Silverface Champ; possible mods or conversions?

Discussion in 'Amp Tech Center' started by brokenbones, Aug 31, 2020.

  1. brokenbones

    brokenbones Tele-Holic

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    There is a beat to hell SF Champ for sale cheap and I was wondering if this can be converted to at least blackface (or tweed) spec fairly easily? I'm not sure of the year as I haven't contacted the seller.
     
  2. Jon Snell

    Jon Snell Tele-Holic

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    With no sight of condition etc, my piece of string is as long as yours.
     
  3. corliss1

    corliss1 Friend of Leo's Platinum Supporter

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    Yes. To convert to blackface, get it properly serviced and......you're done :D Fender didn't make many changes to the Vibrolux Reverb and smaller amps.

    There are also mods to lift the tone stack to get more of a gainier/tweed sound.
     
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  4. Dacious

    Dacious Poster Extraordinaire

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    There's very little consistent detail change between them.

    If it turns out to have a blown output transformer you could stick a Deluxe output transformer and rewire it into a Champ II and 10" speaker.
     
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  5. Twang Deluxe

    Twang Deluxe Tele-Holic

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    I would not mod a 70s Champ. Some Mods can have a negative effect on the resale value.
    I would use pedals or extension cabinets
     
  6. stantheman

    stantheman Doctor of Teleocity

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    I’d bring it in for a physical get things right is all.
    What You see when You see a Champ is a brush with perfection. The Champ is the one Amplifier You buy and
    keep.
     
  7. Whatizitman

    Whatizitman Friend of Leo's

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    Make a low offer. Buy it. Get it to running to spec. Then decide if you want or need to mod it.

    Champs are champs. They have their own charm. No need to mod them into something else. Unless you really want to.
     
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  8. Wally

    Wally Telefied Ad Free Member

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    SF Champ is a BF Champ as far as the circuit is concerned. The amp will likely need to be recapped and serviced. The tone stack can be lifted to take you into the tweed world....or the tone stack could be modded in other ways to be hotter and more versatile. A ‘beat to hell’ SF Champ at a cheap price is an amp to make into your own, imho.
     
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  9. Javier668

    Javier668 Tele-Meister

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    No needed, i have one and sounds amazing.
    Buy and restore it if you can, put tungsol 6v6 and ready!.
     
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  10. Peegoo

    Peegoo Friend of Leo's

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    I have a 66 blackface and a 72 silverface, and they both sound great. Get it recapped and tested. These record exceptionally well.

    One mod I did to the 72 is I installed a little switch in the back to disable the NFB. It makes the amp sound more "raw" with the NFB loop disabled. The mod is totally reversible back to stock with no extra holes, so the value is unaffected. But I never think about resale value anyway when it comes to guitars and amps. They are made to be played, not worshipped.
     
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  11. Wally

    Wally Telefied Ad Free Member

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    I have found that the biasing is very important in these little amps. No matter what power tube brand you choose, imho the amp will sound its best with a 6V6 that is dissipating at least 16-18 watts.
     
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  12. Karaokesquirrel

    Karaokesquirrel TDPRI Member

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    Tonally one of the best amps ever.
    Compare schematics and you’ll see the BF and SF are identical.
    Conserve it and it will be wonderful.
    The negative feedback cut switch recommended by Peegoo is cool and easy to do.
     
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  13. Boreas

    Boreas Tele-Afflicted Silver Supporter

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    Couldn't agree more - especially if it is an early drip edge SF. If the cab is beyond repair, consider putting the amp into a bigger box with bigger speaker. If the amp has been hacked significantly, do as you wish. Otherwise, repair/restore and respect it.

    Champs and VCs are great recording/practice amps in stock form. This is why they are now commanding significant prices. They are not junk. If this is not what you want, don't buy it at all. Better off building or starting with what you want.
     
  14. King Fan

    King Fan Poster Extraordinaire

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    Good advice on service. Three prong cord, of course. New cap can and other electrolytics would make it more BF *and* SF, since they came with caps in spec. The old resistors may have drifted badly, especially in the 'hot spots.'

    A fairly meaningless CBS mod was to add a 330 pF cap across the 6V6, maybe to deal with oscillations that might arise from CBS lead dress? If it's there, and the amp works, you can leave it even though it's not strictly BF.

    You'll see notes that the SF were often 40-20-20 filter nodes while the BF were 20-20-20, but in fact that's not strictly true. From all I can learn, actual BF often had the first two 20s jumper'd. In any case, use a 4x20 can for the replacement; not only is 40-20-20 'better' sonically, but the 4x20 can is much shorter than the 3x20 can, giving you more speaker / magnet fit options.
     
    Last edited: Aug 31, 2020
  15. brokenbones

    brokenbones Tele-Holic

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    It got sold. It was $120 and sat all weekend. I was honestly surprised no one moved on it until today.
     
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