The Riddle of Tone

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by Danny G, Feb 8, 2006.


  1. Danny G

    Danny G Guest

    So I recently posted some demos on my MySpace page, and was VERY pleased with the tone I had on the recordings.

    I have an '81 JCM800 2203, which I souped up a bit with some mod ideas from Plexi Palace.com. What I did:

    *clipped brite cap
    *replaced 470k/470pf on input w/single 68k (as per Superleads)
    *replaced the box caps with high quality Sozo's
    *strapped a .68uf across the cathode resistor (more mid range snarl, also per Superleads)
    *shield-logo Mullard 12ax7's and 12at7 for V3
    *JJ E34-L power tubes

    I ran the amp full bore (Master and Pre at 7-8) without a dirt pedal in to a Marshall 1960A cab. Needless to say, this thing screams!

    But the question: does the amp sound good because of what I did to it? Or is the vert input JCM800 just a good sounding amp by itself whether I tweaked it or not?

    THAT is the Riddle of Tone. If I don't know the answer, Crom will LAUGH at me! heh

    See for yourself at the link in my sig
     
  2. SteveStrat

    SteveStrat Member

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    Danny,

    Did you spend any time playing the amp before you modified it?

    Steve
     
  3. µ¿ z3®ø™

    µ¿ z3®ø™ Member

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    for the most part i'm not a fan of MV amps.
    but in all my time in studios doing stuff for peeps i'm constantly surprised at the number of JCM800s that are really superb sounding amps in the studios that i work in.
    i do hear that this phenomena is inconsistent from amp to amp, tho'. at least that's what i've HEARD.
     
  4. Danny G

    Danny G Guest

    I used it for about 2 years before I started modifying it.

    Except for the brite cap and .68uf cap I wasn't super scientific about it, I learned all those mods on Plexi Palace and thought I'd give them a shot since I was looking for a more Superlead-ish sound and I wanted to learn more about the inner workings of the 800. Most of the people who tried them were pleased, that was good enough for me.

    I was scientific when I selected preamp tubes. Spent an hour or so swapping and comparing. Might have to do that again now that I'm NOT using a dirt pedal, heh
     
  5. SteveStrat

    SteveStrat Member

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    So how did you like the sound of the amp before you modded it? That's the real question. If you didn't think it sounded good before, and now it sounds great, the mods did a good thing and the stock JCM was crap.

    Personally, I have yet to hear a JCM 800 that sounds bad. Some sound better than others but I can't tell if that's because of the wiring, tubes, speakers, cabinet, guitar...the list gones on and on. Heck on any given night my Mesa will sound great and then next song it will sound like ass.

    Steve
     
  6. Dave C

    Dave C Gold Supporting Member

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    Those are pretty common mods for Jcm 800's, provides a modest gain boost and retains the ability to still clean up with the guitar volume control......I've modded several amps like this , works well.
    Dave C
     

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