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Tube rectifier B+ differences

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  • #31
    And yes I see now that there is much more to planning your B+ voltage than a simple multiplier.

    I'm learning thanks to all of you!


    • #32
      You're not the only one learning from all of this. Thank you for bringing the topic up!
      If it still won't get loud enough, it's probably broken. - Steve Conner
      If the thing works, stop fixing it. - Enzo
      We need more chaos in music, in art... I'm here to make it. - Justin Thomas
      MANY things in human experience can be easily differentiated, yet *impossible* to express as a measurement. - Juan Fahey


      • #33
        Bringing this back, found the tube rectifier txt file i was looking for, of course while looking for something else. Credit goes to the website below
        Five Volt Fullwave Rectifier Tubes - 10 Feb 2017 - Great prices on great tubes!

        Losing the text formatting while trying to paste so i am posting the file.
        Attached Files


        • #34
          Nice mozz the more resources we have the better!
          Very much appreciated!



          • #35
            I personally find graphical illustrations very helpful. It helps me quickly see voltage/current relationships (or others) and better understand operating conditions, particularly when it's nonlinear.
            Here is a nice graphic showing tube rectifier resistance curves, which can be seen in a nice article on tube power supply design here:

            If I have a 50% chance of guessing the right answer, I guess wrong 80% of the time.


            • #36
              Originally posted by Pedro Vecino View Post
              This list can serve as a reference:

              broken link............


              • #37
                Click image for larger version

Name:	Rectifier tube voltage drop chart.GIF
Views:	1
Size:	43.5 KB
ID:	857582

                PS Tube Data cheat sheet.pdf


                • #38
                  Originally posted by Jazz P Bass View Post


                  of course, I was looking for a EZ81


                  • #39
                    I was looking for a EZ81
                    It's all in the tube charts. You need to specify load current and transformer DCRs.
                    - Own Opinions Only -


                    • #40
                      Originally posted by Helmholtz View Post
                      It's all in the tube charts. You need to specify load current and transformer DCRs.
                      Thanks, Helmholtz, but I can't understand the datasheet.

                      If it helps, I'm talking about a guitar amp, PP, 2 ouput tubes el84.....

                      From the data sheet, is the voltage drop Vtr minus Vo?


                      • #41
                        Look at the schematic on page 9. Vtr is the total AC (rms) no-load voltage of the HT winding. Vo is the output DCV (B+). The chart shows how Vo drops with increasing load current. The load current of a 2 x EL84 class AB amp with a B+ of 300V may be around 85mA at idle and 120mA at full power.
                        Last edited by Helmholtz; 04-27-2020, 10:35 PM.
                        - Own Opinions Only -


                        • #42
                          I recently built a pair of Plexi-style Marshall with fixed bias. 3xECC83, 2xEL84 and 2x300VAC. I got approximately 390V with diodes and 360V with EZ81. It fits the graph.
                          Last edited by Pedro Vecino; 04-28-2020, 03:04 PM.