[sdiy] MIDI phantom power...over 5 pin MIDI connector ?

[rsdio at audiobanshee.com]

Sorry to reply twice, but I didn't notice you want to use only 2 MIDI pins, not 3. Please note that MIDI Solutions is using 3 MIDI pins, 2, 4 & 5. The only pins that remain unused by MIDI Solutions are the two pins, 1 & 3.

If you truly want to use only 2 MIDI pins, then you have a special kind of electronics magic to perform. You have no ground reference when using only 2 pins. When MIDI data is not transmitting, there is 0 V potential between the 2 pins. You'd have to create a virtual ground with your charge pump, and make it negative relative to the 2 MIDI pins. Then, for MIDI output, you'd need to generate a current loop without any solid ground. I want to say it's impossible, but it may only be true that it's very hard.

What's wrong with a battery or a wall wart?

Brian Willoughby
Sound Consulting


On Sep 9, 2015, at 5:13 PM, jpdesroc <jpdesroc at oricom.ca> wrote:
> Does anybody have schematics of an easy way to send
> power using the 2 MIDI pins in a 5 pins cable ?
> I don't want to use any of the 3 remaining wires of the cable
> for universal use on ANY MIDI cables..
> I know this company uses that technology:
> 
> http://www.midisolutions.com/prodmrg.htm
> 
> but I can't find any circuit ideas that uses it..
> I know I'll need some kind of charge pump design to get something like 5 volts
> out of the MIDI (idle or in use) signal.
> 
> Any clues ?
> 
> JP