Can I please mention that #1 the first link you posted was a speaker test, not an amp test so it's pointless, and #2 the second test was with home audio power amplifiers (as opposed to A/V amplifiers) that have no on board processing what-so-ever, so yes, they would sound identical, as they are only amplifying the signal recieved, not processing it at all. Also, it would be receiving either a low level or a high level analog signal, completely eliminating even the possibility of a digital-to-analog converter colouring the sound. While I do agree with you that there is alot of hogwash in amplifier "features" and sound, it may help your case if you post tests that are truely relevant to the arguement at hand

 

...So my link was on BIAS. Fozz was saying he was immune to it.

I was identifing the importance in making sure bias was removed from any test because to be human is to be biased. Therefore hilighting the importance of blind ABX tests to determine amplifier differences.

Simply taking someones word for it
-are you biased?
-Naw man no way not me!
Simply won't cut it.

So I am sure if we prove bias affects speaker choice, then you can make the next logical leap and understand it will also affect amplifier choice. no? And any other choice indeed.

 

Of course it would be easy to design an amplifier that can't amplify 20hz to 20khz flatly. Simply look at most class D mono blocks... they usually only go up to 300hz or so. But it's not a bad design. And someone could implement a really bad design but most amps are a rehash of designs that have been around for ever. So why would they want to, it is easier to just go with an easy and proven design. Bad designs are usually limited to things like noise floor and prone to induced noise (which is usually people taking these old designs and not implementing the new "best practices".)

If staging was such an obvious thing to detect then people would be able to differentiate one amp from the other in the tests that have been conducted. It is possible that one will stage different then the next, it is very likely that most amps right and left won't be perfectly matched so in a case where the difference are audible that would play a role on staging. So the difference one could hear would once again come down to volume.

 

I can simply rebutle to this:
No they dont.

And thus my subjective statement effectivly cancels out yours.

this is why we need the scientific method.--click me

Without it we are doomed.

Let me point out this discussion is very similar as a religion topic. Notice that one can't apply the scientific method to religion but one can to amplifiers and humans so the question is why have faith in amps when SM can be used? I don't get it.

 

Iit's not clear from what you wrote but when I say blind AB testing I simply mean one isn't aware of which amplifier one is listening to.

 

so far here are the facts:

1. amplifier challenge has had no winners take home the 10 Gs, additionally no other amp challenge has resulted in anyone being able to hear a difference in a scientific test (not saying nobody can..it just has not happened yet).

2. the amp test allowed any amplifier against any amplifier...that means you can bring a $100,000.00 amp and put it against a Crutchfield $60.00 Profile amp and still won't be able to tell the difference under the test conditions (read them before commenting).

3. amps are certainly different from each other in many other ways and those are the reasons to buy them..sonically though, there is no evidence that humans can hear the differences. As with everything else in this world, scientific evidence is the only acceptable form ofevidence as all others are suject to interpretaion, emotions, hearsay, bias, etc...

conclusion:

Obviously the sonic differences are so minute that any noob thinking about purchasing an amplifier (probably holds true for processors and many other electronics as well, but since we're talking about amps, i'll stick to that) should really concentrate their funds on more important factors like application, dimensions, reliability, etc...For those who have been around the block so to speak, enjoy what you enjoy.

 

Already knew that (just to keep us on the same page)

But again, we already knew humans are biased, and we definetely know there are differences in speakers. Did you actually read your own post? The graphs clearly show that people were picking differences in the quality of sound, the test was exploring visual bias, man. We're talking about a difference in sound between amplifier designs, not whether the visual representation/reputation creates bias. I'm sure Fozz is well aware that humans have bias, but that's not the question... So the first one shows bias is present, sure, but if you read the graphs, it is null and void. People only preferred certain speakers because of the way they looked, how much they cost, and/or who made them. The second one is still just as pointless because they are strictly power amps, no processing. I think you are on the right track though for sure, because the fact that these tests also don't apply just strengthens the fact that no one has actually properly tested what we are talking about

Nooooooooooo. We already know speakers have different tones and response curves. Speakers do sound different, and if you wanna be picky, no two drivers sound the same, even if they are the same model build by the same person on the same day. Most variations we can't hear, but without a doubt, speakers sound different, driver-to-driver. Bias will affect it much in the same way the first test describes it, but up until now all you have proven is that bias will affect choice and percieved quality... aka psycho-acoustics. What has not been determined is if amps actually do sound different

 

I agree with this. Most people focus on the sound of the amps in question but I believe that you have more chance of staging and imaging being different from one amp to the other. How much crosstalk is there, or feedback? What's the slew rate, or how much current is available for high phase angles, wild reactive loads, low impedances and whatnot. Most of this doesn't show up at moderate listening levels on light jazz. Start running the amp hard though and how does it stack up then? Just like any car engine can pull a car down the road at 80km/hr but what about when you have to pass that B-train and you didn't leave enough room.... That's when the differences show themselves - when the big guitar riff at the beginning of Money For Nothing hits the drums, what happens then? Does your amp suck it up or does the guitar crunch because the midbass just stole all your current?

Once you are doing 120 down the freeway though, most of this discussion is pointless..

 

Agreed. More or less what I have been eluding to, and another member actually posted it straight up. It comes down to the processing and the components and design behind it. Things like crosstalk are a great example. AAAAAAA is right that it comes down to

But the key is that is what makes amplifiers sound different, given all controllable parameters are set equally. If an amp is strictly a power amp with no processing, it will NOT sound any different. If there are circuits within the amplifier that are designed to shape the waveform in any way, there is obvious colouration of the tone. More times than not, quality components are used and this colouration can be tuned out to equalize the tone with the very components within the unit that are suspect to begin with lol The imaging, staging, loudness, and distortion are all going to be affected by the components and topology used, hence where differences can occur (I know that how the material was recorded will also play a factor, but let's focus on the amp side of things lol). NOT all amps sound the same out of the box, we've already determined that some (not all) mfg's will shape the overall tone for that "signature sound". At the same time however (and without statistical data to back me, sadly), I am almost willing to bet that 95% or greater amps can be adjusted to neutralize these effects, essentially rendering all amps equal in sound. Some things can be massaged without touching the amp at all (imaging and staging come to mind....) but I would also say that 98% of the issues we face in the reproduction of sound is not the gear, it's the environment you're working with.

 

[QUOTE=AAAAAAA;613992]...So my link was on BIAS. Fozz was saying he was immune to it.

I'm not immune to bias, I just dont think I'm effected by it in audio. At least not to any serious degree. I do have any brand prefferances, nor will I. I've heard every budget level of audio system and more speakers than I would like to admit. But that is another topic.

I mentioned already that a watt is a watt. Which means I agree with AAAAAA and Veeman. But I still say not all amps sound the same. Here is an example of what I mean.

I had a set of custom made mono block tube amps. They were a solid 15 watts at 4 ohms. I have no other specs on them, but I can tell you, they were not a very accurate amplifier. The level of distortion was probably way beyond what most would consider normal. But they were also my favorite "sounding" amplifier. There was no questions that these mono blocks added a large degree of their own charecter to the sound. But they also made the music more fun for me to listen to.

This may not be a fair comparison, but its exactly what I'm trying to say. Some amplifier add their own charecter.

We are a little off topic here, but I hope you get the idea.

And for the record, RC was challenged, but to my knowledge, he refused to allow the challenger to take part in the test. I don't know of anyone who actually did take the challenge.

For those that are interested, I'm willing to provide my listening room to give our own CCA version of this test. I would provide the listening area, and some good quality speakers. Might be a fun trial. Nothing would really be accomplished, but if would still be a fun day.