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Two Questions: LEDs and Preamp/pot wiring

Discussion in 'Luthier's Corner' started by Cerb, Nov 25, 2004.

  1. Cerb


    Sep 27, 2004
    Yet another few questions before I start building my first bass.

    - What is the best way to go about installing LEDs under the fingerboard? I figured a simple route (sp?) down the bass side of the neck would do well since I am only wanting the topside markers to be lit. The only problem I see with this would be the possibility of neck warpage. Also, what type of wiring would this require. Obviously I'm going to be putting a toggle switch on it. Would they need to be powered by battery or would the current from the amp do it? If someone could go into detail about this or suggest a site I would be extremely grateful.

    - I'm absolutely lost when it comes to wiring. I've read books as well as the threads here for hours trying to understand how it all works without much luck. Could anyone suggest a site that would cover this stuff in great detail? Another option would be using something like this (Bartolini 3 band EQ/Preamp Prewired Harness):[​IMG] . The only problem I have with that is the location of the output. Is that only a temporary card that it is mounted on, and if it is not could the output easilly be moved to a different location?

    Thanks in advance. :cool:
  2. Bassic83


    Jul 26, 2004
    Texas, USSA
    Go with the pre-wired harness, the board it's attached to in the pic is just holding the components. If need be, you can unsolder the leads to the output jack and install longer ones, though the ones in the pic look long enough to get to a side-mount jack. Might have to replace the jack itself if it is side-mount, depending on how yours is set up, some basses use a long, tube-shaped jack that screws into the side, with the capture nut inside the control cavity. Either way, it's only two wires, just do one at a time and you can't get lost. Happy modding!

    Edit- I just realized I made a mistake- the jack is a stereo jack to turn on the circuit when you plug in the cord, so it's three wires. No biggie, just thought I'd mention it.
  3. Cerb


    Sep 27, 2004
    Hehe. I wish it were as easy as modding. I'm building the whole of it. Should be quite the learning experience though.
  4. Cerb


    Sep 27, 2004
    LEDs anyone?
  5. RyanHelms


    Sep 20, 2003
    Cleveland, OH
    I've heard of active basses being powered by the amp through a stereo cable, but that's assuming an amp that's set up to supply DC from it's input jack. Anyone else know what amps may do this, or is it a mod? Typically, you'ld power your instrument's LEDs or preamp with a battery, since there's no DC voltage being sent to it. (catastrophic amp failure not withstanding....)

    edit- a guitar amp I own has DC present at it's footswitch jack
  6. Cerb


    Sep 27, 2004
    I actually was wondering whether or not the amp had an outgoing current. I'm a bit new to this all. I figured I would have to use a battery for the LEDS and I knew I would need one for the Preamp. Now the only question is what would be the best way to wire them. The LEDS, that is.
  7. FBB Custom

    FBB Custom TalkBass Pro Commercial User

    Jan 26, 2002
    Owner: FBB Bass Works
    Search on the web for something like "wiring LEDs". Read a description because it will be useful in deciding how you wire up your LEDs. Wiring up a string of LEDs is not hard and if you don't understand it, it's going to make the whole job a lot harder. You should at least understand what resistors do, and the difference between parallel and series wiring does. If you don't, you risk burning out the LEDs while the bass is in service. You do not want to do this.

    Now, are you trying to add LEDs to an existing neck? There's a company called "Sims" that does this, but I'd say most basses either have a fiber optic or LED setup built in during construction. Trying to retrofit is going to be risky business and I would think has a high probability in ending in defeat. How are you going to get the LEDs to the center of the fretboard at a consistent depth?

    Assuming you've got the internal structure of your neck worked out....

    You can use the same battery that you use for your preamp. The preamp draws current, but does not "output" current per se. This will obviously shorten the battery life if you do it this way.

    Go with a prewired harness. Again, it helps to understand diagrams so you know where the different signals are going in case you wire it up and get... no sound (it happens, you need to be able to diagnose it since 99.9% of the time it's a problem with installation). But the prewired harness will limit your need for that stuff. You will need to solder the pickups into a blend pot for the Bartolini prewired, and as someone said, it is pictured mounted on a piece of cardboard for convenience.

    Phantom power (getting a DC power source from your output cable) is not recommended, since most bass amps will not be able to supply phantom power.