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J-Retro Drain

Discussion in 'Pickups & Electronics [BG]' started by jrex, Jun 27, 2005.

  1. jrex


    Jun 17, 2005
    SouthEastern Wi.
    I purchased a used, ebay, j-retro pre-amp for my jazz bass. I love the sound for the two days it lasts. It seems to drain the battery about every couple of days. I'm not playing it every day so when I do pick it up and plug in, it's dead, very unreliable.
    What's the solution, anyone had this problem?
  2. There's obviously some wiring issues with your pre. I have an East pre, and I have absolutely no issues with battery drain.
  3. Trevorus


    Oct 18, 2002
    Urbana, IL
    ever leave it plugged in? That'll do it every time. But Halftooth may be right, and you may need to check the wiring.
  4. Get a wiring diagram from the manufacturer and double check it.

    I bet the power isn't cutting off when you unplug the guitar.

    Check the negative from the battery, it should probably not be hooked to the ground of the input jack, but to the switch part of the input jack.

    If you put it in a passive bass so there's only ground and signal on your jack, that's your problem.

  5. Trevorus


    Oct 18, 2002
    Urbana, IL
    Wow, steve, that sounds like a very likely culprit. I didn't think of that right away.

    Anyways, make sure you are using a stereo jack, and that the pin that touches the ring (not the tip, or the ground on the main part of the jack) is the ground of the preamp itself, and the and the ground of the battery is hooked to the ground of the instrument. That way, when the plug is inserted, it connects the ground to the preamp, making the circuit live, and when it unplugs, turns it off.
  6. BassyBill

    BassyBill The smooth moderator... Gold Supporting Member

    Mar 12, 2005
    West Midlands UK
    The J-Retro comes with everything including the jack pre-wired. All you do when installing is connect the ground wire to a ground on the bass, such as the wire from under the bridge. If you bought it used, I guess this may have been tampered with, but I don't see why this would be the case.

    The other thing you might check, as the unit can be quite a tight fit when installed in a standard front-routed Jazz, is whether any of the wires are touching onto somewhere they shouldn't because of the lack of space. I suppose it's possible that this could cause a short which keeps the thing powered when you unplug it. Just a thought.
  7. DaveAceofBass

    DaveAceofBass Supporting Member

    Feb 20, 2004
    Charlotte, NC
    I would suggest emailing John East. He's extremely helpful. East preamps are the best!!! www.j-retro.co.uk

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