Lend me a reccommendation?

Discussion in 'Amps and Cabs' started by i am ozymandias, Aug 15, 2008.

  1. i am ozymandias

    i am ozymandias Member

    Messages:
    7
    Joined:
    Jul 31, 2008
    Location:
    Maryland / North Carolina
    A) There is a horrible ringing from my tubes when I hold a power chord out.
    My power tubes ring like crazy (sounds like a broken lightbulb being shaken) whether they're hot or not.
    B) I want to change them because of this and because...
    C) My distortion channel is really saggy/ spongy. I suspect poer tubes will tighten it up.
    D) My preamp tubes are fine, newish, and minimally microphonic.

    Should I change the tubes?

    If so can I just order a matched pair of EL34s? I don't really want to rebias, so how can I ensure that I order the right grade of tubes?
     
  2. Blue Strat

    Blue Strat Member

    Messages:
    30,036
    Joined:
    Aug 2, 2002
    Location:
    Sterling, VA (not far from Washington DC)
    Ordering matched power tubes doesn't insure that they will bias correctly in your amp without making a bias adjustment. The reason we use matched tubes is that there's a lot of variance in a random batch of tubes and two random tubes will not likely match.

    The sound you describe could just as easily be a microphonic preamp tube as a power tube problem.
     
  3. i am ozymandias

    i am ozymandias Member

    Messages:
    7
    Joined:
    Jul 31, 2008
    Location:
    Maryland / North Carolina
    In the event that my power tubes go bad, how do I go about buying the correct grade?
     
  4. rob2001

    rob2001 Member

    Messages:
    16,945
    Joined:
    Jun 16, 2006
    Location:
    Wisconsin

    It's a personal choice really. First you determine what power tubes you have, (el 34's, 6550's etc..) and research your options for that type of tube. Some are willing to spend big dollars on killer tubes while others are happy with good, standard tubes.

    I'd check Blue strats web page. Lots of valuble info and also a top notch vendor.

    With new power tubes it's pretty important to bias them correctly. You should be able to find a good local tech to bias to the correct voltages. Too hot or cold will likely result in either poor performance or shortened tube life.
     
  5. drbob1

    drbob1 Silver Supporting Member

    Messages:
    22,142
    Joined:
    Aug 9, 2004
    The whole concept of "ranges" or "hardness" for tubes is sort of a marketing thing started by Mesa and Groove Tubes. The idea being that if you bias your amp for a particular response from tubes, and replace them with tubes with the same rating, you don't have to bias. It's a workable plan in most cases, but to start you're going to need to have the amp properly biased for at least one set of tubes. You can easily do it yourself, BUT there's deadly voltages in tube amps and if you're not pretty comfortable (and responsible) dealing with those, pay someone the $30 it'll cost to get it biased. If you buy your tubes from Lord Valve, Blue Strat, Groove Tubes or anyone that tests and rates, you'll be able to get tubes in the future with the same rating (although most of us would still recommend biasing when you change tubes).
     
  6. Blue Strat

    Blue Strat Member

    Messages:
    30,036
    Joined:
    Aug 2, 2002
    Location:
    Sterling, VA (not far from Washington DC)
    Excellent explanation.
     
  7. Gas-man

    Gas-man Unrepentant Massaganist

    Messages:
    18,653
    Joined:
    Feb 28, 2006
    Location:
    Dude Ranch Above The Sea
    So if an amp is not biased correctly it can make the ringing sounds that are described above?
     

Share This Page