Fæpbœx III: 3-Band Preamp

Discussion in 'Effects [BG]' started by EricssonB, Jul 21, 2012.


  1. EricssonB

    EricssonB Supporting Member

    Apr 5, 2011
    CoSpgs, CO.
    Made a rip-off of somebody else's ripoff of a Stingray 3-band preamp. Didn't like the guy's layout, so I made mine with a clockwise rotation on the signal flow. Yes, you may notice that the digital layout is slightly smaller than the one in the picture -- I didn't realise how large those components were in real life. Just started from the input and stretched it out just a smidge.

    Works great, thanks to some help. I had added a fourth capacitor instead of a straight shot between -V and ground. Don't do that. Fixed on schematic.

    Next build of it will be on a smaller board and be placed inside of a 1590 enclosure.

    [​IMG]
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    [​IMG]
    (Heh, picture from before I scrapped that fourth capacitor. Bias power is yellow wire, ground is white; +/-V is wired from one side to the other on the underside.)
    [​IMG]
    Built two on the same board, to be split and put into the final Bœxes, one sent to a friend. How romantic.
     
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  3. EricssonB

    EricssonB Supporting Member

    Apr 5, 2011
    CoSpgs, CO.
    Suggestions on layout? Feel free. Not asking for a lot beyond an eye to notice something that I didn't.

    About ready to build these things, finally. Figured I'd be a perfectionist and draft up some lines for when I take it to the drill press. To be printed and used for drill press guides on a 1590 enclosure. Most of the lines are merely for reference.

    God forbid somebody accuse me of not putting in enough LEDs.

    Why yes, I am drafting this up using Adobe Illustrator, everything being done according to a grid and using centimeters for precision. Measured up all the components by hand, beforehand.

    [​IMG]
    [​IMG]
    Worked just fine for my guitar that I built a few years back.
    [​IMG]
     
  4. father of fires

    father of fires Commercial User

    Nov 29, 2006
    BALTIMORE CITY
    Chief of Medicine at Damnation Audio
    Looks fun. Your input stage is quite confusing???!!!

    Where do you come up with the design? It looks like a lot of components for a basic buffer? Is this going to be used with an active or passive bass?

    OH I see! Its the Sting Ray schematic. Sorry. I wasn't paying attention.

    As it stands, it looks like it would sound the best with a passive instrument without any buffers (tamer highs). I'd love to hear sound samples.
     
  5. EricssonB

    EricssonB Supporting Member

    Apr 5, 2011
    CoSpgs, CO.
    You can find sound samples under the "somebody else's ripoff" link on the original post.

    I'm building it in an enclosure because I have four instruments and they're all passive. :)
     
  6. EricssonB

    EricssonB Supporting Member

    Apr 5, 2011
    CoSpgs, CO.
    Guess it could use an update and closeout. Finish up the original Fæpbœx series. Made a "I" last week because I had some parts laying around; LPB-1. Why not.

    [​IMG]
    [​IMG]
     
  7. Roscoe East

    Roscoe East

    Aug 22, 2011
    Is that pronounced "fap-box"?
     
    RedJag likes this.
  8. EricssonB

    EricssonB Supporting Member

    Apr 5, 2011
    CoSpgs, CO.
    I think so. :ninja:
     
  9. Javier Stella

    Javier Stella

    Aug 29, 2016
    EricssonB Hello, I need help !!! please ... I built twice the preamplifier and does not work, it seems to have no gain. You feed it with a 9V battery or two? I'm testing the pre with a Yamaha RBX375 bass. Thanks for your help!!!
     
  10. Javier Stella

    Javier Stella

    Aug 29, 2016
    When I turn on the preamplifier, background noise is heard as if working. I turn pots and note that it works the tone control and volume, but seems to have no input signal. I tried with passive mics bass and also I have connected a cell, but does not work.
     
    theunknowndude likes this.
  11. EricssonB

    EricssonB Supporting Member

    Apr 5, 2011
    CoSpgs, CO.
    Sorry to hear you're having problems with it. (I can't believe it was four years ago I built this thing; time flies.)
    -- I actually made it in pedal form and generally run it with a 12v adapter. The IC is rated for 15v (if I remember correctly) so two 9v batteries might fry it. Just use one.
    -- I think I may have had a similar problem and it had to do with the input-side of the IC not getting power (the RED connection between G2 and A14). Definitely double check how the power is going through it. That's where I'd start.

    Do you have extra ICs? I know I ruined a good few of them trying to get this to work. Maybe replace those if you haven't already.
     
  12. Javier Stella

    Javier Stella

    Aug 29, 2016
    Hello! thanks for answering. If, lol, I have tried several ICs, ok I will try what you've told me !! See you later!!
     
  13. boomertech

    boomertech Frank Appleton Gold Supporting Member Commercial User

    Apr 8, 2009
    Syracuse, NY
    Designer/Owner of FEA Labs
    The TL072, TL062 and TL082 are 36V opamps. So, you can do split rail + and - 18V or single ended 36V.

    -Frank
     
  14. Javier Stella

    Javier Stella

    Aug 29, 2016
    Hi Frank!! Yes, but I'll place the preamp in cabide low, so I want to use a 9V battery ...
     
  15. Javier Stella

    Javier Stella

    Aug 29, 2016
    Sorry, I meant "cavity bass". My english is very bad....
     
  16. boomertech

    boomertech Frank Appleton Gold Supporting Member Commercial User

    Apr 8, 2009
    Syracuse, NY
    Designer/Owner of FEA Labs
    You were asking about using 2 9V batteries for 18V. 18V is very safe for these opamps.

    -Frank
     
  17. Javier Stella

    Javier Stella

    Aug 29, 2016
    Yes, I understand Frank, sorry, thanks!!