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Onboard preamp schematics

Discussion in 'Pickups & Electronics [BG]' started by KosciaK, Dec 15, 2003.

  1. KosciaK


    Nov 3, 2003

    I'm working on an fretless conversion and decided to make a new electronics too. I'm looking for schematics for some onboard preamp (like with active pickups). Or maybe a page whre I can find some useful informations.

    Thanks in advance for any help!

    Best Greetings!
  2. Here's a link to the Guitar effects oriented web site

    There might be some help there.

    Here's a three band circuit. You could play with the values a little to get better bass tailored response.

    3-band control

    And another with lots of cool looking stuff.

    discover circuits

    I'm going to have to spend some time checking this out.

    Hope this helps

  3. pjbasser


    Sep 26, 2003
    What do u need?

    I can always draw one up for u, especially if u don´t mind using ic:s...

  4. nonsqtr

    nonsqtr The emperor has no clothes!

    Aug 29, 2003
    Burbank CA USA
    Hi KosciaK, if you ping me by e-mail, I can send you a scan of one I recently developed. It's a "front end" that goes in front of the tone controls of your choice. It's a true DIAP (differential input active preamp), and it completely isolates the pickups from ground. Guaranteed to eliminate 99.99% of all the hum and noise problems in your instrument. Kind of pointless putting in an active preamp if you're still grounding one side of the pickup, right? The other thing is, have you decided what frequencies you're looking for, for the tone controls? And have you decided what "kind" of filters you want to use (shelving filters, bandpass filters, or ???)?
  5. pjbasser


    Sep 26, 2003
    This I would really like to know how it could work...
    Well that the signal gets amplified/impedance matched is one thing but...

    To get a differential inputstage to work properly it must have 2 different phases from the pickup..

    (since the idea of a diff.amp is to only amplify differences between these signals and therefore no hum can get in )

    So I would like to know how u solve that?

    VERY curious....

  6. ejsagun


    Jan 20, 2003
    hey nonsqtr

    im interested in this front end circuit of yours. can i get a copy? then maybe we coulc share some ideas