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Russian muff power mod & polarity

Discussion in 'Effects [BG]' started by bhass, Oct 24, 2009.


  1. bhass

    bhass

    Oct 21, 2008
    England, UK
    I bought a russian big muff a few months ago, and recently I decided to add a 9v power jack to it. I chopped off the end of the battery clip, and connected the wires to the jack. Red to the positive and black to the negative. Although only now has it occurred to me that wouldn't this make the jack a positive tipped one? So I can't daisy chain it? Would having black to positive and red to negative make it so I can use it with my other pedals?

    Thanks.
     
  2. rcubed

    rcubed

    May 8, 2008
    San Diego, CA
  3. bhass

    bhass

    Oct 21, 2008
    England, UK
    My jack only has 1 positive. I presume the other two are the negatives? They are arranged in a triangle.

    I put a continuity tested from the jack to the one I thought was the positive and it detected a connection. The other two don't produce a connection with the jack. The tester however beeps when I make a connection to the ones I believe are the negatives.

    Because of this I can't understand anything from that link. :(
     
  4. Surely Boss pedals etc are all centre negative?
     
  5. bhass

    bhass

    Oct 21, 2008
    England, UK
    What do you mean by centre negative?
    If I solder the red wire to the positive, and the black wire to the negative, will I be able to daisy chain the pedal?
     
  6. bhass

    bhass

    Oct 21, 2008
    England, UK
    Can I get a bump?
     
  7. bhass

    bhass

    Oct 21, 2008
    England, UK
    I read that link to try and understand it more and here is what I have so far:

    Remember that I'm using the wires for the battery clip (I cut off the battery clip end). The black will be connected to the ground on the circuit board, and the red will power the circuit. Therefore I need to connect the black to one of my negatives, and the red to the positive. That would make it center positive so I can daisy chain it with other pedals?

    I don't want the use of a battery, simply the use of the DC jack. The link confuses me :(.
     
  8. bhass

    bhass

    Oct 21, 2008
    England, UK
    I just did the soldering. Black to negative and red to positive. It doesn't work. I have no idea why.

    How can I be sure which of the 3 lugs is the positive + negative etc. When I touch the bit that the plug goes into inside the jack with the continuity tester, and to the lug i soldered to the red wire, it beeps. I presume this is the positive? The other two don't beep unless touched with each other. Negatives?

    I am using the wires from the battery snap (which was cut off) and soldered directly to the lugs.

    Edit: This is what I got:
    http://www.maplin.co.uk/Module.aspx?ModuleNo=1407
     
  9. A couple of things:

    1. The wires are positive and negative. The connector has no inherent charge until you apply power to it. If you want to make the unit center positive you can. If you want to make your unit center negative you can. The connector is just a device that channels the power from source to load. The connector leads aren't positive or negative until you give them a charge.

    2. The negative isn't necessarily grounded in the pedal. If the negative isn't grounded, this won't work daisy chained no matter what. I think Jimmy Rocket tried this with a russian Muff and it didn't work because of a grounding issue. I could be mistaken, however. You should be able to use an ohmmeter to determine which battery lead is grounded (if you have an ohmmeter).

    3. You are correct that the phone adapter for daisy chains makes the power positive tip or center positive.

    I think that the red should go to the tip and the black should go to the ring, but you may want to take the power connector off of the casing to see if it will work ungrounded.

    Hope this has been helpful and hope you get it working.

    EDIT::: Just read your whole final post with more detail. There are three pins on that connector. One should be tied to the sleeve. The sleeve is the part that gets the locknut. If your red wire is electrically continuous with that one the power supply wont work. The negative (black) wire should go to that one. If the unit is negative ground, this will work. If it is not, then this project is doomed.

    The two others are the tip and ring. The tip is the piece that makes contact with the tip of the power connector, the ring is the lead that connects with a piece in between the tip and sleeve on a stereo connector. You're power cord doesn't have a stereo connection so you can ignore that piece. You will want to connect the positive (red) wire to the tip connection.

    Good luck.
     
  10. bhass

    bhass

    Oct 21, 2008
    England, UK
    About the lack of grounding thing, there is a red wire that comes off the circuit board, and has a small metal ring on the end. It just sticks out and makes contact with the enclosure when it is closed. Could this be the ground?

    Also, how do I go about testing for whether the black wire is grounded? I have all the necessary equipment...just lack of intelligence.

    + thanks for the post.

    Edit:
    http://bassfuzz.com/wp-content/gallery/ehx_rmuff/DSC00194.jpg
    Courtesy of the man himself. The bottom left, that white wire that simply sticks off the circuit board. In this case mine is red.

    Edit edit:
    Just read your edit. I'm off to change the wires to what you said. I'll be back to post a progress report!
     
  11. Testing for negative ground or positive ground should be simple.

    You'll need to electrically isolate both the power leads from the casing. If you leave them on the connector and just pull the connector off the casing this should work. Then ohm test from the black lead to the pedal casing and then the red lead to the pedal casing. The one that is grounded should have 1 or less ohms to the casing. The other should have more.

    That white wire is likely the ground reference.

    I edited my previous post because I read in more detail your early troubleshooting. Take a look.
     
  12. bhass

    bhass

    Oct 21, 2008
    England, UK
    I still don't understand if I even have the wires soldered onto the correct lugs. I don't know the difference between the ring or the tip is.

    I tried to interpret what to do for the ground test, but I got no results at all from the multimeter. I took the jack of the enclosure, and touched each lug and then touched the casing and I got no reading for each.

    Does this picture tell you about which wires go to where: http://www.maplin.co.uk/images/full/jk09k.jpg
     
  13. Errmm. The ground thing is weird. I've only worked on a few pedals, but they've always had an easy ground reference. Maybe the paint is causing some problems with your meter, or maybe the references are all to each other (weird). Try reading from the wire to a spot with no paint on it. The location of the wire being grounded is a good start.

    The tip should be the one that turns into the casing the farthest into the pedal. Try them both, it shouldn't hurt either.

    I'm leaving soon, good luck though.
     
  14. rcubed

    rcubed

    May 8, 2008
    San Diego, CA
    You either have the wrong power jack for the job (you need one like the one in the link I posted that has two power lugs and one ground lug so you can daisy chain it with other center negative pedals). or you're getting power and ground backwards. Hopefully you didn't fry any components.
     
  15. bhass

    bhass

    Oct 21, 2008
    England, UK
    Turns out I did have some connections the wrong way round. Fixed it and now it works perfectly. Thanks for all the help and patience.
     
  16. there centre negative and you want to wire red(positive) to one of the smaller lugs(the two smaller are the positive terminals) and the black(ground) to the bigger one, you'll also want to move the other end directly to the ground, so you don't have issues if the input jack comes out
     

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