I wasn't so much thinking of adapting the Line 6 box as adapting the socket/system at the guitar end. The box results in a TRS cable with signal (in) on tip, 9vDC on ring and earth on sleeve.
I haven't really followed what is happening at the guitar end though. I just thought that a robust pre-made (as opposed to home-made) solution for delivering 9v to a guitar might be an option - but appreciate that it may not
Ah right, got you. For some reason I'd got it into my head that the line6 box wasn't kicking out at 9v. I don't know why I thought that. I didn't measure mine when I was fiddling around with things a while ago. Given that it will also run from a 9v battery that would make it a logical assumption.
I've not slept a lot recently, probably best to regard all of my comments with even more disdain than usual...
Yes, it's normally possible, though not all pre-amps use 9v or use a 9v PP3, (where it's generally easy to provide a shorting clip for the battery connections), and on some where they use a jack socket with an independent switch for the battery, then it may not work.
But it should be possible to get at least 90% of electro-acoustic pre-amps remotely powered.
Bought 3 batts (still found nothing for SWMBO!) and they come apart very easily, knife blade and the top pings off bish-bosh. Big blue cell reads 1.7V off load after 1/2 hour on charge and there is a sub postage stamp PCB with USB ports and an MP3401A SM chip and inductor on it. Some form of "swinging choke chopper" converter.
Red and black wires from cell to PCB are ~25mm and could easily be extended.
I have found sites that PROMISE a .pdf of the chip but none so far deliver (Brexit FX) but I bet better eyes and steadier hands than mine could kludge the feedback circuit to get 10volts?
I have modified a pedal converter that normally produces 300V to give 48V of very stable and clean phantom power from 20V DC.
