FCB1010 phantom power.....literally

[swinginguitar]

I am about to implement the readily available plan for FCB1010 power. Was wondering - I have an unused mic preamp with phantom power in the rack (Eleven Rack)...could I not tap that to power the FCB power box instead of a wall wart?

Any snags? Is there enough current?

I presume I would have to divide or regulate the ~48v down to something like 12v in the power supply box to be sent to the FCB via midi cable....thoughts?

[Seljer]

The phantom power on mic inputs is supplied through two 6800ohm resistors.

If you're not going to be sending audio down that cable, you can just wire the hot and cold wires together and a slap a 12V zener diode on there with a big filter cap and you've got a supply good enough for small circuits. Only caveat is you're limited to less than 10mA because of those resistors.

[swinginguitar]

i'll need more current than that...so never mind

(i also want a 9v tap at the floor for pedal power)

[swinginguitar]

Next question:

If I were to have my interface/power box accept MIDI connectors on one side, but use CAT5 on the other side (to the floor), which if any of the ground pins can use a shared wire? I'll have midi in and out as well as the +12vDC and associated ground reference. Can any of those 3 grounds be shared to conserve pins/wires? Or does each MIDI direction have to have its own dedicate ground?