Amp question.

[amey01]

This is all measurable. If one wanted too they could take a number of measurements, of signals that they enjoy the sound of, analyze them, and then they'd know what distortions they enjoy. Not unlike what Bob Carver did years ago.

Sure - name one amp that comes with these specs.

 

[MPS]

Keep in mind that when speaking of clipping this is not something that can always be reliably heard. In order to find out for sure if an amp clips or not you need to take a measurement, via an instrument (an oscilloscope is ideal) and look to see if any clipping (brick wall distortions) shows up on the trace.

For anyone running challenging speakers this really is a must component to add to ones arsenal.

Be aware that many source material has already serious clipping included. Samples can be found in various internet sites, look for loudness war etc..

 

[snyderkv]

Be aware that many source material has already serious clipping included. Samples can be found in various internet sites, look for loudness war etc..

Interesting read. No mention of movies. I guess it just effects certain CDs plus I would suspect most people on this forum listen to genres that generally don't suffer from hyper compression

 

[Bevensee]

Distortion in amps is a far more complex thing that merely clipping. All sorts of intermodulation products start to appear way before clipping. And this can be vastly different from amp to amp. Another thing is crossover. When listening at low level, I find powerful Class B amplifiers very often sounding horrific. A much prefer amplifiers that are biased high into class A, so that they don't suffer from crossover distortion at low power levels. I know that the price to pay (for the same power supply and cooling) is reduced output power. I also believe this in one of the reasons many people like tubes with ESLs.

So in relevance to the original topic of the thread: I second Roberto's initial answer: Compare different amps not only at high level, but also at low level. This requires time and a quiet room, but is well worth the effort. Trust your ears, not the price tag.And remember that even the most elaborately CNC machined front panel does nothing to improve the sound.

 

[Pneumonic]

Sure - name one amp that comes with these specs.

The point wasn't to suggest that an amp with your specific specs is readily available but, rather, if it were then it could be objectively measured, and you'd know why it sounded the way it did to you.

 

[Pneumonic]

Be aware that many source material has already serious clipping included. Samples can be found in various internet sites, look for loudness war etc..

Of course this is so.

 

[Pneumonic]

Distortion in amps is a far more complex thing that merely clipping. All sorts of intermodulation products start to appear way before clipping. And this can be vastly different from amp to amp. Another thing is crossover. When listening at low level, I find powerful Class B amplifiers very often sounding horrific. A much prefer amplifiers that are biased high into class A, so that they don't suffer from crossover distortion at low power levels. I know that the price to pay (for the same power supply and cooling) is reduced output power. I also believe this in one of the reasons many people like tubes with ESLs.

So in relevance to the original topic of the thread: I second Roberto's initial answer: Compare different amps not only at high level, but also at low level. This requires time and a quiet room, but is well worth the effort. Trust your ears, not the price tag.And remember that even the most elaborately CNC machined front panel does nothing to improve the sound.

Any distortion (ie IM) happening before clipping would be indicated in the amps distortion specs however.

Really, the issue at hand is that no amp (that I am aware of) is spec'd when being clipped but only in linear, non clip mode. However, many users operate an amp in clipping mode. The problem is too few realize they are doing so. If they did, they'd understand why the amps they use sound so different from each other.

 

[roberto]

SET amps have measured distortion well above 1% but are considered by some to be the most musical amplifiers made today.

Manufacturers of this type amp include Cary Audio and Lamm.

GG

Yes, I think that too Gordon, but only for even distortion. Only tube gear. Happy listening!

 

[Bernard]

We don’t listen to and enjoy music on our systems through objective instruments, so why use those instruments as the final arbiter of sound quality? Certainly objective measures can play an important role in the selection and improvement of audio and setup, but listening and hearing are very complex. The notion of objectivity is misused in audio, and this is mostly due to faulty double-blind experimental designs to test whether audiophiles can hear the difference between equipment/cable changes.

Great post Mark (all of it, but I didn't want to quote it all).

It's also those extended sessions that enable us to determine if equipment that is impressive to start with is tiring in the long run.

 

[amey01]

The point wasn't to suggest that an amp with your specific specs is readily available but, rather, if it were then it could be objectively measured, and you'd know why it sounded the way it did to you.

And by the same token - my point wasn't that you can't measure certain things - just that in order to measure with any meaning then it is so complex, and more importantly, the inter-relationships are even more complex, it is nigh on impossible to put on paper - you just have to listen.

I'd actually go as far to say as we don't even know what to measure in a lot of circumstances.

 

[Gordon Gray]

True indeed. However, staying on theme of the OP thread, he would hear said distortion levels and could therefore (very likely) tell the difference between this high distortion amp and, say, a low measuring one.

