Acoustic Preamp/Transducer Wiring?

Discussion in 'Pickups & Electronics [BG]' started by rdubgt, Jul 11, 2013.

  1. rdubgt


    Mar 11, 2013
    I recently bought a used acoustic. Body/construction was excellent but the seller did inform me that the pickup wasn't working. He said he had pulled the battery out once- he thought it was just a loose contact. He took it to a tech but said it went from "working some of the time" to "never working" after the tech...

    I opened it up last night and found the preamp's outputs desoldered and hanging in the body. The transducer was wired directly to the output jack- never getting to the preamp!

    I can't find any kind of general diagrams, but on the preamp board I have 5 terminals: 2 (black/red) for the 9V and 3 (red, white, black) which I assume are for the Tip/Ring/Sleeve of the output jack. There are no holes for transducer inputs but there are two large solder pads on the back with nothing attached.

    Anyone have an idea on how to properly wire this guy? So far I tried soldering the 9V wires to the preamp, putting the xducer leads on those 2 big pads, then wiring the 3 preamp
    outputs to the TRS. I'm getting a very faint signal hidden in tons of noise, and 9VDC on my output... Not so good! Also, when maxing out the volume pot I get some squealing... Any ideas? Could the preamp just be fried?

  2. It's odd that the negative terminal of the battery would connect to the preamp, and not the jack. There is no purpose for such a connection, so it is likely that two of the wires will be electrically continuous.
    Do you have an Ohm meter?
  3. rdubgt


    Mar 11, 2013
    Yes - I do.