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Tubes out of order?

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  • Tubes out of order?

    Hi people.
    I have a problem
    I played guitar with my preamp and my power amp Marshall EL34 100/100.
    Suddenly there was a
    Hush and the sound was less loud. I looked through the front window of the amp. A power tube was very bright red, but really more than the others.
    I quickly turned off everything.


    I noticed recently that a fuse broke often, faulting only one side of my dual monoblock amp.

    So let's go and speculate .... What do you think it is? Just the tubes?

  • #2
    Re: Tubes out of order?



    Looks like the 9100 & 9200 run on 5881's.

    FWIW most 5881's made today are just a glorified 6L6.
    Last edited by JMP/HBE; 12-08-2019, 04:46 PM.

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    • #3
      Re: Tubes out of order?

      I think the tubes burned because of a tension problem or something like that.


      I therefore start from the fact that a repair is necessary before the change of the tubes.


      It remains to know which tubes I will mount on this amp.
      El 34 (electro harmonics, dd?), Kt66?

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      • #4
        Re: Tubes out of order?

        edited
        Last edited by JMP/HBE; 12-08-2019, 04:47 PM.

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        • #5
          Re: Tubes out of order?

          Originally posted by Micha View Post
          I think the tubes burned because of a tension problem or something like that.


          I therefore start from the fact that a repair is necessary before the change of the tubes.


          It remains to know which tubes I will mount on this amp.
          El 34 (electro harmonics, dd?), Kt66?
          Wait... are we talking about tubes or strings here?
          "Always remember... all you do in life, comes back to you" - Roy Kahn, formerly of Kamelot, during the intro to "Karma" on their One Cold Winter's Night DVD

          http://www.soundcloud.com/jwflamenco

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          • #6
            Re: Tubes out of order?

            Since the OP obviously knows NOTHING about tube amps, a visit to a competent and experienced tech is in order.
            aka Chris Pile, formerly of Six String Fever

            Comment


            • #7
              Re: Tubes out of order?

              Yep, get it checked out.
              .
              "You should know better by now than to introduce science into a discussion of voodoo."
              .

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              • #8
                Re: Tubes out of order?

                FWIW, the B+ voltage line (plate voltage) is sometimes called the high tension line in tube amps but is unlikely the culprit here, nor is the order of the tubes(?).

                But, while it is possible there is something wrong with the bias circuit, it sounds like there is just a bad tube that red plated and it should be fine to replace the tubes with a rebiasing, which I agree, should be done by a pro.

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                • #9
                  Re: Tubes out of order?

                  Originally posted by Red_Label View Post
                  Wait... are we talking about tubes or strings here?
                  He's probably saying "tension problem" because a common issue with tube amps is the powertube sockets' metal connectors get loose over time
                  and need tensioning.

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                  • #10
                    Re: Tubes out of order?



                    "High Tension" IE; HT fuse ect.

                    This here be HIGH TENSION. 115kv [115,000 VOLTS]
                    Last edited by JMP/HBE; 12-12-2019, 07:57 PM.

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                    • #11
                      Re: Tubes out of order?

                      Originally posted by JMP/HBE View Post


                      "High Tension" IE; HT fuse ect.

                      This here be HIGH TENSION. 115kv [115,000 VOLTS]
                      I'd like to hear an amp that could run the B+ at that voltage.
                      From maybe 100 miles away.

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                      • #12
                        Re: Tubes out of order?

                        Originally posted by Demanic View Post
                        I'd like to hear an amp that could run the B+ at that voltage.
                        From maybe 100 miles away.
                        A coworker is a HAM, he calls my 6L6 and EL34 tubes little baby tubes.
                        Oh no.....


                        Oh Yeah!

                        Comment


                        • #13
                          Re: Tubes out of order?

                          Sounds like a bad power tube. FYI guys I owned a EL 34 Marshall power amp that was bought with my JMP 1 there were indeed a few of those that came with EL 34's.
                          This in fact was recorded in the studio with my JMP 1 El 34 powered 9200 set up in 1994.
                          Guitars
                          Kiesel DC 135, Carvin AE 185, DC 400, DC 127 KOA, DC 127 Quilt Purple, X220C, PRS Custom 24, Washburn USA MG 122 proto , MG 102, MG 120.
                          Amps PRS Archon 50 head, MT 15, Mesa Subway Rocket, DC-5, Carvin X50B Hot Rod Mod head, Zinky 25watt Blue Velvet combo.

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