Announcement

Collapse
No announcement yet.

Bias select?

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Bias select?

    What does it means the "Bias select EL34 - 6L6" which some of the mesa boogie have?

    Thanks

    [ November 02, 2003, 11:47 AM: Message edited by: angst ]

  • #2
    Re: Bias select?

    An amp is biased for certain power tubes. That amp can easily switch between two different tubes without having to take it to a tech for rebiasing. If you're using EL34 power tubes, then that's what the switch is set for. If switching to 6L6 tubes, then you flip the switch the opposite way to be able to accept those tubes.
    I feel my soul go cold... only the dead are smiling.

    Comment


    • #3
      Re: Bias select?

      So you just change the tubes and turn the switch?

      Thanks

      [ November 02, 2003, 03:12 PM: Message edited by: angst ]

      Comment


      • #4
        Re: Bias select?

        Yep, that's it. Mesa makes it real easy. Some Carvin amps have a selector switch for that, too.
        I feel my soul go cold... only the dead are smiling.

        Comment


        • #5
          Re: Bias select?

          As do some Laney models.
          Sleep!!, That's where I'm a viking!!

          http://www.myspace.com/grindhouseadtheband

          Comment


          • #6
            Re: Bias select?

            I have a crate blue voodoo combo. the manual says you can just swap tubes between 6l6s and el34s. something called auto bias? just doesn't sound right to me. i tried it and liked the sound of the amp better with el34s. maybe in time it will blow up. anyone know how that feature works?

            Comment


            • #7
              Re: Bias select?

              Originally posted by Snatch:
              I have a crate blue voodoo combo. the manual says you can just swap tubes between 6l6s and el34s. something called auto bias? just doesn't sound right to me. i tried it and liked the sound of the amp better with el34s. maybe in time it will blow up. anyone know how that feature works?
              <font size="2" face="Verdana, Helvetica, sans-serif">Mmm, not sure. I have a BV120 head, and I'd love to be able to switch out the 6L6s for some EL34s just to compare the sounds. Maybe I will e-mail my rep.
              Sleep!!, That's where I'm a viking!!

              http://www.myspace.com/grindhouseadtheband

              Comment


              • #8
                Re: Bias select?

                If you have an auto bias feature and the amp's bias is set correctly for it's factory tube type..you should be able to switch between 6L6 and El34 without problems. These amps should also have an adjustable bias pot per output in them in case they go out of tolerance. I would assume the auto bias in the EL34 setting is a higher plate voltage and the 6L6 has a lower plate voltage, but not having taken one apart.. I do not know for certain.

                Check out Pete's (Twisteramps) advice in the top two posts on the Amp/Effects column. It briefly refers to the difference in 6L6 and El34's and auto switching amps like the Mesa DR.

                [ November 04, 2003, 06:20 PM: Message edited by: charvelguy ]

                Comment

                Working...
                X