Got My JSX Modded

Discussion in 'Gear & Equipment' started by maggotspawn, Nov 21, 2016.

  1. maggotspawn

    maggotspawn SS.org Regular

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    I wanted some more gain on the Crunch channel. After searching the internet, it seemed that a cap, a resistor and the gain pot needed be changed. Turns out just the gain pot needed to be changed from 500k to 1 Meg. Don't need to boost the Crunch channel anymore. I'm happier then a pig in $h!t.
     
  2. vick1000

    vick1000 SS.org Regular

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    So crunch now sounds like ultra?
     
  3. maggotspawn

    maggotspawn SS.org Regular

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    Not really. Still more open sounding and not as compressed as the Ultra channel, just a little more gain.
     
  4. noUser01

    noUser01 Still can't play.

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    This thread is useless until you prove it. ;) Clips?
     
  5. Syphon

    Syphon SS.org Regular

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    Changing the cap probably wouldn't have done much. The pot is a good call since it's not going to mess with the bias of any stage.
     
  6. MetalHead40

    MetalHead40 SS.org Regular

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    Glad your diggin it!

    I had the re-badged Triple XXX II, and could not get on with that amp period. Not sure how close it really is to the JSX, the tech at Peavey said it was only tweaked slightly, but man I hated the tone of that amp.
     
  7. maggotspawn

    maggotspawn SS.org Regular

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    I'll try and record something this weekend.
     
  8. vick1000

    vick1000 SS.org Regular

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    The only thing they "tweaked", was the headshell and chassis cosmetics. They are hard amps to dial in unless you get the right boost out front, and maybe even change the power tubes to something more mid focused and darker. They are brittle with standard 6L6s, and the active EQ is unusual.
     
  9. MetalHead40

    MetalHead40 SS.org Regular

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    Well when I was researching buying it I called Peavey direct and spoke with one of their techs. He told me that there was some minor tweaking done to the circuit. What specifically, I have no idea. Whether that was true or not, I don't know:scratch:

    As for the active eq, yeah I agree they're tough to dial in, but I had it 3 years and got pretty dang familiar with dialing it in. I also tried it with EL34s and 6L6s, cold biased, hot biased, replaced the preamp tubes with a bunch of different cocktails. Ran an MXR 10 band in the loop which helped immensely. Tried it with several guitars and a bunch of different pups. The boost is the only area I did not experiment. I boosted it with a Ts9 as that's what I had. Just was never gonna be an amp I'd like. Moved on to Engl and am completely satisfied.
     
  10. Thanatopsis

    Thanatopsis SS.org Regular

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    I have to disagree with that, I changed C14 from a .001uF to a .0022uF on my Rockmaster preamp and it made a difference which I'm very happy with. I was planning some other mods as well but after doing that I was so happy with it I decided to let it be. I'd love to pick up a second one to play around with more though.
     
  11. maggotspawn

    maggotspawn SS.org Regular

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    Changing the cap along with the resistor had a huge effect. I had like no gain at all on the Crunch and Ultra channels.
     
  12. Syphon

    Syphon SS.org Regular

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    Different amp partner. This one doesn't have such anemic values in the first place. Most of the industy uses .0022nf for pretty much any plate capacitor to start with, so that was definitely a worthy change.
    Yes along with the resistor. It will change the frequencies passed thus the gain at those frequencies but the pot is still the best overall choice. Changing the cathode cap's value or the load cap will just change frequencies passed at max gain, which is already most guitar frequencies to begin with.

    My point is that not much GOOD would have came from changing the cap alone.
     
  13. maggotspawn

    maggotspawn SS.org Regular

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    The point of changing the cap was supposed to be to boost lower frequencies then a stock JSX. More like a XXX.
    That particular mod was wrong to begin with. You can't believe everything you read on the Internet.
     
  14. Syphon

    Syphon SS.org Regular

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    In reference to a single cap changing the JSX to the XXX? No doubt. Satriani loves his cocked wah tone. I wouldn't be surprised if they incorporated that thought process into the output transformer specs as well.
     
  15. maggotspawn

    maggotspawn SS.org Regular

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