JVM C83 Mod

Discussion in 'Amps and Cabs' started by The Pup, Feb 5, 2008.


  1. The Pup

    The Pup Supporting Member

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    Did the mod.

    ...and I like it.

    Getting the chassis to let go of the main board was a bit of a chore (I choose to desolder the little blue C83 cap and completely remove it). All-in-all, 45 minutes including a bias check and head shell swap.

    I recommend taking it to your tech if you are not amp electronics savvy.

    I did not record anything...someone else can do that.

    The mod seemed to do the following:
    - Smoothed out OD-1/-2 (I think).
    - Remapped the gain on OD-1/-2 which now allows you to turn-up the gain in OD-1/-2 to get a fuller sound...without the hyper gain and squeal to go with it.

    I don't trust my ears to say any more...although I seem to like the sound of each gain-controlled channel better. However, this could be my mind playing tricks on me.

    I like it...and I'm staying with it.

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    I haven't spent much time with it...I'll report more if there's anything else worth mentioning.

    P.S. Although an unexpected gift from my wife...the JVM is one of my favorite amps ever (I've got 27 amps in the stable as of today).

    What a woman!

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  2. * velcro-fly *

    * velcro-fly * Supporting Member

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    Glad it worked out for you and the cab looks killer :AOK



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    Very very cool..I'm guessing you hooked up with Gooma (Brad) for that shell? Brad is as good a bloke you could ever hope to deal with....

    Did you see this one he did for Digi-jams?

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    Both are a 500% improvement :BEER
     
  3. The Pup

    The Pup Supporting Member

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  4. kanderson

    kanderson Supporting Member

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    Okay...since nobody else has asked... How'd you get your effect pedals to levitate by your cab? :D
     
  5. Purplexi

    Purplexi Member

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    Uhhh..yeah. Pup? You are so, in the zone dude. What a set up! Now wait, who did your headbox?? jeez my head almost fell off when I saw that! Just beautiful... JVM, twin Vox, Fender, Eventide. I'm saving this page to wallpaper..
     
  6. dumeril7

    dumeril7 Member

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    That head cabinet is really cool!

    D7
     
  7. Plexihacker

    Plexihacker Member

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    Looks great! :dude

    Regarding the C83 mod, how much gain did you lose afterwards. For example, if the gain is fully clockwise now, where would the equivalent gain knob be set on the amp sans mod?

    I am interested in the mod but am afraid to lose too much gain. One of the appealing features of the JVM to me is the fact that I don't ever feel the need to use an OD or distortion pedal.
     
  8. digital jams

    digital jams Member

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    So you like my wood huh??? :crazyguy

    LOL......Taking pics tonight and review....short is that the shell is very impressive and I could not be any happier.

    About the mod...still on the fence about it and may remove one leg and tape to try it out.
     
  9. The Pup

    The Pup Supporting Member

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    What was once 4/10 is now approximately 6.5/10 (which means fuller sound at lower gain-levels)...there is more gain than I will ever need. Cranking the gain even further brings on a exponential amount of terror and horror...no worries. :Devil
     
  10. The Pup

    The Pup Supporting Member

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    "L" brackets attached to the cab's handle screws. The effect pedals can be removed and used on the floor very easily or set at arm-level for fine tweaking. I fashioned a sort of hangar our of a piece of wire I found in the garage...like this:

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