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5E3x2 ---> xmfrms for all-6L6?

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  • 5E3x2 ---> xmfrms for all-6L6?

    I'm going to turn my 5E3x2 an all-6L6 monster. I had a Mission Amps 5E3 I modded for 6L6s about five yrs ago, with great results. My Weber 5E3x2 just isn't loud enough.

    My question: What are good OPTs and PTs for this? I don't want to spend too much dough. I'm looking at Twin-type trannies, but wondering if anybody has any other ideas.

    thx,
    cg

  • #2
    If it's not loud enough, your band is playng to loud!!!

    Seriusly, I've been playing my version of a 5E3X2 for several months now at all gig's and jams I've been at. I almost always have a Weber Load dump engaged to scrub off at least a couple of db's. This at good sized clubs and with quite a few other players. Running it straight with no attenuation it's too loud. I don't know where you're playing at, but if your band is exceeding these volumes I don't know you're doing it without complaints.

    I've got an outdoor gig coming up next month, I may take the Super Reverb out for that though. I've never had an occaison where the SR wasn't loud enough.

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    • #3
      Originally posted by hasserl View Post
      If it's not loud enough, your band is playng to loud!!!
      I do indeed need the volume. My question was technical, not aesthetic, bro! Just wondering whether there was any better/cheaper alternatives to dropping replacement Twin OPT and PT into the chassis.

      As it turns out, I have power and output trannies from an old 6 x 6L6 PA head that should be up to the task.

      The two Weber 12"s ought to be able to handle the 80-100 watts, but if anybody knows of any other potential pitfalls, I'd be happy to take the advice.

      Comment


      • #4
        Originally posted by Chris G View Post
        I do indeed need the volume. My question was technical, not aesthetic, bro! Just wondering whether there was any better/cheaper alternatives to dropping replacement Twin OPT and PT into the chassis.

        As it turns out, I have power and output trannies from an old 6 x 6L6 PA head that should be up to the task.

        The two Weber 12"s ought to be able to handle the 80-100 watts, but if anybody knows of any other potential pitfalls, I'd be happy to take the advice.
        When I first did those amps and before I turned Weber on to it, I used a reissue, TMI OT for a silverface, 45 watt Super Reverb with my 200ma Heyboer PT that also had a 320vac secondary.
        With four 6V6s it made about 32-34 watts and fairly clean at that power output.
        With a bigger PT and OT you should be able to double that.
        now with that said... did you build it from a Weber kit that used an inexpensive 25 watt, Chinese OT that is actually based on a fixed bias Pro Reverb?
        That would be the first thing I would change and use a reissue one for a Super Reverb so you can get the 4 ohm tap... followed by each set of power tubes having a 250 ohm 10 watt cathode biasing resistor with a couple 47uF to 100uF@100v bypass caps and a couple Celestion Vintage 30s.
        If that doesn't get it... WOW!... dump the cathode biasing and go with fixed bias with all four 6V6s idling at about 9-10 watts each into the 50 watt OT.
        If that isn't enough then you keep the fixed bias and use two 6550s with solid state rectifiers and keep the SF Super Reverb 50 watt OT.
        After all that and it isn't loud enough... then it's time for you to go into your own development of a 80 to 100 watt version.
        Bruce

        Mission Amps
        Denver, CO. 80022
        www.missionamps.com
        303-955-2412

        Comment


        • #5
          Originally posted by Bruce / Mission Amps View Post
          When I first did those amps and before I turned Weber on to it, I used a reissue, TMI OT for a silverface, 45 watt Super Reverb with my 200ma Heyboer PT that also had a 320vac secondary.
          With four 6V6s it made about 32-34 watts and fairly clean at that power output.
          With a bigger PT and OT you should be able to double that.
          now with that said... did you build it from a Weber kit that used an inexpensive 25 watt, Chinese OT that is actually based on a fixed bias Pro Reverb?
          That would be the first thing I would change and use a reissue one for a Super Reverb so you can get the 4 ohm tap... followed by each set of power tubes having a 250 ohm 10 watt cathode biasing resistor with a couple 47uF to 100uF@100v bypass caps and a couple Celestion Vintage 30s.
          If that doesn't get it... WOW!... dump the cathode biasing and go with fixed bias with all four 6V6s idling at about 9-10 watts each into the 50 watt OT.
          If that isn't enough then you keep the fixed bias and use two 6550s with solid state rectifiers and keep the SF Super Reverb 50 watt OT.
          After all that and it isn't loud enough... then it's time for you to go into your own development of a 80 to 100 watt version.
          The Weber kit I have was a a stock 5E3x2 from 2006, using these:
          W404248 OT = 4K into 2/4/8R, rated for 40W.
          W022798 PT = 360-0-360 @ 200 mA.

          I'm afraid ain't neither one of these is gonna give me what I need. I'm only getting about 32-33 watts out of the 4x6V6 setup in there now, and it's just not enough for what I do.

          The xfrmrs I have are from an old Bogen PA that ran 6x6L6, plus two 5U4s and some preamp tubes. I think they'll be up to the job. Mounting them will be interesting, but I think I can shoehorn them in there somehow.

          Looks like I'm gonna have a whole new amp by the time I'm done: a 5E3 preamp section grafted onto a 4x6L6 power section.

          Comment


          • #6
            The power you guys have mentioned is spot on, I measured mine at 32 watts clean.

            You'll want to make sure the impedance ratio of the OT gives you the right primary load with your 4 ohm speakers. Other than that, the 6L6's will not be driven as hard by the 5E3 preamp as the 6v6's are, you won't get the same power tube distortion out of it.

            Just curious, why is it you need the extra power? Where are you playing?

            Comment


            • #7
              Originally posted by hasserl View Post
              The power you guys have mentioned is spot on, I measured mine at 32 watts clean.

              You'll want to make sure the impedance ratio of the OT gives you the right primary load with your 4 ohm speakers. Other than that, the 6L6's will not be driven as hard by the 5E3 preamp as the 6v6's are, you won't get the same power tube distortion out of it.

              Just curious, why is it you need the extra power? Where are you playing?
              I figure an OT for 6x6L6 is close enough for 4x6L6. At least I know it won't melt down. I'll measure and mess around with the 2/4/8 ohm taps to get the best sound.

              I need the extra oomph because I'm playing rooms that need it. Also I like sound of the 6L6s in this amp.

              Comment

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