Saturday, 4 March 2017

Dunlop Dunlop GBC-95 Modded Crybaby

For those that are just never satisfied by whats out there in the land of wahs I took the standard Dunlop GBC-95 Crybaby and added some features based on common mod points. So how's this supposed to work?

Voice Pot: Changes the voice of the the wah by changing the sharpness and making it more "vocal." The larger the value the more "vocal" the wah sounds.

Gain Pot: Really this controls the overall bass and gain of the wah. The lower the value the more growl and bass you'll get.

Sweep Switch (SW): This controls the sweep range of the wah. The larger the cap the more bass sweep you'll get. For instance the common value is 10nF, which i put on the board already, and the bass wah has a 68nF. Personally if I were making this I would start with the stock value and increase using values I liked up to the bass value, but hey, that's just me.

Sweep Pot: This will control the range of the week of the wah pot. No different then what you find on the Dimeback or Cantrell Wah.

R1: This will set the volume of the wah, the smaller the value the more volume you'll get. Typically it's 68k. So you can mess around with it and get as much or as little volume as you liked.




34 comments:

  1. COOL. I would like to add that after buying 5 different inductors i found the biggest change is really the transistor gains. for a clyde mccoy you should use transistors with a 190-250 hfe . the 1960 wahs are less distorted and have more splash in the toe down position because they have lesser gain transistors.

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    1. Very true. The other major factor is the inductors inductance. If you look at the schematics for all the classic wahs you'll see the most differences in the values in places where I put pots and the capacitor switch. Keep tuned for the big post with 5 or 6 classic wahs and you'll see what l mean.

      Been making all of these to force myself to take study breaks, got 4 more exams this week. I think I'm slowly going insane. Lol

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  2. Some different value comparisons of popular wahs from FSB
    http://i.imgur.com/BRg9i.gif

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  4. This is might be timely. I'm about to pickup a shell from busted wah and need a circuit. Is this like a classic, Cantrell, Dimebag, etc all in one?

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    1. Short answer is yes. All the mods for this way can allow you dial in the way how ever you want.

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    2. I'm a little scared to be the first to attempt this one. Not sure I have the skill set. Just made a couple of circuits so far. Couple questions while I'm thinking about it:

      1. Does it matter if the 6 pos switch is make-before-break or break-before-make? I assume either works here.

      2. What is the taper for the Wah and Sweep pots, lin?

      3. I saw the note that you're not sure on taper for voice & gain. Best guess? Lin?

      4. Do you think voice and gain should be external controls or should they be internal pots that are tuned to taste and left set?

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    3. hey man nothing nothing different about this circuit compared to any others really, so to be afraid of.

      let me address you're questions:

      1. you're going to use a make-before-break switch so something like this: http://www.taydaelectronics.com/electromechanical/switches-key-pad/rotary-switch/rotary-switch-2-pole-6-positions-alpha-sr2611f.html

      2. the wah pot is just a wah pot, not a normal alpha pot.

      3. since this was kinda an idea i had in my head i'm not sure of what the taper of the added pots sound be. so if you build this at this point, try either a linear or log and see how the transition is. if the transition isn't smooth and seems to bunched up at one end swap it for a the other type and see how if it's any better. this also means the lugs may be reversed. super easy things to address in a build.

      4. i had in my head that all the controls would be external for 3 reasons. first it makes for easier changes while you're playing. second if you find a few settings you like you can switch between the them without having to open it up. three with the idea of being able to constantly change these settings trimmers aren't going to really hold up, cause they're not meant to be changed a lot.

      if you want to do a set it and forget it you can put trimmers on a daughter board and make the same connections, sent them where you want and close up the way.

      btw, since all but 1 of the wah's i recently posted are essentially the same layout if you build this one then all of them will be verified. i'm sure if you build it and verify it everyone will be even more excited. plus, everyone should try and get one verification while being a member of the group, no?

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    4. I'll do it. Need to order some parts and carve out a little time.

      On Q1, the switch you listed is specifically a break-before-make. Is that what you meant? The make-before-break version is probably this one.
      https://www.taydaelectronics.com/rotary-switch-2-pole-6-position-alpha-sr2511.html

      Q2. What about the sweep pot? Is that linear or something else. For the wah pot, I guess I can't get by with something cheap. Looks like an S taper is what most use. The wah specific pots are pricey, although Smallbear has a wah pot that appears to be just a normal linear.

      If I can get this thing working, I might add in the Foxrox buffer, to have the wah with everything....

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    5. yes, but i don't use those switches i use the ones that i posted a link to.

      the only pot that i know of the what taper it should have is the wah pot. the additional pots taper (sweep, gain, and voice) are unknown. so try either linear or log, and if the the change isn't smooth try the other.

      personally, i would get the pot and inductor from joe gagan. i feel like i'm advertising for him now, lol. but, in all honesty i only use his pots and inductors for any and every wah i do, and i don't make suggestions i don't do myself. reasons being that not only is his stuff high quality, he's not expensive, will help you as much as you need, and he's a big member of the DIY community and i like supporting our community whenever possible. you can even ask him for specific winds for the inductor and hell make no problem. he's even wound a few with custom higher then normal inductance without even batting an eye. here's his store

      http://stores.ebay.com/joe-gagan-wah?_trksid=p2047675.l2563


      also i caught an error in the placement of the switch and have updated the layout, so it should be good to go.

