Tiny amp big sound

Discussion in 'Shock Brother's DIY Amps' started by tubeToaster, Sep 20, 2020.

  1. tubeToaster

    tubeToaster TDPRI Member

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    I built a 5F2A into a 5”x7” chassis. The power transformer is a Weber WRVBPT made for a stand alone reverb. With ss rectification it gives me 343 volts on the 6V6 plate. The output transformer is from a Epiphone Valve Junior.
    upload_2020-9-20_10-40-31.jpeg

    upload_2020-9-20_10-41-14.jpeg

    upload_2020-9-20_10-42-39.jpeg

    upload_2020-9-20_10-44-21.jpeg
     
  2. awasson

    awasson Poster Extraordinaire Gold Supporter

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    Nicely done! That’s a really cool little amp.

    Something like this might scratch that itch I have for building a Champ.

    Does that 220k resistor on the 10uF electrolytic get hot? I tend to get OCD when resistors are so close to caps.
     
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  3. tubegeek

    tubegeek Friend of Leo's

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  4. FenderLover

    FenderLover Poster Extraordinaire

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    You didn't use the term, but it's a size that puts the 'micro' into a small build. Cool!

    Does the 470K on the 6V6 grid make it to ground? I don't see a connection there.
     
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  5. tubeToaster

    tubeToaster TDPRI Member

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    There is a small gap between them
     
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  6. tubeToaster

    tubeToaster TDPRI Member

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    Thanks. It is grounded. The ground runs under the board. I changed the 470k to 220k. I felt like it was driving the 6V6 to hard
     
    Last edited: Sep 20, 2020
  7. awasson

    awasson Poster Extraordinaire Gold Supporter

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    I’m putting together a shopping list now.
     
  8. tubeToaster

    tubeToaster TDPRI Member

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    The Weber WRVBPT is only $26 and is 100mA. Works great for a champ build as long as you don’t mind having a diode rectifier
     
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  9. Peegoo

    Peegoo Friend of Leo's

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    That is really beautiful work, tubeToaster.

    The ep-pit-tome of boo-teek!
     
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  10. awasson

    awasson Poster Extraordinaire Gold Supporter

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    I’m happy with diode rectification. I’m looking at their W022905M output transformer. I’ll need a chassis and I’ve got everything else on hand.
     
  11. telemnemonics

    telemnemonics Telefied Ad Free Member

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    Pretty cute!
    Is it quiet?
    Champs are generally lounging in an over sized chassis, they really oughta be more respectful of real estate!
    Look in an old Boogie at the over crowding, why do the little 5 watters get such luxy accommodations?
     
  12. tah1962

    tah1962 Friend of Leo's

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    Nicely done. Very tidy work! Enjoy.
     
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  13. tubeToaster

    tubeToaster TDPRI Member

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    Tha
    Thanks. I’m trying to figure out some kind of cabinet or cover that won’t add to much to the size.
     
  14. SnidelyWhiplash

    SnidelyWhiplash Friend of Leo's

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    I'm sorry, but wouldn't the 220k make the bias hotter??? :confused:
     
  15. tubeToaster

    tubeToaster TDPRI Member

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    It is very quite. And I forgot to add an artificial center tap to the filament wires. But no hum. Maybe the resistor and diode circuit for the LED that is hooked to the filament wires has something to do with it. I don’t know
     
  16. tubeToaster

    tubeToaster TDPRI Member

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    I’m referring to the grid leak resistor. There is 3 470K resistors in that photo. I think the grid leak resistor is the one FenderLover was referring to.
     
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  17. 39martind18

    39martind18 Tele-Afflicted

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    Wooden cigar box?
     
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  18. James Knox

    James Knox Tele-Holic Silver Supporter

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    Really cool!

    I’ve not seen that kind of turret board before. Where do you get that from?
     
  19. Peegoo

    Peegoo Friend of Leo's

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    If I had your username, I'd probably locate one of these and use the shell for a housing. It's already got top vents.

    [​IMG]
     
  20. tubeToaster

    tubeToaster TDPRI Member

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    Antique Electronic Supply
    tubesandmore.com
     
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