Tech guys - 2203 Master Volume improvements?

Discussion in 'Amps and Cabs' started by worlez, Aug 30, 2005.

  1. worlez

    worlez Member

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    Ok, so I've got my 2203 in the house, which I'm planning to mod a bit. I've already snipped the two treble peaking caps on the input, which has darkened it nicely, but I know there are tweaks that can be made to the Master volume to make it sound better at lower levels. I'd also like to thicken things up slightly and warm it up - I'm always REALLY impressed at how thick the Mojave amps sound, and I'd like to get that sort of vibe.

    I have a couple of mods courtesy of Olaf (from HC) that include MV tweaks, as well as tightening of the bass and smoothing of the highs, but I'd like to get more ideas.

    Cheers

    Al
     
  2. TimD

    TimD Member

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    I'm a bit curious about these treble caps that you have snipped, please tell me more.
    I have a late 70's JMP MKII 50 watter that could use the highs tamed. It's a little bright.

    Thx
    Tim
     
  3. scottosan

    scottosan Supporting Member

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    It just really depends how far you want to take it. You can go from mild to wild. My prototype is based of a 2203/2204 layout but with 14 component changes/additions. You could start by lowering your 10k cathode resistor off of V1 to 4.7k. Another is to change your 220k bais feeder resistors to 150k. This will brown out your sound a bit giving a touch more gain and increase you power tube life a bit (a rebias would be necessary afterwords) It is highly tweekable. An 800 can be modded to get as much gain as the clips I did in the following link without adding any preamp tubes. Again its all up to how much you want to do.

    http://www.thegearpage.net/board/showthread.php?s=&threadid=99218
     
  4. scottosan

    scottosan Supporting Member

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    If its a non master volume or master volume JMP?
     
  5. worlez

    worlez Member

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    Tell me more...

    More gain isn't a huge priority - a stock 800, cranked, has the right amount of gain for me. I just want to fatten things up, make them smoother, sweeter and thicker, ESPECIALLY at lower volumes. I'm a huge fan of the Mojave Coyote/Scorpion/Peacemake clips I've heard - they are so thick and rich and warm.

    Wanna tell me more about your Marshall, scottosan? I rembmer hearing your first clip and thinking it sounded ace.

    Cheers mate :)

    Al
     
  6. TimD

    TimD Member

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    Oops, guess I forgot that minor detail. Mine is a MV.
    I'd love to tame the brightness. I'm all for some sweet highs but this is a tad bit shrill. I have to keep the presence and treble @ 9:00 or below.
     
  7. worlez

    worlez Member

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  8. el34power

    el34power Member

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    What kind of speakers are you all using....Good thing to check before you start chopping off the Marshall...
     
  9. worlez

    worlez Member

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    Im using Gweenbacks in mine. Brightness isn't too much of an issue - its more that I want to thicken up the midrange and top end, make everything gel together.

    Al
     
  10. el34power

    el34power Member

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    FWIW i have 2 greens and 2 red fangs in my 4x12... Very nice match IMO
     
  11. TimD

    TimD Member

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    I'm using the stock celestion GT 75's that came in my 1936 cab. It's an ok cab and I don't really want to change it right now, but I would be open to spkr suggestions.
    I currently play in a band that does a tone of Allman Bros, Mule, Hendrix and the like.
    My guitars are several McCarty's and I've a pretty good tone happening but just need a bit of help with the amp/spkrs.

    Tim
     
  12. mmorse

    mmorse Member

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    Unclemeet, I have an '82 MV 50 watter. Basically the same amp as yours. Mine can be really dark sounding when cranked. I have to run the treble and presence up or it gets muddy. I have SED winged C power tubes. They are rather dark. Plus I think your 75s might be an issue. A change to greenbacks, g12h30s or v30s would help quite a bit. My '82 sounds great through my Avatar 212 with a G12h30/greenback combo. Great tone for the type of music you play. I play the same type. I'm always looking for the classic southern rock type of tone.

    I also have a 2550 Jubilee head but that sounds best with a G12h30/V30 combo. That head is a little brighter and thinner and the V30 through the 212 fills it out better than the greenback. My 212 is semi open back. IMO, Greenies sound fuller in a closed back cabinet.

    I run my '82 through 3 greenies and a V30 in my 412 and I have to goose the treble when I crank it or it sounds too muffled. I play a '73 LP goldtop with an old Dimarzio SD pup that puts out 13.5 k. I can get real close to Allmans tone with my LP and Skynryd tone with my Strat. Full and thick, not bright at all. In fact, if I'm not careful, not bright enough.
     
  13. worlez

    worlez Member

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  14. Roccaforte Amps

    Roccaforte Amps Member

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    Cutting down the bias feed resistors does not increase
    gain, it reduces it. Doug
     
  15. Mastervolume

    Mastervolume Member

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    I would change the neg feed back from 100K to 56K.

    This will take out some of the in your faceness of the amp and give the tone more of a plexi vibe.
     

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