Connect with us

DWD - EP Multiwah footswitch

Discussion in 'General Electronics Discussion' started by tedstruk, Jan 5, 2013.

Scroll to continue with content
  1. tedstruk

    tedstruk

    475
    7
    Jan 7, 2012
    finally found the right forum...

    OK I cut the board out of the pedal and discovered some real bad looking connections on it, that I will have to remove.
    I wrote a schematic for it as it is before I do anything, and I downloaded a couple of free schematics on volume and phase circuits.

    Sometimes its better to start from scratch, so I dug around in my shop and found 3 more pots -3pin 200k.

    I pulled the 5 way, and made a diagram of the pinouts 1 to 5. there are 10 pins,
    Position 1 and 6 have no effect.
    Might be a bad switch.
    I can't find any volume pots anywhere. Only balance pots, I don't like using balance pots as volume pots, I never can get the response I want, and I always lose some tone or something.

    You don't see much highvoltage, loud and clear stage equipment anymore. It's lonely out here.
     
  2. tedstruk

    tedstruk

    475
    7
    Jan 7, 2012
    updated schematic

    I made a few mistakes on the last schematic I posted...
    this is an updated version... I will keep looking until I have it right.

    PdlBrd.JPG
     
  3. tedstruk

    tedstruk

    475
    7
    Jan 7, 2012
    Properly connected board?

    This schem shows where I think I would put the wah pot and the battery, but I don't know where I would put the jack inputs and outputs. It also has a battery isolator for an external 9v wall wart. The 5 way works, but the plastic has pulled away from the potmetal housing, so I am considering buying a new one next time I am in a part house...
    If you are a good dedicated electronics engineer or something, maybe you could give me a hint as to where to connect the in and out...ground to negative, and everywhere.
    :)
     
  4. tedstruk

    tedstruk

    475
    7
    Jan 7, 2012
    forgot schem!

    the board has 6 large holes
    A B C
    D E F
    A is isolated
    B is connected to one of the CEcap's after the cap, into the base of the transistor
    C is isolated to pins A and H
    D is connected to .01 cap and pin F
    E is Isolated to Pin G
    F is connected to the other CEcap, after the cap, into either the collector or emitter?
    I think collector?
    Any help nessesary is truly nessesary!!
     

    Attached Files:

    Last edited: Jan 15, 2013
  5. tedstruk

    tedstruk

    475
    7
    Jan 7, 2012
    On this diagram I added the possible wah connections and the mains.

    Main A is always isolated, which as I remember(from school), must be isolated, for the circuit not to ground out.. I don't know what goes in the mains though. :( IDEA!!!

    Is it a harness?:p


    PdlBrd2.GIF
     
  6. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    25,448
    2,809
    Jan 21, 2010
    The +9v looks wrong. It's not going to connect to a capacitor like that.
     
  7. tedstruk

    tedstruk

    475
    7
    Jan 7, 2012
    9v...power supply

    Ok. I always thought that the power source was isolated with caps to keep it from burning up the other smaller components. what are the 100v and 16v caps doing on a 9v board?
     
  8. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    25,448
    2,809
    Jan 21, 2010
    As long as they're over 9V it's OK. The 100v capacitor is likely to be a small value that may only come in a 100V rating
     
  9. tedstruk

    tedstruk

    475
    7
    Jan 7, 2012
    found a bad resistor....

    This resistor does not look bad, but I cannot get a continuity signal through it.

    badbrd1.GIF

    checked some other components, then tried it again, and its not blown?

    call the ghosts of the pcb controlling agency......
     
    Last edited: Jan 9, 2013
  10. davenn

    davenn Moderator

    13,710
    1,911
    Sep 5, 2009
    DC doesnt flow through capacitors ... they are open circuits

    Dave
     
  11. tedstruk

    tedstruk

    475
    7
    Jan 7, 2012
    how many Ma of wall wart would be good for this board?
     
  12. tedstruk

    tedstruk

    475
    7
    Jan 7, 2012
    assumptions, what a conundrum!

    Assuming... I am right in that the caps are the 5 way tonal changes...

    then the rest of the circuit must be inputs, outputs and switching.

    If the 2 1294s are power caps, instead of wah resistors, then I think it is safe to assume these are the pins that are all supposed to be populated(there should be something in each of these holes.) So they are probably where I put the stickystuff...
    how does this look?:D

    A=common
    B=9v
    C=ground
    D=input
    E=common
    F=output

    pins

    a=common
    b=open
    c=open
    d=wahpot in
    e=output
    f=input
    g=common
    h=ground
    j=wahpot out
    k=5way
    l=5way
    m=5way
    n=5way
     
  13. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    25,448
    2,809
    Jan 21, 2010
    What is the maximum current it draws? multiply that by 1.2 and use that as a minimum current rating for the wall wart (more is OK)
     
  14. tedstruk

    tedstruk

    475
    7
    Jan 7, 2012
    current rating...

    ahem, how do I compute the current...

    That would be the amount of induction?? like a 500 induction coil would draw 500ma?
    if thats true, then 1.2amps would be just right.
    I have a 450ma wart, is it possible to increase it to 1.2?
     
  15. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    25,448
    2,809
    Jan 21, 2010
    The easiest way is to measure it.

    This circuit seems to be battery powered. Connect your multimeter in series with the battery and measure the current.

    If it's powered by a small 9V battery then it probably draws no more than 20mA. Since you're not going to find a wall wart rated at less than maybe a couple of hundred mA, almost anything will do.

    However, since the circuit is not designed to operate from mains, it may be insufficiently filtered and hum from the external power supply might be heard at the output. To fix this you may need to add more filtering.
     
  16. tedstruk

    tedstruk

    475
    7
    Jan 7, 2012
    milli wow!

    Hey my figures were close to the 20 you said, the board resistors came out 21.2ma!

    OK I have a 9v 450ma I can use, but I might need to add some filters. alright!

    here is my latest schem on the test modes...

    I don't like the first test, because it uses the block for a power source, I think I remember something about not using the block for power in my antient teachings.:eek:

    I am stuck with the second then. I think I should test with a smaller power, like a 1.5v just to be sure I don't cook anything.

    BORDEDIT(4).gif
     
    Last edited: Jan 11, 2013
  17. tedstruk

    tedstruk

    475
    7
    Jan 7, 2012
    What size fuse would I put between D and F in the block?
     
  18. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    25,448
    2,809
    Jan 21, 2010
    I would test it with a small 9V battery first.

    I see no need for a fuse, and the leads your suggesting for that are what you have labelled as input and output, certainly not a place to put a fuse.

    If you really want one, place it in series with the battery connection. Something rated for 100mA would be fine (if you can find one) otherwise the lowest current above that you can get hold of at a reasonable price. I'd probably go for a fast blow (but as I said, it's likely superfluous unless you're connecting stuff randomly)
     
  19. tedstruk

    tedstruk

    475
    7
    Jan 7, 2012
    I don't know where to connect the terminals.


    I have a board with no schematic that says "input goes here", "battery here" ect.

    Me? I would connect the battery in the wrong place and bunr something up!
    I wanted a schematic, but I couldn't find one... I can draw one, I knwo what everything does, but I am just not a tech...
    sorry!!!
     
  20. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    25,448
    2,809
    Jan 21, 2010
    Post some good sharp photos of goth sides of the board and we'll see what we can do for you.
     
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Similar Threads
Loading...
Electronics Point Logo
Continue to site
Quote of the day

-