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Why amps sound good or bad

Discussion in 'Amps and Cabs [BG]' started by K Dubbs, Oct 21, 2004.


  1. K Dubbs

    K Dubbs Just graduated from OSU, Go Bucks!

    Mar 16, 2002
    Toledo, Ohio
    If a person were to round up all the solid state amps out there and eq adjust them for perfectly flat response, why would one amp sound "better" than another? What makes a Walter woods or an Iamp sound better than a behringer bx3000t? clearer? punchier? wamer?

    If it is higher quality components, what about the components makes them higher quality? Is it greater headroom? Some sort of greater analog/digital resolution (bitrate?) higher purity wiring? less resistive soldering on interconnects?
     
  2. brianrost

    brianrost Gold Supporting Member

    Apr 26, 2000
    Boston, Taxachusetts
    There's much more to an amp's sound than frequency response.

    1. How "fast" does it repsond to transients? How quickly does it damp the signal when a note stops? Is there any compression of your playing dynamics?

    2. How much detail can you detect in the sound? Are there certain aspects of the note that are revealed only with some amps but not others? Does switching amps make it seem like a blanket was tossed over the speaker?

    3. Is there noticeable harmonic or intermodulation distortion?

    Etc.
     
  3. K Dubbs

    K Dubbs Just graduated from OSU, Go Bucks!

    Mar 16, 2002
    Toledo, Ohio
    yeah, exactly. That's why I'm wondering what specifically, physically makes an amp sound better than another when both eq curves are identical. I want to know if wire/solder purity makes any real difference. I want to know what makes a cheap op-amp circuit in a preamp sound worse than a fully implemented high quality class A design. Pretty much, Brianrost, I'm wondering what physically makes the difference in your 1,2, and 3. What about an amp makes it respond quickly to transients? What components inadvertently compress dynamics? Is it just inadequate voltage range tolerances that create harmonic or modular distortion?
     
  4. IvanMike

    IvanMike Player Characters fear me... Staff Member Supporting Member

    Nov 10, 2002
    Middletown CT, USA
    i can only offer this. One thing about quality components is that they have very strict tolereances. The example i got form mica wickersham of alembic was that a cheaper amp might have a resistor in it that costs 1/10 of a cent that's supposed to be 1 kOhms. In reality that resistor might be anywhere from 750 - 1.25 K. Alembic uses resistors that cost 10 cents but are 1 K on the nose every time. The simple circuits seem to be the best approach as well. A lot of amps try to cram in too much "stuff" with the net result being a marginal tone. The more basic circuits seem to sound better, maybe partly due to a shorter signal path.
     
  5. Bob Lee (QSC)

    Bob Lee (QSC) In case you missed it, I work for QSC Audio! Gold Supporting Member Commercial User

    Jul 3, 2001
    Costa Mesa, Calif.
    Technical Communications Developer, QSC Audio
    As important but rarely mentioned is the actual design of the amp. A crappy, poorly thought out design with ultra high quality components is still going to be a lousy amp.

    IvanMike: I would guess that Alembic, like any smart manufacturer, uses higher and lower precision resistors where higher and lower precision are needed. Your example of resistors with 25% tolerance, though—I don't think they even exist.
     
  6. IvanMike

    IvanMike Player Characters fear me... Staff Member Supporting Member

    Nov 10, 2002
    Middletown CT, USA
    eh, i was just quoting someone else......... :confused:
     
  7. brianrost

    brianrost Gold Supporting Member

    Apr 26, 2000
    Boston, Taxachusetts
    K Dubbs,

    The full answer to your question would require a textbook about amp design!!!

    All amp designs have certain tradeoffs: price, ease of manufacture (or service) , size, weight, heat dissipation, etc.

    You can use op amps or other integrated circuits, discrete transistors or tubes. You can use diffferent circuit classes (class A, class AB, etc.) in each stage, you can choose different types of EQ circuits, etc. Each choice will have some impact in the final sonics.

    Wire and solder have almost no effect on an amp design. You don't want the wire to be oxidized or corroded and you don't want cold solder joints, that's about as far as it goes.
     
  8. ihixulu

    ihixulu Supporting Member

    Mar 31, 2000
    getting warmer
    You mean the Tara labs circuit board replacement wire I bought for $500 won't make me sound like John Entwistle?
     
  9. arizonabass

    arizonabass

    Feb 6, 2002
    Tucson, AZ
    Nope. You only get to sound like YOU! Be proud of that. (Yes, I know you're being silly.)

    :smug: