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New Project: Tweed Princeton...

Discussion in 'Shock Brother's DIY Amps' started by richon, Jul 26, 2009.

  1. richon

    richon Tele-Meister

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    Aplying oak dye to the pine box
    [​IMG]

    After 3 hands, let them dry
    [​IMG]


    Finaly 2 hands of Poliurethane and more hands to come
    [​IMG]


    saludos..
     
  2. richon

    richon Tele-Meister

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    finally, after two weeks of waiting the SPEAKER arrived:

    [​IMG]

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    [​IMG]
     
  3. richon

    richon Tele-Meister

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    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]
     
  4. richon

    richon Tele-Meister

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    [​IMG]




    SPECIAL THANKS to my helpful assistant:
    [​IMG]
     
  5. Travis in BMore

    Travis in BMore Tele-Meister

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    With a helper like that, no wonder it turned out so nice. Cute kid! Thanks for sharing your build!
     
  6. richon

    richon Tele-Meister

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    More Pictures:
    [​IMG]

    testing (with the HEADPHONE tecnik) the right spot to put the OT and not getting some noise from the PT.
    [​IMG]

    meanwhile, the look
    [​IMG]


    maybe tomorrow it will be it first start
     
  7. JohnnyCrash

    JohnnyCrash Doctor of Teleocity

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    Too cool!

    How'd you cut the speaker/baffle hole?

    Where are you mounting the chassis?

    That is the most hand-made, from-scratch, truly DIY build I think I've ever seen!
     
  8. richon

    richon Tele-Meister

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    The Baffle was cut by HAND.... better tha aerobics!!! :D

    Still don't know how to mount the chassis, but sure something DIY.

    More Pictures (Heaters working):
    [​IMG]

    Now it works (kinda!, but it's just 0.000001% from being perfect)
    [​IMG]


    And the DEMO/VIDEO (sorry, it's short but it's midnight and the neighbours would kill me if i keep on playin' )
     
  9. JohnnyCrash

    JohnnyCrash Doctor of Teleocity

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    I can tell you're holding back in that clip... wake the neighbors up in the morning and crank it!!!! HAHA

    Sounds like its got good clank and twang.

    Very cool project. Thank you for sharing that, it makes me want to build another amp!
     
  10. richon

    richon Tele-Meister

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    with the NFB (ON) the amp sound super...

    but when it is (OFF) IT GETS BETTER, but i guess it needs the Tone control for it.
     
  11. richon

    richon Tele-Meister

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    New Picture:
    [​IMG]

    As you can see its modded: I added a TONE control.... so now goes from a 5F1 (Champ) to a 5F2-A (Princeton).... super usefull TONE CONTROL, like it really sofar.

    Besides I played with the first stage Cathode Bypass Cap to test how much changes the GAIN of the amp, and WOW:

    FAT (25uF ON): GAINIER AMP, easy overdrive and no so much Clean Headroom
    NO FAT (no 25UF , just 1,5K resistor alone): CLEANER amp, really nice sound... you get a more controlable amp, it still can overdrive, but way more dinamic

    Now some QUESTIONS:
    1.-it's almoust 99,9% ready, but as I'm really a perfectionist, when the NFB switch is ON or OFF some "Ground Loop KINDA noise" appears very faint. Any ideas where to look at?

    2.- I Found this on TDPRI:
    "To combat the hum in a single ended amp, put a large electro (22uF/450V) between the 6V6 screen and ground - this will rout any underfiltered screen supply hum to ground. Ground the heater center tap (whether a real CT from the NT or the junction of the two 100 ohm Rs) to the high end of the 6V6 cathode.

    Dont forget the screen resistor (470 ohm 3 W)"

    I Don't get the exact place to put the HEATER CT, right now is connected direct to Star-Ground in the Chassis.
     
  12. ThermionicScott

    ThermionicScott Poster Extraordinaire

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    Each to his own, but I don't like the idea of hanging filter capacitors onto the screens *after* a screen resistor. It will hold the screen voltage high when the plate voltage dives, leading to extra screen current. One of the nice things about using screen resistors (the right way) is that they help limit screen current when it gets excessive, and actually make the output tube(s) respond more linearly.

    I would beef up the main power supply electrolytics first. Since you're not using a tube rectifier, you can go ahead and use 47uF (or bigger) for the first two power supply nodes. That should kill the ripple! :D

    BTW, on my 5F2A clone, I didn't notice any difference in noise between hooking the heater CT to ground or to the 6V6 cathode. Either seemed to do the job well.

    - Scott
     
  13. richon

    richon Tele-Meister

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    the Filters are as follows: 47uF + 47uF + 22uF so i think the filtering is fine.

    Maybe I should test a 470R /3W on the grid....

    well , i'll do some modding and testing and get back hear with results (and a VIDEO )
     
  14. richon

    richon Tele-Meister

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    presenting how it will be , with the chassis inside the cabinet, (obviously the long speaker cable is there to test everything, but a new one will be used.

    I installed a new switch (FAT/LIGHT switch) changing the first triode bypass cathode cap from 25uF to 0uf (Princeton 5F2-A/ Champ 5F1) .

    For the moment i think i won't install a switch to avoid the TONE control... i guess it steals really nothing but helps a lot :D


    [​IMG]
     
  15. richon

    richon Tele-Meister

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    I did add a back cover of wood to have it like "half closed back"

    the improvement was very good.....

    waiting on the Speaker to get more loose.... but the back cover was a good thing.
     
  16. fernando

    fernando Tele-Afflicted

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    estoy impresionado, que maravilla!!! :eek:


    What are the settings on the video? It really sounds wonderful!!! At the verge of a smooth overdrive and sparkly at the same time, perfect!!!

    Also, I see you are using current production tubes, they sound good


    It would be great to see the schematic you used, please (I see you used the old 5F2A schem but since you did some mods and looks like you used ss rectifier, etc. ...)


    eres un genio! gracias por compartirlo
     
  17. richon

    richon Tele-Meister

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    Hola Fernando,

    I use the standard 5F2-A schematic... nothing else besides SS rectifier (47uF + 47uF + 22uF filters instead of the little 8uf on schematic, nothing else)

    JJ tubes , nothing NOS...

    (la camara es una CANON powershoot A610, nada especial y graba realmente bien los videos que grabo, siempre suena bien con esa camarita digital de fotos)

    Now i've added some mods:
    -first stage cathode bypass cap with : 25uF or none
    -NFB off or on.

    and that's it.

    saludos alla en Europa!
     
  18. jarmijo

    jarmijo TDPRI Member

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    grande richon!!

    me encantaria poder hacer algo asi
     
  19. podboy3

    podboy3 Tele-Afflicted

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    How come you decided against the tone/no tone switch?
     
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