"Official" All amps sound the same thread - Page 5

What always amazes me about threads like this is that they go on for pages with dozens of posts explaining what the so-called objectivist position is, and yet the so-called subjectivists never seem to comprehend it, let alone offer any meaningful counter-argument.

So, because I like banging my head against other people's brick skulls, let me try again to explain it in simple terms that even an audiophile should be able to understand, if he wants to.

If two amps sound different to you, there are three and only three possible explanations:

1) The amps are not playing at precisely the same volume.

2) You are imagining a difference (which may include misremembering what you heard earlier, even minutes earlier).

3) One or both amps is producing audible levels of distortion.

That's it. Unless you want to claim that you live in a universe where effects don't have causes, those are your only three options.

The most common logical error subjectivists make is to assume a priori that if they hear a difference, the cause is #3. But you can't just assume away the other possibilities. If you want to make the claim that there are audible levels of distortion, you have to conduct your comparison in a way that eliminates #1 and #2 as possibilities. (And we should all know by this time what that way is.)

The other key point is that instances of #3 are rare, especially if you are using modern equipment. The two most common causes of amplifier distortion are:

(a) Impedance mismatches with speakers, causing frequency response errors.

(b) Distortion caused by pushing an amp beyond its capabilities.

Possibility (a) is nearly unheard of among modern solid-state amps. And (b) turns out to be a lot less common than you might think, because when you're listening to music it takes a substantial amount of clipping before it becomes audible.

So going back to the three possibilities above, not only is it the case that you can't eliminate #1 and #2 without doing a blind, level-matched comparison, but they are also far more likely explanations than #3.

Now your starting to make it argumentative as usual, I already read that paper before thanks but my point is you in this thread said I am just spinning out even more.
Either I am talking rubbish on a subject you personally admit not even trying yourself, or I am talking common sense.
And BTW I notice your twisting the argument once again to come back to distortion.
Where the hell did I mention distortion?
This goes beyond that simple thought.

Taking this another step, you also like to say how people like to choose amps or CD players/etc if they have higher gain or voltage because they cannot perceive the difference as pure loudness and bias.
Well sorry but this another thing that does not necessarily stand up to the real world.
On Saturday after listening to some speakers, the salesman connected a DAC into the system as it was going cheap and I had 1st refusal.
1st thing both myself and a friend noticed was the loudness that was not a little but actually loud.
We had to turn the preamp down by a 3rd (equal on this system going from their large room to their medium room).
Now my friend is not aware about voltage outputs so I asked him did he notice anything, he said it was loud.

For 3 tracks I tried to convince him that the bass/treble/airy fairyness was oh so much better (when in fact it did not sound any difference apart from loudness to me)
Well he kept saying err nope sounds the same to me.
So one urban myth that you can always convince someone they hear something they do not.
After the 3rd track I decided to check how it was setup just to see if there was a reason why it sounded so identical, and it was then that we could see that the salesman had only connected the digital cable between CD Player and the DAC, while the RCA was not changed and was between the CD player and the preamp.
So this explains why there was no sound difference, although this setup did cause a higher voltage output from the CD player to the preamp.

Having the DAC connected correctly again it required the volume to be turned down again by some more (due to the higher voltage from the DAC).
This time differences could be noticed in bass and also treble.

However going by what you say we should had been biased that we liked the DAC64 1st time because to us the DAC must be better due to its looks or that it was connected to improve the sound, and also because of the volume increase caused by the incorrect setup.

The point of the story, try for yourself real world experiences where you look to investigate and engineer differences for the various factors.

Sorry but I am bailing from this thread now as I really cannot be arsed to deal again with the repeats of the CD thread, you guys say whatever you want.
Peace all
DT

I love the boobs who sit there twiddling the volume control around and actually making things sound different, and then they puff out their chests and brag that their ears are so sensitive and their gear is so resolving because they think they heard a difference that no one else could hear.

Your answer implies that you think there's something wrong with the amp.
I don't believe that is that case... I have five of these amps and I don't think they're all broken in exactly the same way.

I'm no amp snob, but there are differences in how amps sound. I couldn't tell any significant differences between my Bryston 7B ST mono blocks on my B&W 801sII speakers, so I sold the Brystons.

Conversely my little Trends Audio TA-10 tripath amp sound better than the crown driving my mid/hi Altec 288 compression drivers (115db/w/m sensitive).

None of these differences were huge, so never again will I sink big $ into an amp.

Do you have any examples of people actually doing this, or do you just assume they must because there is no way for an amp to sound different?

Since all amps have varying degrees of measurable distortion is it possible that a particular amp may add something that could technically be called distortion but does in fact add a pleasant character to the music?

