What are the power requirements of the MasterMind?

The MasterMind requires 9-12V, AC or DC, with 200mA minimum current capacity. The connector is a standard BOSS-type, 5.5mm x 2.1mm x 9.5mm

The MasterMind will accept phantom power over pins 6 and 7 of a 7-pin MIDI MIDI cable. You can always use a 5-pin MIDI cable to connect the MasterMind (it fits in a 7-pin jack), but you will need to provide power to the MasterMind using an AC adapter. Note: some devices will pass phantom power over pins 1 and 3 - don't use them with a MasterMind! It won't work and can possibly damage the MasterMind.

Can I chain MasterMinds together?

Yes, you can chain two MasterMinds together, or even three or more! Just connect the Remote In to the Output of the next MasterMind in the chain. The MasterMind that doesn't have another MasterMind connected to its Output is then connected to the rest of your gear. The Remote mode needs to be turned on on each MasterMind (please refer to the manual).

Once everything is set up, pressing a button on a MasterMind will cause all MasterMinds in the chain to respond.

In later MasterMinds, (serial MM10200 and up), the Remote In jack of each MasterMind is a 7-pin jack. You can chain phantom power from one MasterMind to another using 7-pin MIDI cables. Up to three MasterMinds can be chained in this way. Beyond that, the MasterMinds should be powered with an AC adapter. Older MasterMinds can be upgraded by RJM to have this phantom power chaining ability as well.

Can I use a momentary switch attached to the Exp Pedal jack as an additional switch, to send CC messages, or for tap tempo?

Yes, although you'll need a specially modified footswitch to do it. A diagram of the modification is attached.

Which expression pedals are known to work with the MasterMind?

All volume pedals will work (if you follow the connection diagram in the MasterMind manual). These expression pedals (and volume pedals that have an expression output) are known to work:

Rocktron Hex
Korg XVP-10

These are known to not work 100% correctly (although they can be modified to work by swapping the tip and ring conductors):

Roland EV-5
BOSS FV-500

This is obviously an incomplete list. If you have any results to share, please let us know!