Low Wattage "kit" build - need ideas

Discussion in 'Shock Brother's DIY Amps' started by Lavely, Dec 28, 2020.

  1. Lavely

    Lavely TDPRI Member

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    I'm pretty new to building, finishing a 5E3 now (see thread), starting to plan my next build. I would love something like an Emery Superbaby or Microbaby...I am seeking a very "minimalist" or "pure" tube circuit to start with that allows tubes to shine, looking for a big, pure, round clean tone, and the ability to drive the tubes to overdrive at reasonable levels. I really want the option to swap preamp, power amp and recto tubes to use oddballs I have sitting around. Then, I may start doing some mods after that. I have plenty of big amps, this one would be my Tube Overdrive model.

    I also would like to build something that has been completely spec'd out by someone, including the ability for me to simply buy a chassis and circuit board that will work. Not necessarily laziness on my part (though I suppose that could be argued!), just trying to limit what I'm getting into in terms of time...for example, I'm going to have a ball building the 5E3 and trying a few mods to change the sound. But, I really don't want to have to figure out how to cut a metal chassis or construct a turret board. It was very easy to buy a chassis, order transformers & parts from a list, etc.

    I have done a couple hours of research, and most of the references I find are to relatively "dead" projects - Firefly, Gilmore - that used to get close to what I'm seeking. Meaning, they are no longer available as kits. OR lower wattage amps that use 12AU7 or smaller oddball tubes as the power section. Probably the best I see now are Rob's MicroDeluxe, MicroChamp and MicroBassman - they are all spec'd out, and it looks like I can send a software file to someone to have that made...unsure yet on the board itself (just haven't gotten that far).

    Am I missing anything obvious, or does anyone have links to small, low wattage "kits" that are available? The more I look, it seems like perhaps a Champ circuit is the way to start, whether using Rob's MicroChamp or not, then modding from there. 5W is more than I want, but perhaps a MV or attenuator would be useful and provide what I'm seeking.
     
  2. Peegoo

    Peegoo Poster Extraordinaire

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    Mojotone and Weber sell kits. The components are pretty good in these.
     
  3. Lavely

    Lavely TDPRI Member

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    Weber's site is down until next week...MojoTone has as 12BH7 power tube and solid state rectification. So, Mojo doesn't really work, Weber might.
     
  4. Muzzy

    Muzzy TDPRI Member

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    I believe Trinity has some low wattage kits.
     
  5. Lavely

    Lavely TDPRI Member

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    Just looking at Trinity now...the Tramp is 6W (too much) and solid state rectified. The Triton allows 6V6/6L6 (not sure about other tubes), but it is also 5+ watts. Would really like more tube choices, and perhaps I could add a MV to that circuit (or an attenuator)?
     
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  6. Asmith

    Asmith Friend of Leo's

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    The current draw on a low wattage (1 wattish) amp doesn't draw enough current to produce voltage sag on a valve rectified amp so I would advise you don't let the rectifier type limit your options.
     
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  7. Lavely

    Lavely TDPRI Member

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    If too low wattage for the tube recto to matter, the Emery Microbaby (tube recto, 1-2W) concept/design is kind of silly to use the tube recto?

    I love "sag" on bigger amps...should I be thinking about a Champ with a MV or attenuator? The nice thing about Champs is you can get a kit very easily, then tweak.
    Would it be possible to tweak a Champ circuit so it could take different types of power tubes instead of just 6V6? I'm not technical enough to understand how this is possible, would need a circuit link that I could add into the Champ design.
     
  8. King Fan

    King Fan Poster Extraordinaire Ad Free Member

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    Unless someone knows a micro amp kit (not my area) I might guess Rob's plans are your best bet. If he has a file you can send to Doug Hoffman for a custom board, that's one problem solved. If he has clear obvious specs for OT and PT, that's two more. If you can build it in an existing chassis (VibroChamp? PR?) that's the big four out of the way.
     
    Last edited: Dec 29, 2020
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  9. andicniko

    andicniko TDPRI Member

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    I think Rob's plans are your best bet. While it's not a kit, he does offer a file to send to Doug Hoffman for the board. Also it's pretty straightforward to have a steel chassis laser cut and folded.

    To give you an idea, see the picture below for one I've just had done for $90 NZD for a deluxe micro (quite chunky 1.5mm stainless steel).

    This took about an hour to draw up on LibreCAD, and I'm sure folks in the USA could get a much better price as these services aren't all that common in NZ. The big upside is you can have exactly what you want made with minimal effort on your part, you just need all the component dimensions and a little thinking time. But it's not a kit sorry.

    About to assemble mine, everything fits so far...
     

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  10. Mark the Moose

    Mark the Moose Tele-Afflicted

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    I would add that Hoffman already has the Blackvibe eyelet board for purchase on his site...no upload or customization required.

    https://hoffmanamps.com/MyStore/per...hispage=MiscEyeletBoard.htm&ORDER_ID=!ORDERID!
     
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  11. cometazzi

    cometazzi Tele-Afflicted Silver Supporter

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    FYI, there's a guy on eBay with the username "moddjobs" that makes boards for Rob's Micro projects. Last year I bought a Micro 5E3 eyelet board from him. Like Hoffman he is open to custom anything.

    I never actually used the eyelet board, as I decided to build a full-blown 5E3 instead (after this first Champ), but it looks as good as any eyelet board I've seen.
     
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  12. Lavely

    Lavely TDPRI Member

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    @cometazzi - Can't find that seller on Ebay - wait, found it under "moddjobbs" - thanks for the heads-up!
     
  13. Wallaby

    Wallaby Friend of Leo's

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    I've been intrigued by the Trinity kits multiple times, they seem like very "deluxe" kits to me, and I like the original designs.

    That being said, I've never built an amp. Maybe someday!
     
  14. VintageSG

    VintageSG Friend of Leo's Ad Free Member

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  15. cometazzi

    cometazzi Tele-Afflicted Silver Supporter

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    Whoops! Sorry about the lost b!
     
  16. Lavely

    Lavely TDPRI Member

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    The TubeTown amp doesn't look much different than US-based models, it also doesn't allow tube swapping. Musikding doesn't ship outside the EU. Thanks anyway on those!

    I'll do some searching VVR, which I keep reading about. Maybe a Champ with that gets me MOST of what I want, other than tube swapping?
     
  17. dan40

    dan40 Friend of Leo's

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  18. dan40

    dan40 Friend of Leo's

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    With the right PT and OT, you can swap in a few different power tube types in a 5f1. Do not try this with the standard transformers though. Many tubes require extra current that the stock 5f1 PT cannot provide.
     
  19. Nickfl

    Nickfl Friend of Leo's

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    What tubes do you want to be able to swap between? You understand that you are going to be limited there because the tubes need to have identical or nearly identical pinouts?
     
  20. Lavely

    Lavely TDPRI Member

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    Well, the Emery allows EL34, 6L6, 6V6 power tubes - basically anything with the same pin configuration. Also, recto tubes are swappable (again, with same pins). What would technically be necessary for this? Bear in mind, it utilizes a single output tube.
     
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