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Looking for Xover skematics/diagram

Discussion in 'Amps and Cabs [BG]' started by LongHairFreak, Oct 8, 2013.


  1. LongHairFreak

    LongHairFreak Insert cool nickname? Nobody's given me one yet. Supporting Member

    Aug 7, 2006
    Twin Cities - MN
    Hey TB
    I was inside my EV 2x15 this morning and found what appears to be a capacitor lying on the floor of the cab and another that was connected only at one end. So, I'm trying to find skematics for the Xover in my EVM B2150M and I just can't seem to find it on EVM's wsite. Can anyone help with this?
    Thanks
     
  2. BassmanPaul

    BassmanPaul Gold Supporting Member

    Aug 25, 2007
    Toronto Ontario Canada
    If you can repair the cabinet you should be able to draw out the schematic by tracing the wiring on the board. If one cap is still attached at one end you it should be pretty obvious where the other end goes. Same for the "loose" cap. While you have at it, reflow every solder joint on the board. Soldered joints do have a "shelf life" and need to be renewed every decade or so.
     
  3. LongHairFreak

    LongHairFreak Insert cool nickname? Nobody's given me one yet. Supporting Member

    Aug 7, 2006
    Twin Cities - MN
    Obvious, eh? I don't know.. I can tell where both caps were pressed into a putty of some sort (to keep them in place?) and yes, it is obvious where one of the loose wires go, but since both caps were aligned end-to-end, how would I know which of the two center wires goes to which cap?
    Along those lines, does it matter which end is which when reattaching the wholly loose cap?
     
  4. sconix

    sconix Supporting Member

    Feb 23, 2004
    High Point, NC
    5 seconds with Google... searched EVM B2150M 2nd result is a pdf link of what you need.
     
  5. LongHairFreak

    LongHairFreak Insert cool nickname? Nobody's given me one yet. Supporting Member

    Aug 7, 2006
    Twin Cities - MN
    Sorry, I should've stated... I did do a Google search and found potential information, but being blind, I didn't know if I found a diagram or not and the pdf I found stated 'Empty Document' and nothing else.

    Thanks though. Knowing what I found is likely what I was looking for, I can find it again for whoever is soldering for me.
     
  6. will33

    will33

    May 22, 2006
    austin,tx
    The capacitors used in the crossover are often non-polar, but not always. Have someone verify for you, should say on the side of the cap. If they are non-polar (or bi-polar, same thing), it doesn't matter which way they are facing. Meaning they won't have a front and back, or in and out.

    If they are polarized and you get one the wrong way you will be able to tell by witnessing the small explosion that will happen upon testing for the first time. :D
     
  7. LongHairFreak

    LongHairFreak Insert cool nickname? Nobody's given me one yet. Supporting Member

    Aug 7, 2006
    Twin Cities - MN
    Explosion, eh?? I'll try not to do that! :D
     
  8. BassmanPaul

    BassmanPaul Gold Supporting Member

    Aug 25, 2007
    Toronto Ontario Canada
    You being blind is something I find confusing.
     
  9. LongHairFreak

    LongHairFreak Insert cool nickname? Nobody's given me one yet. Supporting Member

    Aug 7, 2006
    Twin Cities - MN
    ?? Why's that?

     
  10. will33

    will33

    May 22, 2006
    austin,tx
    It's good for people to play in the dark so they can't rely on eyes and cheatsheets. Helps to develop a better ear and feel for the instrument.
     
  11. will33

    will33

    May 22, 2006
    austin,tx
    Probably wondering how you managed to find out as much about the construction as you did without being able to see it.

    Paul is a nice man, he means no disrespect.
     
  12. LongHairFreak

    LongHairFreak Insert cool nickname? Nobody's given me one yet. Supporting Member

    Aug 7, 2006
    Twin Cities - MN
    Oh yeah man. I know. B.Paul is one of those TBers that I have developed a good amount of respect for. I usually find his posts/commentary to be knowledgable as well as non-confrontational. (I wonder if he's blushing as he reads this?)

    As for his confusion at my blindness, you could be right and if so, let me say this.
    I just stuck my arm into a port and began fishing. Just like every day life; I let my fingers look around.

     
  13. You can buy the way make a non polarized crossover cap from polarized ones. Just join the two positive ends and use the negatives for in/out. Not the best way to get there but it can be done. The value will will also be halved i.e. two 50 mfd caps will make a 25 mfd NP cap.
     
  14. BassmanPaul

    BassmanPaul Gold Supporting Member

    Aug 25, 2007
    Toronto Ontario Canada
    Nah It's the Niacin I have to take that makes me flush! :(

    Thanks for the kind words. Not being able to see makes repairing a crossover board a bit dicey. Do you have a friend who could guide you??
     
  15. LongHairFreak

    LongHairFreak Insert cool nickname? Nobody's given me one yet. Supporting Member

    Aug 7, 2006
    Twin Cities - MN
    Oh sure. It's just a matter of catching my buddies when they have the time to lend. It's a bit ironic, they have the skills (woodworking, electronics, etc.) but their lives are full w/small children, two & three jobs and the like, so have little time/desire to help. I on the other hand have plenty of time (unemployed) w/plenty of desire to do things, but am unable to safely use most power tools and measure w/any sort of detail.