Perhaps. But as we all know, or should know, measurements are one indicator in determining subjective amplifier performance.

Many other "non measurable" factors influence final sound quality and musicality.

 

[timm]

Some great posts. Why is it so difficult to understand that the analog instruments we listen with called ears come in all different shapes and sizes? They hear different frequencies and are more sensitive to others. A measurement is simply a basis or the starting point. To say it all sounds the same because of a measurement is not accurate. Before the sound hits your ear it obviously has to go thru the speaker which exudes some type of load on the amp. Some amps react well with the load while others get squirrely which impacts the final sound. So it isnt just the measurement , it is also the interaction of the speaker with the amp and each individuals ears and personal tastes. Hence the need for auditions. Relying on specs only does you a great dis-service. i think ameys question on what we are measuring is a great point

 

[Gordon Gray]

Beats me timm.

Seems some people need to quantify the quality of a subjective / personal listening experience, with the associated myriad of of variables, into some sort of number analysis.

How dare you mention "ears" as a factor.

GG

 

[twich54]

Beats me timm.

How dare you mention "ears" as a factor.

GG

Gordon, it's not the 'ears' that's the problem.....rather the 'brain' that they are connected to !!

 

[Pneumonic]

I guess for me it boils down to this:

Since not one of us has identical systems, setup in the same room, with the same music being played, any comparison on what any us can or can't hear lacks a true reference and is nothing more than an exercise in futility since it's simply a battle of subjective, I hear this, you hear that, opinion.

In the absence of such reference many people use science, or maths, or measurements as a reference point since it's the only way to bring into the fold some element of objectivity which can be referenced by everyone.

For me:

If I can hear it, and measurements suggest I shouldn’t be able to hear it, then I believe that what I hear may be real or imaginary but I side with imaginary and wonder if I should go see my shrink.

If I can hear it, and measurements agree that I should be able to hear it, then I believe that what I hear is real and I grab another drink.

If I can't hear it, and measurements suggest I should be able to hear it, then I change up my system.

If I can't hear it, and measurements suggest I shouldn’t be able to hear it, then I grab another drink.

 

[twich54]

I believe your hearing has a drinking problem ......whereas my drinking has a hearing problem !!

 

[Pneumonic]

Nice, I see what you have done here.

If only we could hook them up together; maybe our problems would be solved.

 

[snyderkv]

What would be a non measurable factor? Faith?

IMO If we all "trust our ears" then we should trust the OP that there is no difference IMO. Infact, he's most familiar with his Onkyo already so any changes should be immediate IMO

To the OP, if you never listen to SPL levels that require the extra watts, then get your money back. Although it's good to have headroom when you need it, perhaps for a party, wedding or whatever, if you can't justify the cost, then get your money back and take your wife out for dinner and buy her some shoes. That will be money well spent IMO

ps. I didn't think an Onkyo had the current to drive ESLs. I heard of AVRs shutting down or getting hot

 

[Bevensee]

Amplifier measurement is a very complex matter. There are a couple of quite interesting papers on Nelson Pass' homepage. The problem is that most measurements are done with a single (or at most two) tones present at the same time. But this does not properly account for the way various distortion phenomena are perceived by our ear/brain interaction.

Whereas I agree that many people underestimate the power that is required to avoid clipping, this alone does not explain why amplifiers sound so different at low levels. And "lumping" everything into a single distortion parameter does not tell much either. We all know that 2nd and 3rd order distortion is much more difficult to hear than higher order distortion at the same level.

Even Stereophile's measurements does not tell the whole story. They limit themselves to two-tone intermodulation effects. And already there it becomes very difficult to interpret the measurements.

Many of us find many tube amplifiers to sound less harsh at low level than many SS amps. This is often attributed to high-frequency roll-off. But why? There are several tube amps that measure flat to above 50 KHz, so surely high frequency roll-off can not be the reason.

There is one thing I find a bit strange: When an amp sounds clinical, we tend to name it neutral or uncolored. When an amp sounds warm, we tend to name it colored. Could it not be the other way around? That the clinical sound of some SS amps actually is a coloring from various distortion effects? And that the warm sound from a well-designed tube amp below clipping actually is from the lack of this distortion?

As long as we are measuring amplifiers with single or two-tone test signals, I doubt that we will be able to relate all sonic differences to measurements.

 

[Bernard]

If I can hear it, and measurements suggest I shouldn't be able to hear it, then I believe that what I hear may be real or imaginary but I side with imaginary and wonder if I should go see my shrink.

What do you do if your shrink can hear it too?