All amps sound the same.

ab0tj
ab0tj Posts: 40
Ok, sorry for the clickbait title. I just wanted to get a discussion started on the science behind why this is not true. So, here's what I've learned/realized recently...

Many that make the claim that all amplifiers sound the same like to cite Ohm's law as an example. The claim is that for a given load (an 8 ohm speaker for example), watts equals volts times amps so there is no possible way a large amplifier can deliver more current at a given power level than a small amplifier. Sure, this part is true. But there is more to the picture. For the sake of discussion, we'll ignore the fact that the math is more complicated for a speaker due to the fact that this is an *impedance* we're talking about, not a resistance.

So, given all this, the math says an amplifier will put twice the power into a 4 ohm load versus an 8 ohm load. Yet if you look at the specifications of many well respected amplifiers, this is usually not the case. Why? Because an amplifier isn't a perfect constant voltage source. As the current drawn from the amplifier goes up, the voltage drops a bit. How much it drops depends on the amplifier design.

Most users of this forum will already know that the resistance (impedance really) of a speaker varies with the input frequency. This interacts with the amplifier by dropping the voltage, and thus the wattage, more for certain frequencies rather than others. Some amplifiers will be better at "holding up" the voltage at the lower points in the speaker's impedance curve than others. How this affects the sound will depend on the design of the speaker itself. This is exactly why it is important to match the amplifier to the speaker. The complex nature of all these interactions is also why it is best to use your ears to choose an amplifier instead of just looking at specs... If you can't audition the amplifier with your speakers, at least ask someone who has used the combination.

This is only one of many things that can "color" the sound, but my point is that this is not magic. The math backs up the claim that not all amplifiers sound the same.
Marantz SR6012, Parasound HCA-2200II, LSiM705 L/R, S35 center (yeah, I know...), 2x PSW505

Comments

  • tonyb
    tonyb Posts: 32,902
    No offense, but most here already know amps don't sound the same. It's a topic beaten to death over 20 years. Wish I could say the same for other forums who proclaim this, along with all dacs sound the same, cables don't matter, and a host of other kooky conclusions.

    If you recently learned this, good for you on moving forward. Keep an open mind and let your ears judge.
    HT SYSTEM-
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    Cables-
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  • motorhead43026
    motorhead43026 Posts: 3,892
    Dude, buy that Parasound and call it a day.
    2 channel: Anthem 225 Integrated amp; Parasound Ztuner; TechnicsTT SL1350; Vincent PHO-8 phono pre; Marantz CD6005 spinner; Polk SDA2BTL's; LAT International speaker cables, ZU Mission IC's and power cables all into a PS Audio Dectet Power center.

    Other; M10 series II, M7C's, Hafler XL600 amp, RB-980BX, Parasound HCA-1500 amp , P5 preamp, all in storage. All vintage Polk have had crossover rebuilds and tweeter upgrades.

    The best way to predict the future is to invent it.

    It is imperative that we recognize that an opinion is not a fact.

    Imagine making politics your entire personality.
  • ab0tj
    ab0tj Posts: 40
    tonyb wrote: »
    No offense, but most here already know amps don't sound the same. It's a topic beaten to death over 20 years.
    Sorry if I missed it, but every topic I have seen here where it has been debated, people just say "no that's not true", and never really get into *why*. I just thought it would be interesting to get some of those reasons put out there. I'll drop it then :D
    Marantz SR6012, Parasound HCA-2200II, LSiM705 L/R, S35 center (yeah, I know...), 2x PSW505
  • ab0tj
    ab0tj Posts: 40
    Dude, buy that Parasound and call it a day.
    I will be doing just that... I asked about the comparison between those amps on here because I live in a podunk town where it would be difficult for me to audition before I buy, and there's a high likelihood that people here have used both
    Marantz SR6012, Parasound HCA-2200II, LSiM705 L/R, S35 center (yeah, I know...), 2x PSW505
  • motorhead43026
    motorhead43026 Posts: 3,892
    edited July 2018
    I was referring to the ancient question you put forth about "do all amps sound the same" No they don't, is why you were advised to buy the Parasound.
    2 channel: Anthem 225 Integrated amp; Parasound Ztuner; TechnicsTT SL1350; Vincent PHO-8 phono pre; Marantz CD6005 spinner; Polk SDA2BTL's; LAT International speaker cables, ZU Mission IC's and power cables all into a PS Audio Dectet Power center.

    Other; M10 series II, M7C's, Hafler XL600 amp, RB-980BX, Parasound HCA-1500 amp , P5 preamp, all in storage. All vintage Polk have had crossover rebuilds and tweeter upgrades.

    The best way to predict the future is to invent it.

    It is imperative that we recognize that an opinion is not a fact.

    Imagine making politics your entire personality.
  • tonyb
    tonyb Posts: 32,902
    ab0tj wrote: »
    tonyb wrote: »
    No offense, but most here already know amps don't sound the same. It's a topic beaten to death over 20 years.
    Sorry if I missed it, but every topic I have seen here where it has been debated, people just say "no that's not true", and never really get into *why*. I just thought it would be interesting to get some of those reasons put out there. I'll drop it then :D

    If you go back far enough in the archives, you'll find many reasons. Gets old rehashing the same stuff from the naysayers who read an article on the web proclaiming the opposite. Many of us avoid these topics.

    In todays day, the internet is a great tool, but it can also be confusing to some with limited experiences. Audio is the type of thing where ya have to get into the weeds, you just can't sit on the sidelines and read internet articles and make judgement calls based on that.

    Most members who participate here, are well into the weeds of audio. Hang around, ask questions, join the fray and have some fun along the way. Welcome to the forum.
    HT SYSTEM-
    Sony 850c 4k
    Pioneer elite vhx 21
    Sony 4k BRP
    SVS SB-2000
    Polk Sig. 20's
    Polk FX500 surrounds

    Cables-
    Acoustic zen Satori speaker cables
    Acoustic zen Matrix 2 IC's
    Wireworld eclipse 7 ic's
    Audio metallurgy ga-o digital cable

    Kitchen

    Sonos zp90
    Grant Fidelity tube dac
    B&k 1420
    lsi 9's
  • ab0tj
    ab0tj Posts: 40
    tonyb wrote: »
    If you go back far enough in the archives, you'll find many reasons. Gets old rehashing the same stuff from the naysayers who read an article on the web proclaiming the opposite. Many of us avoid these topics.
    Fair enough. B)
    Marantz SR6012, Parasound HCA-2200II, LSiM705 L/R, S35 center (yeah, I know...), 2x PSW505