Joyo Sweet Baby Tweed Champ clone

Discussion in 'Amp Central Station' started by teza, Jan 12, 2016.

  1. milocj

    milocj Friend of Leo's Ad Free Member

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    That would work, especially with the original style board layout of a tweed Champ. If the Joyo values are true to a Fender it looks like R4 may be the cathode resistor for the input triode of V1 and like that empty capacitor pad might be for a bypass cap.

    Assuming you have the ability to verify the information and trace the bias resistor and the empty capacitor pad traces, something like the cap below might be easier to add. If you like the sound as it is, you could even add the bypass cap to a switch for a "boost". The axial Sprague cap would probably be easier to use if you wanted to add it to a switch on the chassis face.

    http://m.ebay.co.uk/itm/22uF-25V-SA...C22M-OSCON-QTY-10pcs-/141446547868?nav=SEARCH

    I believe there was another thread on here several months ago about these amps except they may have been branded something different from the Thomann website.
     
  2. teza

    teza TDPRI Member

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    Hi,

    Find this on another thread in the forum, if joyo did follow Fender config it looks like C7 would be the spot, I beleive.

    [​IMG]

    Cheers.
     
  3. thatkeithmorris

    thatkeithmorris TDPRI Member

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    I got mine here in the UK a couple of years ago and they were rare then. But they do seem to be available here again under the Juketone brand.

    Mine seems well made and I enjoyed playing it but I went and modded it anyway. It's still my main amp and I love it. The main changes I made were to rewire the rectifier socket to take a proper 6X4, then put in all NOS valves. I also got a bigger, tweed cabinet for it (sourced from Juketone) so I could fit a 10" speaker, a 1980s Fender blue label made by Pyle that I got cheap off eBay.

    It now has a bigger, fuller tweed sound, gritty and responsive clean, louder and with more headroom, especially with a 5751 in the preamp slot. I use it most weeks in my church band and jamming with friends where its volume range is just right.
     
  4. jiri_c

    jiri_c TDPRI Member

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    hello
    that Juketone thing is based on 5F2a circuit, got weird rectifier tube and unlike Joyo 5F1 is handwired. these Princeton clones are made in China by Goldea and sold under several brands.

    got one and love it. even stock! but this particular clone has nothing in common with construction of Joyo (Joyo/Fame champ is PCB, has different rectifier tube, cab is larger and somewhat modern looking).

    but we're talking about two cheapest (and not necessary cheaply made) little tweed amps clones sold nowadays. as i live in old world, i am happy that at least these are available. you guys on the other side of the pond have no idea...
     
    havlma1 likes this.
  5. thatkeithmorris

    thatkeithmorris TDPRI Member

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    Yup, mine is the hand wired Joyo JA-05 Princeton clone (apart from the unusual rectifier as you say). I think Joyo must have dropped it pretty quickly and brought out the other one instead.
     
  6. overlock

    overlock Tele-Afflicted

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    I've been poring over the internal shots of this amp, and I'm struggling to spot the transformers. Are they tiny, or what?
     
  7. Alamo

    Alamo Doctor of Teleocity

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  8. overlock

    overlock Tele-Afflicted

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  9. Alamo

    Alamo Doctor of Teleocity

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    Sounds great to my ears.
    what it is, I have no clue.

    here, I stuck the camera inside.
     

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  10. overlock

    overlock Tele-Afflicted

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    You're too kind, sir. Thank you very much.
     
  11. cocoboudin

    cocoboudin Tele-Holic

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    Here's mine image.jpg image.jpg
     
  12. engineer

    engineer Tele-Meister

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    So,

    I have been GASing for a 50s champ since I came over this sound sample on the interwebz.



    After that I learned that it's a widely studio tool which suits me and all my other lo watt amps.

    But the prices!
    So I have been looking and looking, even checked out a few Silverface Champs...maybe..reissues..still silly money....
    I have also looked into building a kit, which sounds interesting to learn something new. But I can't really bring myself
    since I have not soldered anything. Well, ever. Ok, that one time in tech class in junior high....
    So the most kits I find for 5f1 Champ (in Europe) costs about half of what the "real deal" but it's still too much, I think, when you have to solder and build it yourself.
    Can't say that my work will be all quality.

    So, then I came across the JTA-05.

    Now we're talking! But I'd probably like to replace a few things. First the speaker, maybe tubes, eventually the enclosure (we all want that Tweed).
    But what would you replace in your JTA-05s?

    I'm thinking a Jensen C8R (or maybe a P8R) and some new valves. If I replace the valves would the JTA-05 need to be re-biased?
    Which valves would you like for this?
    I found a Tung-Sol 6V6 reissue and a Groove Tubes GT-5Y3 Rectifier.
    Maybe a tung-sol 12AX7 or a JJ?
     
  13. engineer

    engineer Tele-Meister

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    Hi teza!

    Tell us about your upgrades!

    Does it sound any better?

    Which tubes did you go for?

    Did you change the rectifier type tube?

    Where did you get the cab?
     
  14. teza

    teza TDPRI Member

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    Tube are RCA nos all the way at the moment.
    I like also the Tungsol 6V6 who's a great tube.
    I will probably try also a Mullard ECCC83 to see.
    I think a big improvement will be to change the OT for a better one.

    Speaker is a Weber Alnico signature 8 smooth cone.
     
  15. teza

    teza TDPRI Member

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    Find mine threat where I show pictures of it I gave the link already.

    Cheers.
     
  16. teza

    teza TDPRI Member

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  17. engineer

    engineer Tele-Meister

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  18. AJBaker

    AJBaker Friend of Leo's

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    Although I sent mine back, this thread is making me want to get one again. Has anyone found out if a 10" speaker will fit inside?
     
  19. engineer

    engineer Tele-Meister

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    Good question!

    Of course it can take any size since you have two speaker outputs (4 and 8 ohm). But I assume you want it in the cab?
    So I took a photo for you, where you can see that it should be possible.

    [​IMG]

    The only thing to look out for the the grill mounted on the back of the board that protects the tubes from the power chord (or vice versa). When mounted it is just free of the back of the speaker magnet.
    But it can be removed or maybe "modified-by-dremel" if needed?

    [​IMG]

    BTW, why did you send yours back?
     
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