for switching between two amps. In the "out" position, the A and B outputs are fed from the left and right sides of the signal, respectively, for stereo operation. The Mastermind PBC also features an isolation transformer, which can help alleviate ground loop hum when using two amplifiers. You can also invert the phase of Out B, in case your amps don't sound right when played together.

If you've got MIDI-controllable pedals, like those made by Eventide and Line 6, the Mastermind PBC has got you covered. 

Thanks to the RJM Music Mastermind PBC's internal line mixer, loops 7-10 can be routed in parallel. This means that the effects don't affect each other, so you can pile them on without muddying up your tone. Parallel routing can also help you avoid AD/DA degradation by mixing a dry signal in with your processed signal. On top of that, the line mixer also allows delay and reverb tails to trail off naturally, without echoing any new notes played. You also get a "kill dry" function that allows you to output only a wet signal, so you can use the output level controls on your pedals to set the amount of effect you want.

The RJM Music Mastermind PBC utilises a series of buffers to "strengthen" your guitar's signal and preserve its sound quality. And in the event that you'd like to turn the buffers off (pedals such as Wahs and germanium fuzzes work better without a buffer), all are independently switchable.

The Click Stopper circuit eliminates those annoying clicks by briefly muting audio output when the relays are switching.

• 10 audio loops, four of which are stereo capable and series/parallel switchable
• Outputs can be configured as a stereo pair or as A/B outputs for switching between two amps
• Out B has a switchable isolation transformer and a phase switch
• Audio buffers keep your signal clean
• Click Stopper noise reduction circuit for transparent switching
• 4 function switches for controller amplifier channels
• Internal line mixer for running effects in parallel
• A full-featured MIDI controller that can send any type of MIDI message
• Expression pedal input that can be programmed to generate MIDI messages
• Easy-to-read LCD display displays preset, song names, and more
• USB host port for backing up and restoring settings to a USB thumb drive
• External switch input allows two more switches to be added
• Mac/PC editor software allows for faster and more comprehensive editing
• Includes an integrated tuner
• Power adapter not included