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5E3 Deluxe - 100 Ohm Res. Hookup ???

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  • 5E3 Deluxe - 100 Ohm Res. Hookup ???

    This is my 1st 5E3 "Build" from Scratch(savalged Power Transformer and Output Transformers), and I am confused as to where to hook up each of the ends of the 100 ohm resistors.???
    I understand that the resistors are "Twisted/Pigtailed" together at one end, and left separate on the other end ???
    On the one "Tweedy Deluxe" Layout I have, shows these two 100 ohm resistors connected to each end of the Green Heater Wires on the Power Transformer, and the other "End"??? ( 1 or 2 ends of these Pigtaileed Resistors ???) it shows with a note: "To 6V6 Cathodes" ??? I thought these went to the 1st 6V6 Heaters ???
    I `m confused as to what and where I attach the "ENDS- 1 or 2" of these 100 ohm resistors ???
    Some Layouts I have seen have these 100 ohm resistors going directly to the "Pilot Lamp".This further confuses me as a 1st time Builder ???
    Are there any 5E3 Build "In Process" Photos I can Visually check My 5E3 Project against ???
    Thanks in advance for any info/help you may be able to provide me with !!!

    Last edited by oldave; 06-05-2006, 03:49 PM. Reason: More Info

  • #2
    If it is one of my kits, you connect the common end of those 100 ohm resistors to the one of the cathodes of the power tubes.
    Both power tube's cathode lugs (lug #8) have a jumper wire on them so they are connected together and then there is a singular wire leading to the eyelet board where the power tube's cathode biasing resistor is.
    In my amps that resistor is 270ohms but 250 is common in other amps too.

    Attached is a couple of pictures I found on my computer... not good but maybe you can see what I mean from these.

    If you do not want to use this method, you can solder the 100 ohm resistors to the pilot lamp's lugs and then connect the other two leads of the resistors together and subsequently to ground.
    Or, if you have a power transformer which has three wires from the 6.3v filament windings, two are green and one of them is probably green with a yellow wtripe.
    This G/y wire is the center tap of the winding and it can be connected to ground or to the ungrounded end of the power tube's cathode biasing resistor.
    Attached Files
    Last edited by Bruce / Mission Amps; 06-05-2006, 05:10 PM.

    Mission Amps
    Denver, CO. 80022


    • #3
      100 ohm Resistor Hook-Up...Thanks Bruce !!!

      Thanks Bruce:
      The Photos and description are just what I needed !!!


      • #4
        Here's another PIX showing the 100 ohm resistors on the other 6V6 tube socket... it makes no difference which tube (even if you use the two filament lugs of the preamp tubes).
        In this application it is one 100 ohm resistor from lug 2 and another 100 ohm resistor from lug 7 to the cathodes of the power tubes (Lug 8).
        Since the cathodes are tied together at lugs 8 the resistors are now connected to the same spot too.
        Or, just think of it as one of two 100 ohm resistors across each green 6.3 filament wire to the cathode biasing resistor of the power tubes.
        Since the connection of these two resistors is in the middle, it forms a virtual center tap for the 6.3v winding.
        Applying a little DC voltage to that spot from the bias voltage derived across the the 6V6's cathode resistor helps keep the hum down a little bit more.
        Not a big deal and a trick that is as old as the hills, found on audio amps from the late 40s through 50s too.
        I didn't invent it.... I just rediscovered it 12 or 15 years ago and started using it again on all my cathode biased amps, even the little 5 watt Soulkicker Jr..
        Attached Files

        Mission Amps
        Denver, CO. 80022