The EXP-DOUBLER is a unique product from PIRATE MIDI that allows you to use 4 expression pedals with a single BRIDGE6 or BRIDGE4 controller.
A Flexiport, when in "Exp-Doubler In" mode can read two separate expression pedals, while not taking up any more Flexiports than a single expression pedal would.
Before plugging anything in, please make sure your chosen Flexiport (or both Flexiports) are set to "Exp-Doubler In" mode. Plugging devices into Flexiports when they are not in the correct mode may cause damage and void your warranty.
First, you will need to power your expression doubler with a centre-negative 9v DC cable. Like most guitar pedals and power supplies, we use 2.1mm centre-negative barrel jacks.
After you've provided power, connect a cable from a Flexiport, to the EXP-DOUBLER "Flexi1" or "Flexi2" jacks. You will likely need a cable adapter because the EXP-DOUBLER has 3.5mm TRS jacks, but Flexiports are 6.25mm (1/4") TRS. Three adapters are included with your EXP-DOUBLER, and more are available at piratemidi.com/shop or cables are available in other online stores.
Of course you can also use any 3.5mm to 6.35mm (1/4") TRS cable you may own.
Now you can connect your expression pedals directly to your expression doubler - using cable adapters as needed. "EXP 1A" and "EXP 1B" will connect to the "FLEXI1" port on the EXP-DOUBLER, and "EXP 2A" and "EXP 2B" will connect to "FLEXI2" port. Once you have plugged in your expression pedals, you will be able to assign MIDI commands to each expression pedal on your MIDI controller.