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Help mod my boss sd-1

Discussion in 'Effects [BG]' started by kringle77, Jul 17, 2005.

  1. kringle77

    kringle77 Supporting Member

    Jul 30, 2004
    Massena NY
    I want to know which cap values, etc. I need to change to give this pedal more low end. I think that I need to increase the value of C1 but I'm not sure. I will probably do a true-bypass mod later. I love this pedal but it suck low end big time.
  2. Basstyra

    Basstyra Commercial User

    Apr 3, 2005
    CTO @ Two notes Audio Engineering
    You have to increase value of all the coupling caps, which means all the cap that are in serie in the signal path. Make them 10 more bigger for example.

    Or maybe (I don't know this pedal) there is only one or two to change because the others are big enough. Increase the value of the smallest to begin with, maybe.

    Go to the http://www.diystompboxes.com forum for more help ! ;)
  3. kringle77

    kringle77 Supporting Member

    Jul 30, 2004
    Massena NY
    Since there are no parallel caps in the circuit, I'm thinking about changing the first and last cap of the pedal to 10 uf. What do you think guys? The first cap is 0.047uf and the last is 1uf.
  4. bass-shy


    Jan 11, 2005
    That should do the trick nicely. I recently decided to do some mods of my own and have had great success thus far. Good luck and keep pushing the boundaries.
  5. kringle77

    kringle77 Supporting Member

    Jul 30, 2004
    Massena NY
    I am assuming that the input cap is the first one in the ckt. and the output cap is the last? Or, is the input cap the one before the op-amp? I could sure use some more tips. I've been reading through the other threads. I've got some 10 uf caps which I think would work well but I am not sure which way to orient them in the ckt. Which side should the + be on, the side that the bass signal is coming from? Or, should I not use these at all? They are the only large value caps that I have on hand right now.
  6. seanm

    seanm I'd kill for a Nobel Peace Prize! Supporting Member

    Feb 19, 2004
    Ottawa, Canada
    Changing the input and output caps will make no difference except to add more noise. The input and output caps rolloff at under 10Hz.
  7. kringle77

    kringle77 Supporting Member

    Jul 30, 2004
    Massena NY
    I changed c2 and c3. It did make a difference. Alittle more low end would be nice but, I think this is as far as I can go with it before the distortion gets "farty". Sounds much better for guitar now. I may mod it some more.