A thought about powering active pickups

[MikeH]

I put an EMG in a guitar of mine, which sounds great, but the guitar doesn't have a back plate so to change the battery I need to take off the pick gaurd.  Huge pain.  And almost impossible to do quickly in a time crunch.  So I was thinking of making a long power cable to run off of my daisy chain and bundling it together with my guitar cable and installing a 9V jack on my guitar.  Which would work, but then I had another idea.  Why couldn't I get a stereo cable and use the center lug for 9V power?  Install a stereo jack, run the 9V lead to the center lug, the ground for the signal and the power are the same, splice the other end of the cable into a mono jack and a 9v power jack and there you go.  I'm sure there must be some problems with this setup.  Seems like I might be risking some noise issues.  Anyone try anything like this?

[aron]

I think you can do this. The only drawback is the specialized cable.

[slacker]

That should be fine, that's basically how those Tillman in cable premaps work. Like Aron pointed out, I suppose the only risk is that if the cable breaks you're in trouble, unless there's some way of keeping the battery as well, then you could just grab a normal cable in an emergency.

[Phorhas]

You could build a "Phatom" power box and which delivers power via the "ring" connection of a TRS input. The "tip" is goind to the pickups and ground is connected to the "sleeve". add  "Through" input and output jacks to the box. This way the power box lets the signal through and supplying your guitar with power, from the pedal board.

[kwijibo]

This is how the Line6 Variax guitars work. They come with a stompbox-sized power supply that uses a stereo cable.

[Processaurus]

If your power supply is regulated it won't cause noise by running next to your signal, plus in any case your signal is low impedance because it is coming from the active electronics.  It's no big deal carrying a backup trs cord with you.  The only concern would be if someone who didn't know the deal plugged a ts cable into the phantom power box, it would short the power supply.