New 6l6 tube problems

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by spyrotheleo, Sep 12, 2006.

  1. spyrotheleo

    spyrotheleo Member

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    I got a pair of groove tube 6l6s and I put them in my amp with two new 12ax7 preamp tubes(or whatever they are) and the 6l6s don't sound all that good. Kind of harsh sounding and muddy. I put back in the electroharmonic el34s and they sound alot better. Is the 6l6s just bad or something? And sence I just bought them si there a way to get a replacement or my money back? Thanks
     
  2. slider313

    slider313 Silver Supporting Member

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    Well if you replaced EL34's with 6L6's it sure isn't going to sound good without adjusting the bias.
     
  3. tonezoneonline

    tonezoneonline Member

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    You did not mention what kind of amp you have.The EL34's are connected internally different than a 6L6.They are not interchangable in all amps without some rewiring.
     
  4. spyrotheleo

    spyrotheleo Member

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    I have a thd bivalve.
     
  5. donnyjaguar

    donnyjaguar Member

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    From their site:

    The BiValve is a single-ended pure Class A design. However, it has two output valves which are wired in parallel and combined through a special output transformer to deliver up to around 30 watts. You can use almost any output valve you like without touching any kind of bias adjustment, and get this: in the BiValve you can use them in any combination as well. Combined with the capability to take almost any preamp valve, this makes the BiValve even more of an amp-tweakers dream than its predecessor. Because there's such a wide range of tone available you your style.

    Maybe the 6L6 tubes just don't sound as good to your ears as the EL34s?

    If this is truly a class A single ended design there is probably no feedback so you really are at the mercy of the output tube(s) performance.

    Now, I could say that you've proven to me again that EL34 tubes do sound better than 6L6s. :)

    DJ
     
  6. spyrotheleo

    spyrotheleo Member

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    The 6l6s to my ear are just too muddy to do power chords and too harsh for anything else. I guess I could try putting a el34 and 6l6 to see what that sounds like lol
     
  7. Swarty

    Swarty Member

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    The amp by design is going to favor some tubes over others. Some tubes are going to land right in the heart of their operating parameters, others are going to be on the fringes or maybe even out. If it were truely a tweaker's dream it would have some sort of plate current adjustment (a 6 way rotary switch with various cathode resistors?), switchable screen grid resistors and switchable output impedence.
     
  8. spyrotheleo

    spyrotheleo Member

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    I don't know if the low v and high v switch is sort of like the plate current adjustment you were talking about. But it makes it so you can use some tubes that high v is too much for.
     
  9. Voxy Foxy

    Voxy Foxy Member

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    6L6's are the worst tube ever. That's why. :AOK

    (Boy am I gonna get it...)
     
  10. spyrotheleo

    spyrotheleo Member

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    well atleast I know its not my amp lol/
     

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