"activating" an OLP MM2 bass

Discussion in 'Pickups & Electronics [BG]' started by av500, Dec 15, 2014.

  1. av500


    Apr 2, 2014
    I have a first series OLP MM2, the one with the passive treble and bass control. when I bought it, all three potentiometer axes were broken off and instead of getting new pots for this passive setup I decided to make it active.

    The circuit is the original Stingray 2-band EQ. I did not want to route a hole for a 9V block battery holder, so the tiny 9V battery will do. I made a battery holder from a cut down AAA holder and a 3D printed frame to hold it together. The stingray EQ asks for a 1M reverse log pot for treble, I just put a 1M linear instead.

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    Crater likes this.
  2. Brilliant!
  3. bassbenj


    Aug 11, 2009
    VERY NICE JOB! Yeah I've got to do the same to my OLP. I've got the "Uncle Fluffy" circuit board here ready to go. I believe that is the same circuit you've wired. The original OLP passive circuit was REALLY bad! I've re-wired mine with a new passive circuit that is much better but the whole idea of a Stingray is the active preamp, but not just any preamp, but the special boost available from originals (or the expensive John East version which is the "ultimate"). I really like the smaller battery idea. I'm going to have to steal that one for mine! The deal is I really don't need a battery holder because I power most of my basses with "phantom" power from the amps over a TRS cable. However, I still like to leave the battery holder in there (you short the battery clip with a special clip to make the phantom power thing work), but in the case of the OLP I can put the smaller holder in there strictly for emergences should the phantom power fail. And you should be aware that the original Stingray circuit that we have uses VERY little current so a smaller battery is more than enough!
  4. av500


    Apr 2, 2014
    THANKS, and yes I know the circuit uses very little current, that's why I concidered using the tiny battery