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Impedance matching transformer

Discussion in 'Shock Brother's DIY Amps' started by BloozeGit, May 7, 2009.

  1. BloozeGit

    BloozeGit Tele-Meister

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    Hey folks,

    I've got an old Rickenbacher Champ-style amp with a 4ohm OT and 4ohm replacement 8" speakers are hard to come by where I live. Can I get away with using a 2:1 transformer with sufficient power rating between the speaker and OT?
     
  2. marshman

    marshman Poster Extraordinaire Silver Supporter

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    The guy that runs 77 (Dennis, I think) told me there's one 'center' where virtually all the tube/stereo techs are located, one of those guys might have a speaker you can use...I'd at least try that out before futzing around with extra trannies. Sorry, I haven't been there in a couple years, and I can't remember where it is.
     
  3. celeste

    celeste Friend of Leo's

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    I would not bother wiht the extra tranny, any reasonable design should handle a 2:1 impedance mismatch without damage. There is easily 2X that amount of range in the speakers own impedance curve. If it really bothers you, then yes, a 2:1 tranny will do the trick just fine, an autoformer works better for this job.
     
  4. BloozeGit

    BloozeGit Tele-Meister

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    Marshman, I think I know where you're talking about but those guys are mainly hi-fi/audiophile techs, they don't have much in the way of guitar amp speakers. I've messed around with other speakers but more often than not they don't sound right.

    Celeste, this being an old amp I want to be on the safe side. I never knew what an autoformer was till you mentioned it :eek:

    Thanks for the replies folks!
     
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