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Old Ampeg SVT question (psycho?)

Discussion in 'Amps and Cabs [BG]' started by Rickenbackerman, Feb 5, 2002.


  1. Rickenbackerman

    Rickenbackerman

    Apr 17, 2001
    Laurel MD
    Ok, so I'm trying to learn about tube amps, how they work, how to work on them, all that jazz. I scored Gerald Weber's second book and was reading it last night.

    There's a paragraph in there about how the speaker outputs on old SVTs are deliberately wired backwards so that guys wouldn't blow speakers when using only one cabinet. He says when you plug in one cabinet, it's actually running off the 2-ohm tap, and making less power in the process. He says to get full power at 4 ohms, plug in a dummy jack into the external speaker output.

    This makes no sense to me. I can understand running a 4-ohm cab off the 2-ohm tap to make less power and save speakers that are under warranty. But if plugging in two cables uses the 4-ohm transformer tap, and you're using 2 4-ohm cabs, isn't that a recipe for destruction?
     
  2. Rickenbackerman

    Rickenbackerman

    Apr 17, 2001
    Laurel MD
    Thanks Psycho! I'm glad you're still around too!
    So, to put this in perspective...
    When you use one of the speaker outputs, the total speaker impedance should be 4 ohms. When you use both speaker outputs, the total speaker impedance should be 2 ohms. Correct?

    Assuming this is correct, Weber is just plain wrong?
     
  3. gmann

    gmann

    Mar 1, 2001
    Contact Dennis at Central Jersey Repair in Edison. He worked at the Ampeg factory in the 70's.