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Champ 12 Owners Club

Discussion in 'Amp Owners Clubs' started by Obsessed, Feb 10, 2013.

  1. Chaz-Keys

    Chaz-Keys TDPRI Member

    4
    Nov 7, 2018
    UK
    Just came across this forum!

    I've had the Champ for about 6 months but mainly use it for keys. It's a red knob in great condition and I've replaced the Chinese 6L6 with a JJ tube. I'm about to look at replacing the 12AX7s but just checking that the existing tubes are the original Chinese ones. So here's some photos. They are badged Fender. Any help greatly appreciated.

    IMG_2374.jpg IMG_2373.jpg
     
    Last edited: Nov 7, 2018
  2. czech-one-2

    czech-one-2 Friend of Leo's

    Oct 3, 2008
    East of you
    Hi, the original tubes in the Champ 12 were USA made, probably GE. Those tubes are Chinese as far as I can tell.
     
  3. Chaz-Keys

    Chaz-Keys TDPRI Member

    4
    Nov 7, 2018
    UK
    Thanks for the info.

    My plan is to replace the valve (V2) that handles the overdrive channel with a JJ 5751.

    Watford Valves (UK) say..... The JJ 5751 is a low gain version of the 12AX7.The valve produces a gain reduction of between 15 to 30 % when compared to a 12AX7 and gives a cleaner sound if used in the first stage. Ideal for those wishing to clean up their amplifiers distorted tone or simply get more clean headroom.

    Thinking this might be a simple solution to tame the overdrive channel on the Champ. I have also been given a 12AX7 which I think is from a 90s Fender Twin. It says USA on the glass but some of the legend has worn off so don't know if it's any good. I've swapped it and it works - I haven't really AB'd properly but sounded OK. Have a look at the photos.

    Is it OK to use 2 different versions in the pre-amp?

    Cheers

    IMG_2382.jpg IMG_2383.jpg
     
    Last edited: Nov 8, 2018
  4. Chaz-Keys

    Chaz-Keys TDPRI Member

    4
    Nov 7, 2018
    UK
    Does anyone have any other recommendations for replacement 12AX7As?
     
  5. Lynxtrap

    Lynxtrap Tele-Holic

    552
    Feb 29, 2016
    EU
    Put the lower gain tube in V1, for two main reasons. The massive distortion is mainly caused by the output from V1 overdriving the first triode of V2, so you probably want to send less gain from V1 into V2. Plus, the other half of V2 affects the reverb (if you use the reverb).

    5751 or any tube with lower gain is worth trying in V1. But it takes a lot to tame that overdrive channel. The risk being you'll end up with a weaker sounding clean channel and a still sh---y sounding OD channel.
    And it won't really increase headroom in the clean channel, as it also will decrease overall volume proportionally.
     
  6. Chaz-Keys

    Chaz-Keys TDPRI Member

    4
    Nov 7, 2018
    UK
    Cheers - I don't want to lose any gain on the clean channel as that's the one I use most of the time. I'll probably just go for a pair Sovtek 12AX7WC.

    Thanks for your input.
     
  7. DaveKS

    DaveKS Friend of Leo's Ad Free Member

    Oct 21, 2013
    KS
    Original tubes in both my Champ12 (orig owner) were not USA made, all were Chinese like ones above, including power tubes.
     
  8. DaveKS

    DaveKS Friend of Leo's Ad Free Member

    Oct 21, 2013
    KS
    I run RCA7025>Sylvania 5751 in mine, been purring along superbly for close to a decade now.

    Of new production stuff I’d put Svetlana 12ax7 (sounds almost like the old RCA) in v1 and TAD 7025wa v2. TAD are about lowest gain 12ax7 made today, closer to a 5751 but sound better than JJ or anybody else’s 5751 made today, the JJ 5751 sounded awful to me.

    If you really want to tame gain on drive channel get a JJ ecc823, it’s a reverse wired 12dw7, 12ax7/12au7 triodes, it’ll knock Gain knobs sensitivity down considerably. The reg JJ 12dw7 (ecc832) 12au7/12ax7 wont work as well.
     
  9. czech-one-2

    czech-one-2 Friend of Leo's

    Oct 3, 2008
    East of you
    Hmm, I guess I got lucky with mine! :)
     
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