Not experienced in reading schematics - Need your help please!

[IrishLuck]

Hey everyone,
I came here to gain some knowledge about wiring an acoustic guitar's preamp. It is missing the wires that go between the 1/4" TRS output jack and the preamp. The battery wiring to the preamp is good, and so is the wiring from the pickups to the preamp. I just need to figure out how to wire the 3 wires that go to the TRS output jack. I have a schematic from Yamaha. (It's the system 34 in the schematic) Unfortunately he was unable to tell me which wire goes where, so he sent me the schmatic and I can't figure it out. I have zero experience with them. I circled in red the output jack on the preamp that has three pins that connect to wiring to the TRS output jack. I just need to know what it means and what each pin is for (I assume it's for power, ground, and hot) but don't know which pin is which and also where they need to be soldered to on the TRS jack. I have some soldering experience, but I want to be sure to connect the right wires to the jack and preamp before soldering them.
So if anyone can make heads or tails of the three pin female jack on the preamp and let me know what each one is and where it should be soldered to on the jack that would be GREAT!!
Any help or advice is much appreciated!!!

[The Dude]

The jack shown in the schematic is actually a switching jack and not TRS, but you can achieve a similar thing with a TRS jack.

Pin 1 is ground or sleeve of the jack.
Pin 3 is battery negative and either ring or switch (depending on your jack).
Pin 2 is signal out or tip of the jack.

The battery negative connects to ground via the jack to prevent it from drawing current when the guitar is unplugged. You can achieve this with a switching jack or a TRS jack. When you insert a mono plug into the TRS jack the sleeve and ring are shorted together via the plug connecting battery negative to ground and powering the circuit.

[IrishLuck]

Great! That was quick and informative!
I sure appreciate it.
It had a TRS stereo jack in it but was broken. When I pulled it out it had the 3 wires soldered to it. The bare wire went to the long center post and the red and white wires were wired to the other 2 small posts, But since the wires were clipped off, I have no idea what order they went into the preamp. I noticed in the schematic the pins are labeled 1-3-2 instead of 1-2-3. This is what confused the tech at Yamaha. So when you refer to pin 1, 2 and 3 are you going by the way they are labeled in the schematic, or going from left to right?
Thank you so very much, I want to do this right. Any damage possible if it's wired incorrectly? Or will it either just have no sound or drain the battery? I wouldn't want to damage anything.
Thanks again!!!

[The Dude]

The numbers are too fuzzy to read on my PC, so I may have them wrong. You can follow the connections. Look at the jack connections. One goes to ground, one goes to battery negative, and one is the output (coming from IC 2 through a cap and resistor).

Edit: Ok,......I just saved the picture so I could zoom in. I did have the numbers wrong and corrected my original post. It should now read to match the schematic you posted.

[Dave H]

Is that battery symbol reversed? They have the +ve (long side) of it connected to ground.

[The Dude]

Missed that. Nice catch Dave H.