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My Pedal Build failure thread.

Discussion in 'Effects [BG]' started by McHaven, Apr 4, 2009.


  1. McHaven

    McHaven

    Mar 1, 2005
    I recently spent money I shouldn't have spent on a GGG tuned muff kit. It arrived this morning and I've spent the last 5 hours working on it. I put it all together according to their instructions and now, it does not work. I've checked my solder joints. I don't see any bad cold solder joints, I don't see solder touching two points together anywhere. Of course, I'm practically blind and I may be wrong.

    Point is, this is the 3rd pedal I've worked on. I failed attempting to rehouse another muff clone. It broke in the process somehow. I tried to build a Parapedal clone. Never happened. I tried this GGG muff, and even with the great instructions I was give, I failed.

    Some people just aren't meant to do things, and I guess I'm not meant to build effects. I'm going to give this pedal to my friend, if he's willing, and see what he can do with it. Maybe he can see what's wrong and fix my mistake. Otherwise I've wasted 70 dollars.

    Only thing I've succeeded in is burning myself.
     
  2. Toasted

    Toasted

    May 26, 2003
    Leeds, UK
    It's almost definitely an off-board wiring problem, or a transistor put in the wrong way around.
     
  3. J. Crawford

    J. Crawford Supporting Member

    Feb 15, 2008
    OH/WV
    KoRn knows a thing about Twisted Transistors.

    ;)
     
  4. dannybuoy

    dannybuoy

    Aug 3, 2005
    England
    Check the orientation of your diodes and electrolytic caps too. I'm about to dive into the DIY scene too, we'll see how it goes! Persevere, as you get more experienced you'll spot the common mistakes more easily and learn how to avoid them.
     
  5. B.C.

    B.C. Supporting Member

    Jun 28, 2005
    Indiana
    +1, diodes are quite easy to mistake orientation, and knowing a muff clone, there is atleast two in opposite orientation. These are the clipping diodes, so you might try flipping both of them.

    Trust me, its an art. :)
     
  6. The Lurker

    The Lurker

    Aug 16, 2002
    Ankh-Morpork
    Or if not an art, at least an iterative process;)
     
  7. seanm

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

    Feb 19, 2004
    Ottawa, Canada
    +1 I assume you don't have an oscilloscope, so you need an audio probe and a signal source.

    The signal source can be a radio, CD player, anything that can produce a continuous signal. Plug that into the input of the effect.

    You also need a probe:

    audioprb.

    The probe needs to plug into some sort of amplifier with a speaker. The blue wire needs to go to a ground. Then you touch the exposed cap to various parts of the circuit and listen to the result.

    Now you just walk through the schematic and see where the problem is. For example, in your case the output of C3 is a good place to start. So you get a signal there? Then try C4? Then try C7? C12?

    When you find the point where it works, and the point where it doesn't, the problem is in between. Simple.
     
  8. B.C.

    B.C. Supporting Member

    Jun 28, 2005
    Indiana
    Wow, thats pretty clever, I like :)
     
  9. What is a "GGG tuned muff kit"?
     
  10. dannybuoy

    dannybuoy

    Aug 3, 2005
    England
    Seek and ye shall find!

    It's a kit produced by General Guitar Gadgets to make a tweaked version of the Big Muff Pi fuzz pedal. More gain and more mids than your typical muff, 99% the same as the Sanford & Sonny Bluebeard fuzz that is much loved by the players of the doom/stoner genre.
     
  11. rcubed

    rcubed

    May 8, 2008
    Vista, CA
    Coming from the Double Muff, it's a pedal I really liked. But after trying some bass fuzzes, I felt it still lost too much lowend and I didn't like the scooped mids. So a change in the tonestack and the addition of a mids knob has really made this pedal work for me.

    McHaven, don't give up on it. It's going to be worth it if you can figure out your mistake, not only for potential future projects but you'll also have a new fuzz pedal. Sounds like you checked the board but not the off board wiring. As mentioned, that's probably where your mistake is.

    Do you have a volt meter? Check to see if the transistors are getting a voltage. You should see less than 9V (I'm guessing ~4.5V) at the collector of each transistor in respect to ground. Also check for DC voltage before the coupling capacitors and AC voltage after the coupling capacitors. Take a look at C3, C4, C7, C12 and C13.
     
  12. grygrx

    grygrx Lookout! Here comes the Fuzz! Staff Member Supporting Member

    Dec 24, 2003
    Columbia, MO
    I assume the cap is on the tip port and the ground is the sleeve port

    I need to make one of these personally. Looking at the picture I'm confused what the the heck is going on. Is that thin grey line just the tape?
     
  13. Chronicle

    Chronicle

    Sep 13, 2006
    NY
    MAKE SURE YOU HAVE THE COMPONENTS...


    soldered the right way...don't put them on backwards..happens to me
     
  14. rcubed

    rcubed

    May 8, 2008
    Vista, CA
    One lead of the cap is going to the tip, the other is free for probing. That cap is there to block any DC current/voltage from going to the amp. Use tape or shrink tubing so you don't short anything to ground.
     
  15. seanm

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

    Feb 19, 2004
    Ottawa, Canada
    I would really recommend that anybody that is looking at building effects buy a scope. For audio use you only need an "obsolete" 2MHz analog scope. These can be bought dirt cheap used. I got mine for $50.
     
  16. rcubed

    rcubed

    May 8, 2008
    Vista, CA
    Good call. I need to do that myself. But for now I have a scope and function generator at work I can use.
     
  17. Wren and Cuff

    Wren and Cuff Commercial User

    Oct 4, 2007
    LA, California
    Creator/Owner: Wren and Cuff FX
    You probably have a much simpler problem than you realize. Most of the above suggested problems could be it, but with most of those, the pedal would still "work" it would just sound all messed up.

    Check your grounds. Check your grounds again. Then after that check your grounds. Make sure every ground on the board, and every jack, and the vol pot ground are connected. It's easy to make the mistake of having a ground point or two connected to OTHER ground points, but not connected to ALL points.

    If the kit has the jacks grounded to the enclosure, solder a wire to the jack grounds and hardwire the wires to the board just to be sure.

    This is all assuming you don't have a DMM or a simple connection tester (available at any hardware store for about $3). You can build one, but i'd spend the 3 bucks so you can concentrate on the pedal, not the tester.

    Thomas Edison tried and failed to get the light bulb to work over 1200 times before he succeeded.

    oh yeah, I forget to mention, check the grounds.

    best,

    matt
     
  18. B.C.

    B.C. Supporting Member

    Jun 28, 2005
    Indiana
    Single best piece of advice here. Grounds haunted me in my first builds and to this day I still have to double check all of them. Very good call.
     
  19. McHaven

    McHaven

    Mar 1, 2005
    Thanks for all the support guys. I'm going to resume working on it later this week, once I'm home for Easter holidays. At least then I'll get to have my bass and amp right beside me as well. I had to build, drive to the rehearsal space at school, test it, then drive back to try and fix it. Really inconvenient.
     
  20. McHaven

    McHaven

    Mar 1, 2005
    Also, I'm going to pull out the magnifying glass and absolutely double check that none of my solder points are touching. Its a real tight fit for some of these components IMO and I'm not the best at soldering so....

    Reexamining my board, it looks like I may have some points possibly touching and I'm pretty sure that's no good, right? Causing a short of some kind or something.

    I had also left out the DC jack, and just wired in the battery, but I'll be going back and wiring it exactly to the wiring diagram to eliminate any possible problems.

    Then I'll get someone who knows what he's doing to really take a look at this terrible job I've done.
     

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