Impedance switch or two jacks?

Discussion in 'Shock Brother's DIY Amps' started by Mark the Moose, Mar 15, 2019 at 8:26 AM.

  1. Mark the Moose

    Mark the Moose Tele-Meister

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    Im going to swap my 8 ohm OT for a 4/8 version so I can run a two-speaker configuration without buying new speakers...I have several 8 ohm speakers on the shelf. Any reason I would put the outputs on a toggle vs adding a second speaker jack? Or both?
     
  2. bblumentritt

    bblumentritt Tele-Afflicted Platinum Supporter

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    I'm a bit unclear on the concept. Are you planning on running both the 4Ω and 8Ω speaker outputs at the same time? Or are you running two 8Ω speakers in a parallel 4Ω configuration?
     
  3. Wyatt

    Wyatt Tele-Afflicted

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    I do what Fender does on the Hot Rod Deluxe and use a transfer jack on the EXT Speaker jack.

    When I plug into the Main Speaker jack, it's connected to the 8-ohm tap on my Vibroclone (NC on the transfer jack). When I plug into the Ext Speaker jack, the jack switches BOTH jacks to the 4-ohm tap (NO on the transfer jack).

    This lets me run an internal 8-ohm speaker, plus add a 8-ohm extension cab if needed (never is) and keep the load matched. Since it's a combo, and I always use the 8-ohm internal speaker, I still use a shunting jack for the Main Speaker jack to protect the OT.
     
  4. Mark the Moose

    Mark the Moose Tele-Meister

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    I currently run a single 8 ohm speaker. I’m building a 2x10 cab and will use two 8-ohm speakers in parallel. Sometimes I may plug into an 8ohm sometimes a 4ohm...never both. My last amp had different speaker jacks for each impedance level and a selector switch. I’ve also seen it done with just speaker jacks and no switch or one speaker jack and a switch. Just wondering what the best practice is.
     
  5. Wyatt

    Wyatt Tele-Afflicted

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    Whatever works best for you. Dedicated jacks per tap; impedance switch; or a jack switching arrangement (like I posted above) all work well and are professional approaches. None are idiot-proof. A careless user can still plug into the wring jack or set the impedance switch incorrectly.
     
  6. King Fan

    King Fan Friend of Leo's Ad Free Member

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    Wyatt is totally right of course. Still, I just said this in another thread with the same question: “I recall guys talking in an ancient thread here about how multiple jacks made it too easy to forget to plug in the speaker when you changed cabs. Worse than forgetting to flip a switch...”


    Sent from my iPad using Tapatalk
     
  7. sds1

    sds1 Tele-Holic

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    Yeah man, really any options presented here are fine in a best-practices context. Whatever seems most intuitive to you.

    Two jacks and a switch would be most versatile.
     
  8. Mark the Moose

    Mark the Moose Tele-Meister

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    Thanks for the input, folks, much appreciated.
     
  9. svMike

    svMike TDPRI Member

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    Question for folks that have experience wiring multi-tap OT, is it possible to use all the outputs at the same time?

    The OT I am planning to use on my 5f1 build has outputs tor 3.2 / 8 / 16 ohms.
    Is it possible to use them all or two if them at the same time?
     
  10. Mark the Moose

    Mark the Moose Tele-Meister

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    I don't believe you can run multiple outputs at the same time but I would defer to some of our more seasoned members on this one.
     
  11. D'tar

    D'tar Tele-Afflicted

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    Thats a great question! Im not an expert here so this is just a thought.

    Unless you had a transformer with multiple winds, one for each impedance, That would be a large hunk of iron. I think you would stress the tranny into failure rather quickly.
     
  12. Bendyha

    Bendyha Tele-Afflicted Silver Supporter

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    Yes, all that and more;
    upload_2019-3-17_0-43-27.png upload_2019-3-17_0-52-24.png

    It is quite well explained in this Radio Electronics artice from 1966.
     

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  13. D'tar

    D'tar Tele-Afflicted

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