Remember a guy named Bob Carver? He had a whole line of amps that were designated the TFM series. That stood for Transfer Function Modified I believe. He was supposedly trying to emulate the sound of a tube amp. Some may say he added distortion of some sort, others will say that his amps sounded warm, dark, musical or what have you. I will say that they do definitely have their own character. IMHO of course.

IME, most people--including most audio enthusiasts--do not know what a power amp actually does, let alone how to tell whether they actually perform differently.

Since you can write, I have to assume you can read. So read post #122.


Yes, but so what? If you're twiddling with the volume knob, you're never gonna know. See, again, post #122.


The people who say he added distortion of some sort are the people who know what they're talking about. That is the only way it would be possible. See, yet again, post #122.

DT, I've got another point to the story. Find a store where the guy knows how to hook up equipment or do it yourself. I doubt that salesman is capable of putting anything into the right hole. Second, just bring a burned test tone and portable multimeter and set your levels the right way.

No. My answer implies that it makes more sense to bounce this off the people who make and sell your amp.

With speakers that sensitive, you need an amp that performs well at fractional watts. Noise and all that.

He stuck a resistor in the output path.

No need to bounce anything. The question was *IF* all amps sound the same then how come my crown sounds worse bridged. To spell it out I'm just giving an example of how amps don't all sound alike... even the same amp in a different configuration.


Yep they need to be driven with something that sounds good in the first few watts (at least for home use). Once again another example of how not all amps are created equal - but it takes a certain speaker to bring out the differences. The trends audio amp would have been useless on the B&W's for spirited listening levels - horses for courses as they say.

I have no idea what worse means nor what the sub is, how connections were made. But to not avail yourself of a toll free call to Crown...

Sigh. Said to myself, again .... don't gets involve. I'll let you all gets on the debate in peace.

The definition of worse and/or the sub (other than impedance) in this case is irrelevant since the argument is all amps sound the same.

In other words since the sub sounds fine running off a single channel, then (since all amps sound the same), the crown should sound identical in bridged mode right?

As for the connection... a monkey could switch an amp from bridged to stereo mode in less time than it took me to type this sentence. It's either connected correctly and you get sound, or you've created a short, or you've connected it out of phase (which is not the case).

No one's made that argument. Try reading for a change.


Not necessarily. See post #122.

You made that argument in post #122. BTW the amps output levels were match before and after the bridging. The amp wasn't being pushed in either configuration (my sub is an estimated 100db/w/m in room).

I'm also curious as to your qualifications to make such sweeping statements. Do you have a Bachelors Degree in Electronics or are you just giving your opinion?

I asked this very question to our friend Kurt from Blue Jeans Cable. Here is his very detailed and informative reply:

"Yes, absolutely, it's possible for similarly-spec'd amplifiers to sound
different from one another. This is very different from, say, expecting
cables to sound particularly different from one another; amplifiers are
active circuits; they have circuit impedances that vary with frequency,
filtering circuits which modify signals incoming, outgoing, and in process,
and semiconductors (or tubes) that have different noise floors, gain
characteristics, et cetera. This is a bit like designing a camera lens:
there's no simple, straightforward design that combines the best of all
possible outcomes, and so every design is something of a compromise between
competing objectives. The ideal amplifier is perfectly linear within its
operating frequency range, causes no distortion, cuts off sharply outside
its intended frequency band, and presents all of these characteristics
regardless of the type or level of input signal and the amount of gain
required--but this ideal amplifier is an idea, not a reality, and real-world
devices can and do differ in meaningful, audible ways, even as they attempt
to realize that ideal.

Now, it's also probably fair to say that there is a lot of overstatement,
and some misconceptions, that people engage in when DESCRIBING the
differences between amps. Two good amps, both fed the same material and
driving the same speakers, ought to both sound good; but they may sound
different from one another, within a limited range. Obviously, if they
really sound profoundly different from one another, something is probably
the matter with one or both of them. We run into this in audiophile stuff
from time to time; for example, tube amps will often be said to be "warmer"
than transistor amps. That's true if one takes a certain view of what
"warmer" means; tube amps typically soften the highs a bit and that causes a
presentation which people often describe as warm. But that "warmth" comes,
of course, at the price of accuracy of reproduction of the input signal.
Whether one likes it or not is, of course, another matter.

Thanks,

Kurt
BJC"

I agree with Kurt as his explanation is the most consistent with my own listening experiences.

Sounds very reasonable to me. Sort of position 2 with a little more wiggle room for potential audible differences. Let's call it "position 2.2".

I'd say it's closer to 2.5

Then read it again, because you didn't understand it the first time. In particular, you may want to think about how it would be possible for a post that starts off with, "If two amps sound different to you..." could possibly be arguing that two amps can't sound different to you.


