Preamp tubes layout on my OD-100

Discussion in 'Amps and Cabs' started by countandduke, Mar 5, 2006.

  1. countandduke

    countandduke Member

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    I have begun experimenting with different preamp tubes in my OD-100. Can anyone fill me in on the preamp tube layout??

    Thanks,

    Chris
     
  2. Guitar James

    Guitar James Member

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    V1: CH1 1st Gain Stage, CH2 1st Gain Stage
    V2: CH1 2nd and 3rd Stages
    V3: CH2 Boost Stage
    V4: Ch2 Tone Driver
    V5: Effects Loop Buffer
    V6: Phase Inverter

    Hope this helps.
     
  3. countandduke

    countandduke Member

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    Man, helps a lot!!! Thank you sooooo much. I now need to experiment with different tubes but thanks again. This is exactly what I need!!!

    Chris
     
  4. Steve Snider

    Steve Snider Silver Supporting Member

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    You should also try throwing a quad of NOS 7581A power tubes in. Mine sounds a lot better to my ears. More headroom, better definition and better tone all around. Love it. I also replaced the preamp tubes.
     
  5. countandduke

    countandduke Member

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    Thanks Steve, what preamp tubes did you stick in?? My stock Sovtek tubes sound really buzzy to me and I am looking to warm them up a bit.

    Thanks....

    Chris
     
  6. Guitar James

    Guitar James Member

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    Your welcome, I will be picking up my new modded OD100se el34 monster some time in the next couple of weeks. I will let you know what tubes it likes.:RoCkIn
     
  7. Steve Snider

    Steve Snider Silver Supporting Member

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    I used NOS 80's chinese but we just replaced all the Sovteks in my bandmate's od100 SE with a combination of Telefunkens, Mullards and NOS Chinese and his is like butter now, we also used GE 6L6GCs for Power tubes. The amp is spectacular sounding and not buzzy at all.
     
  8. countandduke

    countandduke Member

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    Okay, I am about to reveal my ignorance with tubes types. To my knowledge, the OD-100 that I have comes with 5881's. Are those just another kind of 6L6??? Meaning, you didn't have to do anything different to the amp to replace the 5881's with 6L6's right??

    Thanks.......

    Chris

    I am changing this post because I just learneded myself some info...... www.dougstubes.com teached me......

    Thanks....

    Chris
     
  9. Steve Snider

    Steve Snider Silver Supporting Member

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    Yes just Bias it after you change power tubes to 6L6s or 7581s.
     
  10. countandduke

    countandduke Member

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    Okay, yet another revealing question, how do I do that?? I could do it on my Flexi.......

    Chris
     
  11. Steve Snider

    Steve Snider Silver Supporting Member

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    For the Suhr, I use a weber bias tool that makes it super easy to measure all 4 tubes indedpendantly to make sure the quad is fairly matched and adjust the bias trimmer inside the amp to get to the desired range. My other amps have an external measuring point that I stick a digital voltage meter in and adjust accordingly without going inside or using the Weber Bias thing. Alesandr makes a nice bias tool as well but I am not sure if they have a four headed version.
     
  12. countandduke

    countandduke Member

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    Hmmm, okay, to do this I need to take the chasis out of the amp I take it. I may bring it to someone so I don't electrocute myself.....thanks for the info!!!

    Chris
     
  13. countandduke

    countandduke Member

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    Hmmmm, I just read up on the weber one, does that mean I could put in EL34's ????

    Thanks,

    Chris
     
  14. redplexi

    redplexi Member

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    I just replaced the V4 Pre Amp tube with a new GT 12Ax7M. which is the Mullard reproduction tube. Holy Sh^%, what a Differnce on the Gain side with the Bright switch on. Night and Day Difference.
     
  15. countandduke

    countandduke Member

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    Can you give some description about the differences???

    Thanks,

    Chris
     
  16. redplexi

    redplexi Member

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    With the Bright on, it increases the Gain. But I found it a little too Bright for my Ears. The New Tubes mellowed out the Highs, while Keeping the Gain increase.
     

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