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Cry Baby GCB-95 modification

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  • Cry Baby GCB-95 modification

    Could someone please tell me (graphically) which capacitor I need to replace to stop the pedal sounding so thin.
    I say 'graphically' as I am not an electronics engineer so I won't know what you mean if you start describing where it falls within the component chain.
    I have obtained the component that I need to install I just need to know which to swap it for.

    I know from various Wah modding forums that swapping out one of the caps restores some of the bass.
    However the PCBs shown have a different layout to mine with mounted in and output jacks.
    Mine is the same as the one shown in the attached jpg

    Please help! :-)
    Attached Files

  • #2
    Originally posted by sohosteve View Post
    Could someone please tell me (graphically) which capacitor I need to replace to stop the pedal sounding so thin.
    I say 'graphically' as I am not an electronics engineer so I won't know what you mean if you start describing where it falls within the component chain.
    I have obtained the component that I need to install I just need to know which to swap it for.

    I know from various Wah modding forums that swapping out one of the caps restores some of the bass.
    However the PCBs shown have a different layout to mine with mounted in and output jacks.
    Mine is the same as the one shown in the attached jpg

    Please help! :-)
    Should be a part number on the other side of the board. May be a dumb question but how do you know if you have the right part?
    Try this site it may explain more of what your looking for. Your board looks pre 90s

    ElectroSmash - Dunlop Crybaby GCB-95 Circuit Analysis.

    nosaj
    soldering stuff that's broken, breaking stuff that works, Yeah!

    Comment


    • #3
      The question that I would ask, is how do you want the pedal to be bassier? When the pedal is toe down or when it is toe up?

      what I mean is do you want the pedal to be bassier all of the time throughout the sweep or deeper only when you pull back on the pedal?

      Comment


      • #4
        Yeah, you can adjust the pot that it doesn't go so far into the treble zone.
        Take the pedal all the way down.
        Look at which direction the pot turns.
        Loosen the screw for the rack & back off the pot a bit.

        Comment


        • #5
          I'm assuming you want to swap the feedback capacitor. The stock value is 0.01uf and changing this to 0.015uf or 0.022uf moves the sweep to the bass-side.

          The capacitor connects to the junction of the 10K Ohm resistor and emitter of one of the transistors. There is only one resistor of this value on your circuit board, located at the bottom left of the picture The colour coding is brown/black/red with a gold tolerance band at the end.

          The circuit board track is just about visible enough to determine the red film-type capacitor you need to replace is located bottom/centre of the board, just to the RH end of the connector. You should be able to confirm the value of the cap from the marking and determine that it connects to the 10k resistor from the underside of the board.

          Comment


          • #6
            Originally posted by Mick Bailey View Post
            the 10K Ohm resistor and emitter of one of the transistors. There is only one resistor of this value on your circuit board, located at the bottom left of the picture The colour coding is brown/black/red
            I think you mean brown/black/orange.

            I hope that there is some photo glitch making some of those caps look like they are cracked in half?
            Originally posted by Enzo
            I have a sign in my shop that says, "Never think up reasons not to check something."


            Comment


            • #7
              Originally posted by g1 View Post
              I think you mean brown/black/orange.
              Ah!... Yes. What was I thinking?

              Comment


              • #8
                Originally posted by g1 View Post
                I think you mean brown/black/orange.

                I hope that there is some photo glitch making some of those caps look like they are cracked in half?
                I saw that too but decided not to say anything since the break looked too clean and the only ones I've ever seen break like that were some old tropical fish lookin ones.

                nosaj
                soldering stuff that's broken, breaking stuff that works, Yeah!

                Comment


                • #9
                  Thought I saw those caps cracking up before

                  http://www.geofex.com/Article_Folder...d/wahboard.jpg

                  From a R.J.Keen article

                  Stop Tone Sucking cheaply and easily in your wah pedal


                  stash of wah/waa here..

                  crybaby_sch.gif gif by alfalfasprout69 | Photobucket


                  EDIT:
                  Getting side tracked can't help myself...

                  Great video here about the waa .. Explains Jem , Clyde McCoy ,
                  how come Vox & Cry Baby etc and how if Thomas Organs hadn't decided to save $3.80 on a switch in Vox amps the wha/waa may not have been invented then.

                  Part one here

                  https://www.youtube.com/watch?v=FOHZ...&nohtml5=False

                  beware of the one that has no audio !

                  I normally don't post links to tribute artists but as you can guess I'm going to
                  as this guy has gone to all the trouble to include the Vox MRB in his video.
                  Well better than me writing a thousand words !
                  a short quote..

                  "A bit of technical info: The song features a very distinctive piano sound. On the original recording, this was achieved by running the piano track through a Vox Conqueror guitar amplifier. This amp had a special 3-position tone selector effect, known as MRB, or Mid-Range Boost. It was similar in principle to the effect circuit found in the Vox wah-wah pedal, however it only had three discrete positions (whereas the wah-wah pedal is continuously variable). Unlike the wah-wah pedal, the MRB effect was designed to be used as a tone control--select position 1, 2 or 3 and leave it on that setting for the duration of the song. Recording engineer Ken Scott came up with the idea to manually "play" the MRB switch in time with the music (and is the one doing so on the recording).

                  Even though I could have simulated this effect using various digital audio plug-ins, I sincerely wanted to be able to show how this effect was created using a real Vox Conqueror amplifier. Unfortunately, these amplifiers are hard to find, however, I was fortunate to be able to use a Vox Defiant (from the same product line as the Conqueror, featuring the same MRB effect)."

                  https://www.youtube.com/watch?v=8ldHeXbnMQY
                  Last edited by oc disorder; 04-10-2016, 09:03 PM. Reason: side track !

                  Comment


                  • #10
                    That really looks like a glitch in the photo..
                    The resistors have a slight offset too.

                    Comment

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