Howby ear, SPL meter, or voltmeter?

And even if you did level-match properly, you still didn't deal with cause #2. So we can't really say yet that the amp sounds different bridged and unbridged.

If, OTOH, you were to do a truly blind and properly level-matched comparison and could tell the difference, then I'd want to see some measurements to find out what's going on. Because something must be going on. And it isn't good.

I'll betcha it's one of them home made subs made & modelled on a software program without any subsequent measurements.

Mcnarus, you're stating your opinion as fact. We're just going to have to agree to disagree unless you can show some qualifications or back up your three part theory.

BTW the signal was level matched with a 60hz sine wave at approx 3 volts across the amp terminals under load. There is no need to DBT when something is as plain as the nose on your face. Why would anyone wish their amp to sound worse bridged?

What would my qualifications have to do with anything? And especially, what would my engineering qualifications have to do with my statements about audiblity?

As for my "three part theory," I invite you or anyone else to offer any other possible explanation for a perceived difference between amplifiers. This isn't some deep scientific theory. It's based on a few simple psychoacoustic concepts and definitions.


You wish. I can't tell you how many times I've heard somebody claim an "obvious" difference that, once you did the real work, turned out to be not-so-obvious after all.

But if you really did hear a difference, then in either one state or the other your amp is audibly distorting. I really think you ought to look into that.

You say that like it's a bad thing (well the first bit anyway)

The fact is

1) the sub is irrelevant as previously stated.
2) I've used two 402D amps on two VMPS Larger subwoofers and they both suffered similar sound issues as per my currect sub
3) My current sub is a tapped horn which I designed with Hornsresponse. I have measured the FR and use a Behringer Ultra Curve Pro to get a relativity flat FR at the listening position (room nulls not withstanding).

It's my opinion however, that FR is one one of many many measurements that need to be taken and FR alone tells you very little about how it sounds with real program material. If you want to come and help me lug all 300lb of sub and amp down stairs so I can do some real outdoor measurements I'd be much obliged. Personally I think I'll wait until summer when have to bring it outside to paint it.

FWIW Danley Sound Labs sells a tapped horn with DSP and amp that uses pretty much the same driver I have in mine. It retails for $4K. His will have a smoother FR out of the bandpass due to his use of resonators. I had to use DSP in my design.

If you had a B. Engineering degree in electronics and designed amps then I believe you'd have some credibility on the subject.

As for perceived differences see what was written above about high sensitivity speakers and signal to noise ratio. Not to mention power supply hum etc.

If you're ever in Denver PM me and you can come and listen to the differences for yourself.

I simply can't resist to suggest position 5: Amps simply are different in design, built, looks, and but of course the way they sound. To briefly support the statement, over the years, I had at least 2 tons of amplifiers (by weight) in my systems for longer period of time, which probably means at least additional 2 tons on trial. My back remembers most of them, my ears some of them. They all are different, not just by weight, but in the way they sound.

The situation gets a bit complicated with specs and pricing. For the most part, specs are not that important, and price can also be deceiving. Not to say that poor spec'd cheap amps are good, but how they sound in a particular system is what counts. Also not to say that you have to mortgage your house to get a high-end amp. I always subscribe to sanity, and the only real difference is whether you like the sound (and the looks), or not.

Saying that all amps sound the same is almost close to saying that all the girls are the same (not sure if this is appropriate, apologies to any ladies around, it is not quite a comparable situation, but emphasizes the point), all the vine tastes the same, food is nothing but a fuel, and that life in general sucks. I am sorry, but I don't subscribe to that point of view.

I don't intend to argue on the point, simply a contribution to the thread

And just what did I say that you think I'd need a BSEE to know???

We're talking about audibliity, not engineering. You seem not to be aware of that.


Yes, well, noise would be a form of distortion, no? Can't quite understand why you're arguing with me.


I don't care whether you hear a difference. What I care about is why you hear a difference. What shocks me is that it's your gear, and you don't seem to care why there's a difference.

But of course. It's inconceivable that two things could be designed differently but sound the same.


And have you ever once done a blind, level-matched comparison of any of them? Do you even know why you should?


You also don't seem to subscribe to empiricism.

[And have you ever once done a blind, level-matched comparison of any of them? Do you even know why you should?
[quote]

I have done many blind tests in my life. Level matching gets a bit tricky, but we tried our best. I guess I did it for fun? Any other reason why I should have done it?

The "original" all amps sound the same thread. Thousands of posts that are EXACTLY the same as everything already posted and then some. This current one is nothing more than a recycle, at best.

http://www.avsforum.com/avs-vb/showt...ght=amps+sound