Electrov-Voice EVM12-S

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by Strychnine, Apr 27, 2015.

  1. Strychnine

    Strychnine Member

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    :waveHi ...

    I have some questions about this speaker.

    I own an EVM12-S in perfect state :rotflmao...of RUST , all the steel parts are rusted,not to the core but in surface.
    I can sweep the rust with a towel, or scratch with nails for nasty incrustation... i can reveal the Steel ...so far , so good.
    Magnet top Rusted too...
    Cone removed , still rusty on the gape and so.

    I plan to unscrew the magnet and split the parts to restore this jewel.
    :munch
    Does anyone think that it is possible to resurect this old beast among the living...?
    Or is it better to stick another Magnet section...from an EVM12L for example...?


    Also it should be great if someone can tell me what means the code Under the cone:

    325
    70686 or 70586 .... it is very old and a blurr effect cover the white numbers.

    It should be very helpfull ...because i can't tell the impedance:dunno
     
  2. swiveltung

    swiveltung Member

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    I would be worried about the condition of the Voice coil if the speaker has evidently been that damp. How does it sound now?
     
  3. Strychnine

    Strychnine Member

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    :phonessounds dead flat , zero pulsation ... voice coil shreded, i can't even know the impedance:anon

    I payed 50$ to get an EVM12 -S frame basket... it's what i expected about ...
     
  4. Strychnine

    Strychnine Member

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    I already removed the cone and the spider... rust everywhere....
    I think i 'll go to swap a full "magnet /gape " from a new L version, and buy a "S" recone kit
    It is supposed to be the same size/ deep gape coil / and magnet for all the EVM serie.

    I plan to resurect this one in a TL806 .

    But i need help for identification of my speaker at 100%
     
  5. amphog

    amphog Silver Supporting Member

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    If the magnet assembly is that corroded, you would need to de-mag it, take it apart, clean, reassemble, re-mag.
     
  6. Strychnine

    Strychnine Member

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    Well , in this case it is better to swap the full magnet with a new speaker? ...is it possible?
    ...it is just 3 bolts to remove and that's done?
     
  7. 71strat

    71strat Member

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    Send A Brown Soun a message and ask them. They are Certified OEM EV Repair. Im sure they can 100% restore it.

    They have the cone for the speaker for $95.
     
  8. Strychnine

    Strychnine Member

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    ...the problem is that i live in Spain now =( ... and i plan to send the frame basket to a car tuning Wheel shop for a top coating paint job... i want a custom/custom loudspeaker =) for my home and studio.
    I already have a dual Zakk Wylde in a closed cab for playin'
     
  9. drbob1

    drbob1 Silver Supporting Member

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    That's a big ass ceramic magnet, it's unlikely that its lost a lot of magnetism. If you can take it apart, then reassemble it so that the coil gap is properly centered, that's what I'd do. Then get a recone kit or send it for recone... The cone is what determines the impedance, so just buy the cone (8 or 16 ohms) you want.
     
  10. TimmyP

    TimmyP Member

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    I think removing the pole piece without damage will be nearly impossible. Getting it centered will be even more difficult.
     
  11. zenas

    zenas Member

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    I've taken the pole pieces out of some Fanes. To get them back in centered I used a plastic shim. If I recall I cut the shim out of an 5 quart ice cream pail.

    Those were in a Hiwatt cab two of the four had voice coil rubs. I didn't want to recone so I just figured out how to fix them.
    If I would've had the internet then I would have found out in short order that I couldn't do it.
    They're still working.
     
  12. Strychnine

    Strychnine Member

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    ...that 's what i think drbob1 , so i may swap it soon and try to find a recone kit.

    Also i think , to center the gape ^^ of this big ass magnet i may use a shim as for the coil, doesn't look impossible.
    At least i will need to center the coil,spider and cone at the end....so by the way it's just aiming ....and with shims or so it shouldn't be impossible mission.

    It's what they do in the factory...and i guess without maniac millimetric methodology skill for each 2000000 speakers chain assembled each minute by poor human being (with hangover ^^)

    No? =)
     
    Last edited: Apr 27, 2015
  13. Strychnine

    Strychnine Member

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    :bumpbump zenas ... good job ...that's what i think to do....
     
  14. amphog

    amphog Silver Supporting Member

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    The problem is getting all the debree off the magnetic parts. I have re-center pole pieces, but they were mostly clean.
     
  15. Strychnine

    Strychnine Member

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    :jo ...Yes you are right Amphog... i didn't think about it...even fine sanding/polishing will bring small metal dust ...and with this monstruous magnet :cry:

    I think i 'm gonna swap a new magnet/gap pole/plate from an EVM 12-X ...
     
  16. Strychnine

    Strychnine Member

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    Also i discovered the big difference of quality between my news EVM12 Black Label and this EVM12-S ... just the weight first , the Black Label is very light weight. The metal used for the frame seems weaker ... cheaper aluminium?

    Only the magnet seems to have the same level of quality with the improved venting/plate
     
  17. edgewound

    edgewound Gold Supporting Member

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    Restoring a rusty beast is possible, but as others have said, separating the magnet from the top plate is a REAL challenge if it's not already shifted from a defective glue joint. The big ceramic disc is pretty brittle and might break apart if you start pounding on it. The pieces are bonded together with most likely epoxy.

    If you want to save time, swap a different magnet assembly. the EVM12L and 12S share the same motor. If you relish the challenge to restore it, go for it.


    A good way to derust the metal parts of the magnet assembly is with a sander.

    Good Luck!
     
  18. Strychnine

    Strychnine Member

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    ...well it's what i'm gonna do , the swap from an EVM 12l Classic...New!
    I will shred a new EVM for the glory :bowof ancient solid frame.

    By the way i will also give a phosphoric acid :stir bath to the old magnet...to see if we can do something with.

    First i need a pipe tool to remove the magnet and send the frame to this adress: http://www.absurfacecoating.com/powder/

    They will do a good job , i'm sure.
     

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