Cleaning up Vibro champ sound

Discussion in 'Amps and Cabs' started by Rivi, Sep 15, 2008.

  1. Rivi

    Rivi Member

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    I have a 68 Vibro champ that gets dirty way too early,even at 4 its very dirty.I've changed the EH 6v6 out for a Tung Sol and though it helped a little its still way too dirty.I also modded the feedback circuit but that only made it worse.Dirty is cool but not all the time.
     
  2. traynor_garnet

    traynor_garnet Member

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    These simply don't have a lot of headroom. Have you tried a lower gain 12a_7 variant in V1? Have you tried a different speaker (a bigger speaker will project more, making your clean sounds louder)?

    TG
     
  3. Rivi

    Rivi Member

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    I didn'y try a different 12ax but i have tried different speaker combonations.Right now i;m using one Jensen MOD 10-35 and a Vintage Jensen c10 together ,it sounds very nice but dirty all the time gets old after a while.If i play any low notes it really breaks up.I also added a 1k resistor and 50v cap to the 6v6 cathod circuit.It did clean it a little and got rid of the fart sounds but i'd like more please. LOL
     
  4. plygtar

    plygtar Member

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    Trying a 12AT7. They are even lower gain then the AX.
     
  5. Rick1114

    Rick1114 Member

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    Something doesn't sound right - My 66 VC sounds pretty clean up to 8-9. Leo designed these amps to stay clean, because that's what players wanted back then. Maybe something in the amp is not running up to spec?
     
  6. traviswalk

    traviswalk In the Great State Gold Supporting Member

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    My '65 is surely not dirty at 4, I would check that as well.
     
  7. Rivi

    Rivi Member

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    I can't find any trouble with it,its also very loud even at 4 maybe that the trouble?All the tubes are good and everything works fine.Adding the resistor really helped the low fart sound it had when hitting hard on the low e string.I was hoping to stay clean until 6 or so.I'll make a small sound file so you can hear it set at 3 1/2 -4 to see what you think this dist sound is.Sounds to me like a amp turned way high up or the input signal way to high all the time.Is there a mod for the 12AX7 tube circuit like there is for the 6v6 cathod circuit?
     
  8. erksin

    erksin Member

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    I use a 5751 in v1 and swapped out the stock Oxford for a Weber Ceramic Sig 8.

    Mine is uber clean now - won't break up until 7-8 on the volume.
     
  9. Rivi

    Rivi Member

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    I'll try a diff preamp tube but i think i figured out whats going on.The strat i'm using has very hot ceramic pickups in it and the peavey i use has very hot active pickups.I'll bet this is driving the presamp circuit too much.
     
  10. cugel

    cugel Member

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    my sfvc was also very clean and wouldnt give up the dirt until dimed
    i think there is a a problem somewhere, i havent come across anyone who wanted vc to sound cleaner since thats really what they do best
    is the impdedance correct at 4 ohms when you have those two spks connected?
    IMHO compared to a deluxe or an 18 watt marshall these have headroom based on what you get on 4 compared to 10 @ the volume knob
     
  11. Rivi

    Rivi Member

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    Something else very crazy is going on here.I tried hooking 4 ohm and 8 ohm loads to it,even at 3 its distorted and sounds like a amp turned on ten???geez i wonder whats going on?If i hot a open string it has a dirty distorted sound top it.Like i have a dist pedal hooked up but there is none.Could almost discribe it as a buzzing type distortion sound but the amp is compleyely quiet when you don't play.
     
  12. Rivi

    Rivi Member

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    I'm going to try changing out all the tubes before i mess any more,this is quite strange
     
  13. traviswalk

    traviswalk In the Great State Gold Supporting Member

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    Rivi that does sound funky, good luck with your troubleshoot.

    Can we have a sideline discussion to talk about how cool these little amps are??!! I love mine, particularly putting a high quality condenser mic in front of it and record away. Dig it. Especially when the one I found had an owner who didn't know it was outfitted with NOS Mullards and RCA Black Plates....genius.
     
  14. Rivi

    Rivi Member

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    nope changing tubes same thing.It sounds very cool but by the time i'm at 6 its so distorted its useless?????
     
  15. Rivi

    Rivi Member

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    ok i;m completely stumped here,i have some kind of freak problem,the amp is very loud and works ok it just sounds like its on 10 all the time even if its set at 4.Some amp guru gotta know something about this.
     
  16. traviswalk

    traviswalk In the Great State Gold Supporting Member

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    Hmmm...tech time unfortunately it sounds like. Bummer.
     
  17. mbratch

    mbratch Member

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    I've owned a couple and they get grind around 5. I'm very surprised to read that some people have to dime the amp to get overdrive.
     
  18. Rivi

    Rivi Member

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    The best way to discribe the sound is (i know this will sound crazy)but it sounds like a full very cool amp turned up to ten at any volume.What could do such a thing?I don't have any effects hooked up to it.I'm going to make a sound sample maybe someone will know by the sound.
     
  19. Rivi

    Rivi Member

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    I tried making a sound file on the computer but it just doesn't record the sound well enough to do it justice.Imagine the coolest sounding distortion you ever heard,thick crunchy super sustain but it starts at like 3 and by 6 its so thick its hard to hear notes anymore...thats the sound.Before i pay 65 an hr i';m going to order the lower output preamp tube and try that.I just don't think its any really wrong other than too much signal going in.
     
  20. Axekisser

    Axekisser Member

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    Mine's clean till about 6 or 7. It's been fully capped though. Sounds like you need a cap job.
     

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