How would you go about making EC Circuit in Expression Pedal

Discussion in 'Effects, Pedals, Strings & Things' started by Handonam, Sep 19, 2008.

  1. Handonam

    Handonam Member

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    Before you go on and post "Doesn't this EQ/Boost/Overdrive/Distortion Pedal do primarily the same thing as the Eric Clapton Mid Boost Circuit in the Guitar?" or "This has been discussed already!" Please read this original post carefully.

    I know there's this big discussion from another thread about the alternatives for the EC midboost circuitry. However, the goal for this thread is to discuss the ability to put the ACTUAL EC MIDBOOST CIRCUIT into an expression pedal, and how one may go about successfully putting that in there. I know it may be "possible". There's no question about that, but HOW would you do it? That's the main question of this thread. It's not "well this other pedal works just the same..." Think of it as "Let's build this EC Midboost pedal and see if that is the same as the original. If it doesn't, then it was worth a try since no one else has done it." Got it? Good :)

    By the way, i'm not interested in shoving the actual thing into my guitar and calling it quits. That just strays away from the purpose of this thread.
    THE RESEARCH

    I've done a fair bit of googling around to see if anyone has ever done this before, but so far I have not found anything. I would love someone to prove me wrong by showing me someone who has actually done it (with some information on how he has done it WITH THE ACTUAL BOOST, NOT A CLONE or anything). So, I am hoping to get some help from anyone who is interested in this little project.

    THE PLAN
    -3 pots into 1 (sort of)
    The thing about this circuitry is that it is made for a guitar with 3 potentiometers in use. An expression pedal only uses 1 of those potentiometers. So the tricky part is knowing how to manage some of those wires to work with 1 pot in a wah. the pedal doesn't need to really have a treble tone cut or a master volume control. We only need to use the midboost tone control.
    -Active/Passive
    The other challenge is the minor flaw (if you even call it a flaw) where the EC Circuit will only make the pickups active, and not passive. I'm looking to see if we can use the pedal bypass method to hop over that. But then again, the pedal probably won't make the pickups "active" as it is not within the guitar anymore.
    -Battery Bypass
    For the Circuit implemented into the guitar, the battery will engage when the input jack is inserted, and will only disengage when the jack is removed. The expression pedal method should be able to switch off from the battery (or from the AC outlet if that is the preferred method of power) from the same switch as the bypass of the previous paragraph. I think that may be simple.



    Now for Reference, this is the wiring diagram for the EC Guitar. I'm not sure what to do with the Green and Black (which is to the left of the green) wires.


    I'm sorry if my capslock seems like yelling to you guys. I'm truly not, haha. It's just to emphasize the point in case people don't want to read this long post.

    I hope some of you can help me out on this little project! I really admire the help that goes around here in tgp. Let's get movin'!
     
    Last edited: Sep 19, 2008
  2. walterw

    walterw Gold Supporting Member

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    that black wire to the left of the green will be the actual signal input to the effect.

    if you hook the green wire to the (brown?) wire 2 wires to its right on the card, right on the lug of the mid-boost pot, and then put a 50k resistor from that lug to ground, it will be the same as the volume pot on 10. you might even be able to skip the resistor, which will be the same as no volume pot.

    are you talking about a pedal with an expression control and a separate stomp switch? 'cause if you build it into a typical wah pedal, stomping forward to click it on will result in it coming in at full blast whether you want it to or not.

    if you try to rig up the switch to turn the power on and off at the same time as the effect is kicked in and out, you could get weird power-up noises. i would suggest doing it normally, that is, having the effect power up when something is plugged into the input, and then having your stomp switch kick the effect in or out true-bypass. that way, you could also use a triple-pole stomp switch to turn a light on or off at the same time.
     
  3. Handonam

    Handonam Member

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    Yea, i forgot about this note. Thanks for reminding me!

    1) Where would i connect the black wire to?

    2)Do you think it might be better to reverse the pot so that when i kick it on (the effect, not the power i guess), then at 0 degrees the effect would be low, and at 45 degrees (or whatever it is), the boost effect will be at it's fullest? This would be the opposite of how a volume pedal will function. It would just be a matter of switching the left and right lug, woudln't it? If not, i guess i'll have to turn the whole pot the other way.

    3)Also there's that battery snap that i forgot about. I'm thinking it should function the same way as a stomp pedal by activating it through a cable, as you have suggested. I guess i'll install a little flip switch somewhere to activate and deactivate the POWER for it. might be a good idea :)


    Is there a reason why the clapton boost requires the 50k volume pot? what kind of sound does it make on a standard pot?
     
    Last edited: Sep 20, 2008
  4. Handonam

    Handonam Member

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    anyone? :)

    woops, i just read the rule on bumping. sorry :(
     
  5. Handonam

    Handonam Member

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    yoohoo?

    what would i do with the black wire and the other stuff :(
     
  6. Handonam

    Handonam Member

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  7. walterw

    walterw Gold Supporting Member

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    sorry, i think folks aren't jumping on this because if you know how to wire up a true bypass pedal, you already have all the info you need, and if you don't, then this is an uphill battle.

    the black wire is signal into the effect, the white wire is output from the effect. the other wires are for the boost pot.

    the rest is just the battery wire, the ground, and wiring up the true bypass switch, with or without the LED.
     
  8. Handonam

    Handonam Member

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    Cool, that answers my above questions. Thanks!

    just need to find a good expression pedal to fit this into. Anyone have any recommendations for that? What are the criterias i should look for in those things?
     

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