No! this isnt a joke Andrew.
http://stereophile.com/asweseeit/705awsi/
Theres some imformation there related to this.
http://stereophile.com/asweseeit/705awsi/
Theres some imformation there related to this.
I mean if we made an amp that had a frequency response of 5khz to 10khz and had 50% THD then I'm sure nobody could claim that it did not sound different to any hifi amp. But once you start producing amps with 20 to 20kz and 0.01% distortion figures its less clear especially given the vast differences in price some hifi amps cost.
But tube amps (and some transistor amps) routinely show large frequency response changes, too, especially from non-zero source impedance. Amps differ in recovery from overload- if something clips and is not perturbed, it will sound different than an amp that sticks, chokes, or blocks. Amps differ in dynamic stability. And so on and so on.
So it is (IMO) silly and (objectively) wrong to assert that because amp A and amp B could not be distinguished in a particular test, especially one that you can't even cite, that no differences between any amplifiers can be "proven." That's just simply not the case.
So it is (IMO) silly and (objectively) wrong to assert that because amp A and amp B could not be distinguished in a particular test, especially one that you can't even cite, that no differences between any amplifiers can be "proven." That's just simply not the case.
SY said:
If 0.5db frequency response is so significant, then how about the 10 or 20db deviation due to peoples hearing, rooms, speakers, and so on. All these factors vary so we cant possibly test an amp when all the other factors are varying can we?
But actually my point is not about frequency response because even the cheapest amps can easily achieve a flat response no?
Its not the frequency response that makes people choose a Krell over a Sony is it?
I just don't understand the whole premise of this thread. My initial response as you know was "really", as in "are we really going to have this conversation", when this subject has been mulled over about a billion times since transistors started being used for audio amplification. Build it, buy it, plug it in, listen, enjoy it or don't, and move on.
Professor smith said:
Nope, What you read in the Carver Challenge was that a very experienced EE/audio designer like Bob Carver, after 3 or 4 tries locked in a hotel room with all his best stuff(was that 12 boxes full?), at the peak of his game, with an amp he designed that had many little strategic adjustment pots, could almost equal a good tube amp. And he failed the first 2-3 times.
Little effort and little cost? Only if you are Bob Carver with his 12 boxes of test gear and "tweako out the wazoo" custom amp. And then it's 4 days and a case or 2 of red bull to get your wings. If you had to pay a guy to do this, it would be a fat check, better count on 5 zeros after the number.
And from your other article - the conclusion -
"The lesson was duly learned. Whether or not they can be told apart under blind conditions, amplifiers can have a major effect on a system's sound quality. And more important, normal listening had revealed what the blind test had missed."
Are you speed reading this articles and missing the real meaning?
Professor smith said:
Look at some measurements made by e.g. the "Stereophile" magazine. A good example may be from this years May issue, and i choose the test of the Pass Labs XA30.5 please see fig 1 under Atkinson's measurements. Into 2 ohms load there is drop from 10 kHz to 20 kHz of 0.25 dB.
In the April issue they measure the Vincent SV-236MK integrated. This seems to have 0.5 dB deviation.
Maybe the deviations from flat with more complex loads, e.g. electrostatics, is even greater. Maybe the deviations even show up in the midrange.
Well, it's 35-40 years since Otala (re)discovered TIM and all that, so surely it is not only a question of flat frequency response. However, it is safe to say that amplifiers' frequency response is modified by the load (including possibly speaker wire), and possibly in some cases, this is audible.
RK
My experience primarily as an audiophile, is that in large group listening sessions of comparing equipment, there is usually overwhelming agreement on the more obvious differences between amplifier sounds. Rarely do any two makes or for that matter models of amplifier sound exactly the same. Once again I need to reiterate and I do not mean to sound arrogant, ears trained over many years can become extremely sensitive to the slightest change in a set up. For the more sceptical,if you make a change to a system such as adding an ebony puck under a cd player, and then ask for the written comments from the audience without consultation, with similar experience, most often similar changes in sound will be described. In the case of the ebony puck the differences are often, to the well trained ear, quite dramatic in some set ups. The differences heard are also often similar for the ebony puck when added to different types of equipment as a support puck. That is, a more precise slightly more detailed and faster rhythmic sound.
So in my book if any one states that two types of amplifiers especially from different companies and different designs sound the same I would be extremely sceptical of that finding.
So in my book if any one states that two types of amplifiers especially from different companies and different designs sound the same I would be extremely sceptical of that finding.
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