Tube amp question

Discussion in 'Amps and Cabs' started by mmp31, Feb 24, 2015.

  1. mmp31

    mmp31 Member

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    I've read that it's actually less harmful to a tube amp for the speaker load to be slightly less than nominal than slightly greater than nominal. For example, on a tube amp that calls for an 8 ohm load, it's better to have a 7.5 ohm load instead of an 8.5 ohm load. Is that accurate?
     
  2. bcmatt

    bcmatt Member

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    I don't think that is true. Neither of those should make much difference. Tube amps don't actually see an exact impedance that they need. Every design is different. Certain output tubes have an optimal range of impedances they like to see (typically in the thousands). The Output transformer will change the ratio to help match up certain speaker impedances to be in the right zone. But OTs also vary that ratio depending on the tonal effect they are going for within a somewhat safe range. All this is to say, it's not an exact science for tube amps, especially since there are so many variables to consider. It's not really something to worry about...
     
  3. swiveltung

    swiveltung Member

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  4. SteveO

    SteveO Member

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    Impedance varies with the frequency of the signal as well, so the ratings are all based on averages.
     

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