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6v6 superlead?

Discussion in 'Shock Brother's DIY Amps' started by JamesAM, Nov 18, 2020.

  1. JamesAM

    JamesAM Tele-Meister

    May 13, 2020
    Virginia, USA
    Hi guys,

    I’m doing some preliminary research into building a low-wattage plexi with 6v6s. most of the 6v6 plexi builds I’ve seen are based around the JTM45 circuit, but I’d like to see whether it’s possible to emulate the crunch of a 1959 superlead with a solid state rectifier, dual lower wattage 6v6 power tubes, and a single 12” greenback speaker. I’m hoping to get about 20 watts out of it to keep the greenback sound. Does an OT exist that will get me the impedance I need to run a single speaker with that circuit?

    I’d like to use an 18 watt cabinet and maybe a bluesbreaker chassis, but I don’t think those are compatible. I’d also like to keep the two channel circuit with jumpering capabilities, so an 18 watt chassis is out.

    could i use one of the hotter 5e3 PTs? I figure that would get me right around 400v on the plates with a ss rectifier- I was thinking about just using one of the copper caps as a rectifier, but I’m not sure if that will tighten the feel enough.

    has anyone tried this before, and did you have to build a custom chassis? Is such a build even possible given the solid state rectifier and OT requirements, or should I stick with a JTM 45 circuit? I’m mostly just looking for someone to say that either this is possible or I’m just an idiot (which is much more likely).

    thanks for any help you can provide!
  2. dogmeat

    dogmeat Friend of Leo's

    Oct 12, 2017
    I built the Hoffman 18w Plexi & like it a lot. I used Classic Tone transformers. B+ is about 400 volts with a SS rectifier, a bit less a 5Y3 tube. the output is 8 ohms & I ran to a Speaker Warehouse ET65. I building a second one adding a 1 tube reverb and will use a greenback. Hoffman has some sound clips on his site. fwiw. I don't think there is any real way to get the cranked plexi sound without being cranked. none the less, I love this amp & so does everyone thats plugged into it
    JamesAM likes this.
  3. Phrygian77

    Phrygian77 Friend of Leo's Gold Supporter

    Apr 30, 2016
    Crawfordville, FL
    A quad 6V6 1959 build is a project I bought parts for at least a couple of years ago. I've got a Super Lead/Bass chassis for it, and ClassicTone 50 watt (1987) iron sitting on the self. I've even had the cans so long now that they may be suspect.

    One thing to think about is that you probably want the preamp voltages to be the same as whatever model & era Marshall your shooting for. Another thing is that the 6V6 don't need as much signal on the grids to drive them. You can deal with that by tweaking the PI and/or lowering the 6V6 the grid leaks.

    Lastly, A single 20-25 watt speaker isn't really enough power handing for a fixed bias pair of 6V6s in class A/B. A G12M-65 would be a safer choice.
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