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Watts is Watts, right?

Discussion in 'Amps and Cabs [BG]' started by Stinsok, Aug 2, 2004.


  1. Stinsok

    Stinsok Supporting Member

    Dec 16, 2002
    Central Alabama
    I read two different opinions on the subject. Some people say that tube watts are louder than solid state. Some say a watt is a watt. Is there any evidence to support either? Keep it friendly!
     
  2. Stinsok

    Stinsok Supporting Member

    Dec 16, 2002
    Central Alabama
    I take that back. Come out swinging!
     
  3. Trevorus

    Trevorus

    Oct 18, 2002
    Urbana, IL
    Tube amps amplify a bit differently. When you crank a tube amp, it amplifies a lot of even order harmonics. Which we percieve as louder. Solid state amps don't do that.
     
  4. 1W = 1W.

    on the other hand, a tube amp can be pushed harder before it starts to sound dirty. that allows it to create much more average power compared to peak power. solid state amps will sound dirty much quicker, so they can create much less average power compared to peak power.

    tube amps also have a transformer on their output, which lowers damping factor quite a bit. while this doesn't make any more power, the speaker is a little more out of control, which can often sound louder, even if it isn't any louder.

    what that translates to is that a tube amp will sound louder for the same power rating. however, a watt is still a watt, and both of them driven at the same level with the same low distortion will be the same loudness, more or less.

    robb.
     
  5. jive1

    jive1 Moderator Staff Member Supporting Member Commercial User

    Jan 16, 2003
    Alexandria,VA
    Owner/Retailer: Jive Sound
    Watts are a measure of electrical power, not of audible volume. Decibels measure loudness.

    Microwave ovens, lamps, hair dryers, etc. are also measured in watts. Watts of power can be transformed into things such as heat (therms), light (lumens), motion (RPMs) and sound (decibels).

    So a watt is a watt. But how those watts are turned in to decibels differ from amp to amp.
     
  6. xyllion

    xyllion Commercial User

    Jan 14, 2003
    San Jose, CA, USA
    Owner, Looperlative Audio Products
    Watts are watts, but amp ratings are not. There is no single standard that all amp manufacturers use to determine the ratings of their gear. Amps don't just stop putting out more power when they hit their rated value. As you turn up the output, the amp begins to distort. The severity of the distortion is dependent on the design of the amp and how accurate the original rating was.
     
  7. notanaggie

    notanaggie Guest

    Sep 30, 2003
    It's even better than that...............but that is true. Trumpets produce evens, and they are loud, particularly considering the somewhat low power input (the breath). They seem jumpy and "forward".

    Now, a MUTED trumpet produces largely odd harmonics, the mute is made to absorb the evens. It seems softer than it is, and "behind" itself..

    So a predominately odd harmonic structure is actually muted, while evens are louder as far as our perception.

    A tube amp, typically produces plenty of evens due to the random biasing of the distortion stages, and the possible mismatches in output tubes, clipping of drivers etc. Asymmetrical clipping, resulting from the above, is even harmonics.

    Most opamp-based solid state amps tend to produce very clean and symmetrical clipping. That however is largely odd harmonics, so they seem muted.

    Not only that, but the low feedback in most tube amplifiers means clipping is not "clean", the resulting wave is not very square. They tend to have a structure of low-order harmonics, mostly or completely "musically related".

    High feedback in opamp-based solid state amplifiers produces very square waves, with very high order harmonics. The 15th or 25th harmonic is no longer musical, it is just noise, even or odd.

    So tube amplifiers tend to have the loudness-enhancing even harmonics, and low order musically useful ones at that.

    Solid state amplifiers tend to have odd harmonics, giving a muting effect, and they tend to extend up into the range which is just noise as well.


    This isn't a law. There are rotten-sounding tube amps. There are decent-playing solid state amps.

    The older Crate amps with the patented tube simulation seem to play pretty nicely. The newer ones seem to have lost some of the recipe.

    Other simulation-type (not the DSP ones) seem to be OK too. Several companies have them.

    Some of the DSP amps are OK too, but they are usually different, and seem much more "simulated" to me. Kinda like seeing a picture of a good beer, instead of taking a drink.