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    7. Thanks for the info. Funny that you mention Joe. I used to see his band play but lost touch with him. Didn't know he was still in the biz. My first build was his Easy Face design.

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    8. One more Q. What's the truth about cap styles? In my other builds I tend to use box style caps when I can. I see that orange drop or tropical fish are very common in wah circuits. Is that just vintage mojo or is does it matter?

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    9. yea man, joe is one of the nicest guys in the world. been a huge help in a few of my wah experiments. ugh, and his tonetank inductors are just so sweet sounding. i've tried a bunch of other ones before and hated them all. yellow and red fasels, some nos ones, the ones smallbear sells, etc. and none of them have had that tone i wanted. not to mention his pots are just better and smoother. i have no idea how the hell he does it, but he does and i'm super grateful for it.

      anyways, as far as caps go you're going to get a lot of arguments about if there's a difference between them. in my experience it's all about mojo and looks, sound is the same. i do some builds with mojo components cause i find it rewarding to know that it's like the original and it looks damn cool when you crack open the back. also, i'll use mojo parts when it there's more space and i can lay things out like the originals, or if i'm going to do it on tagboard or turrentboard. i usually just use the old panasonic red caps for the nF range, regular electrolytic caps for uF range, multilayer ceramic for the pF range, and metalfilm resistors.

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  5. Hey guys, whats up with the gain pot? Two connection to lug 3 and no other connetions?

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    1. you're right man. i forgot to change one of the wires to lugs 1 & 2 when i copied the wire and text. made the correction.

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  6. You can count this as verified. I finished the circuit using parts out of my old stock crybaby. I did have to lower the value of the gain pot considerably to get any sound below maxed. ended up with a B5K. I used all linear pots for this. I also only had a 3pole 4 position rotary, so only 4 cap choices, but that's enough. sounds way better than the crappy mods I had previously done. Glad to have a cool wah back.

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    1. awesome that it worked. i just looked at the schematic again to see what the resistor value was originally. i meant to put it as a 1k pot, as the resistor value typically ranges from a jumper up to 470r in most wahs. i didn't realize that i made it a 100k pot. i make the changes to the layout. great job on the verification man.

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    2. quick question about the pots. are the lugs wired correctly?

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  7. What's the reason for using Darlingtons, and is there a marked difference between that and something like a BC108? Just curious as to how exactly this would affect tone... I would test it but I don't have a wah shell :( ...yet.

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  8. If I may make a small suggestion. I'd change the emitter resistor from 10k to 5k and change the sweep pot from 5k to 10k. This way you can go lower than 10k as some vintage wah designs have 8k2 on the emitter and you can still reach the 15k as in the design above.

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  9. Looks good - I modded my own wah like this and want to replace as its a little tired.

    two questions:
    1.where is SW A connected to?
    2. any ideas where I would add the volume conversion switch to ground (as per the maestro)?

    lovely wah collection here now - well done

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    1. SwA goes to the A pole if the rotary switch.

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    2. Thanks Zach

      on the other matter:
      looking at the vol mod switch from tonepad here: http://www.tonepad.com/getFile.asp?id=59


      I can see that TonepadP.Q2 equates to Q3 on the diagram here and the dpdt switch (and 4k7; 22nF & 2x220k) needs to be in parallel with B1. And the return from the engaged switch would use the +ve rail of the 4.7 electrolytic cap on the bottom row. After that I'm stuck - I will persevere but if any one could draw it up that would be great.

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  11. You can eliminate the sweep board altogether and solder the caps directly to the switch poles to save some work.

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  12. Thanks for the layout Zach, I have built a few pedals based on your layouts lately. The Wattson EFY-6 is gold, although I think I left a note regarding the an update due to a reversed pot. Thanks mate!

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  13. Everybody who`s looking for a good wah has to try this one. I built it with an inductor from an TAD crybaby and this is a really good wah-sound, also very versatile and good sounding with high gain distortion. Thanks for the layout and keep on the awesome work on this site.

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  15. Hi everyone,

    i already manage many of Tagboardeffect pedals but this one will make me crazy.
    Anyone could help me ?

    I explain my problem, i have no bass on my wah. I guess there is no sound above 300Hz. And wah works much more as a volume pedal than a wah wah.
    I will try to send a pink noise into it and do a FFT to see where the frequencies are cuted.

    For information I already switch 100uF cap, and the both 10nF. 220nF are checked (but not switched).
    I switch transistor too..
    And my inductor is 17.5ohm.

    If you need sample, or pictures i will provide you.

    Thanks in advance,

    Chris

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    1. Is it possible to give me voltage on transistor?
      I already found a 5.1k resistor instead of 1.8m.
      Store where I bought electronic parts made a mistake. And.. My fault too, I don't have check resistor before soldering..

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    2. And fft do not show any thing else than a drop volume and 600 hz highpass.

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    3. Hi all,

      I had some problem with resistor value that were wrong..
      Pcb's dead, I redo my project.

      But this time i 've done "Thomas Organ Cry Baby" and modded it step by step.


      This site helped me to found issu (don't know if i can show this site)
      https://www.electrosmash.com/vox-v847-analysis

      I make it transparent and working well with Fuzz.

      Thanks for you all for your work (Zach, Mirosol and all the other one)


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  16. And try something around 50nf on C1 in to get more bass and natural sound (in my way)

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