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2nd order harmonics, whats there and whats not?? (Read 859 times)
Eleveniseven
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2nd order harmonics, whats there and whats not??
10/06/10 at 02:09:55
 
ok...i need some explanation.
I read and read on the benefits of SET amps, and admittedly, im very interested and i want to get into this stuff. but in the meantime, while im saving my little fortune to buy my upcoming hifi setup, i am wondering something.
i understand that with a SET amp, the second order harmonics are not cancelled, as they are with pushpull, or  solid state amps, right?
if this is indeed true, what am i listening for? in a reproduction situation, i am expecting my amplifier to reproduce as accurately as possible, what i give it, nothing more, nothing less...right?
if this said harmonic content is present on the recording, would not any amplifier reproduce it? or does the SET stuff add something that isnt there? or does the SS stuff take away stuff that is there?
i think i am missing something here, that either i am too dumb to understand, or has been grossly misunderstood.
thanks for your patience, i hope someone can enlighten me.
on a side note, i am a guitar player, and have heard the differences between SET amps, solid state and so on, i get that. but in that regard, we are referring to a string vibration that is the source of these harmonics, where they actually are occurring, not being produced. where anything but the SET type amplifier, negates this sound and does not reproduce it.
what am i missing?
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Steve Deckert
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Re: 2nd order harmonics, whats there and whats not??
Reply #1 - 10/07/10 at 04:17:34
 
Accuracy is a man made term that has nothing to do with how the brain listens to music.  In fact, being a term conceived in the right brain, accuracy can have little influence other than to cloud the perception of music.  Why? Because experiencing music is a function of the Left brain. Trying to use the left brain and right brain at the same time is often to use either with less results.

That said, when man applies the term "accuracy" to music reproduction he is assuming his definition of accuracy is correct and regrettably it is too crude and simplified to be even close. All math and standard practices for designing and measuring amplifiers looks at crude indicators of performance and "accuracy" while overlooking all of the embedded or underlying subtleties hiding in those measurements or beyond those measurements ability to reach.

This is why it is perfectly acceptable practice in the professional world of amplifier design to group both odd and even order distortion in the same camp and why it's also perfectly acceptable to diminish timing cues in the music with negative feedback.

I don't really like the rather simplified and crude application of the word distortion to "harmonics" as in "Even order harmonic distortion".  I'll accept it for "odd order harmonic distortion". The reason is simple;  In nature sounds are richly embedded with even order harmonics. The harmonics are mathematical. They exist to add GREAT complexity to an otherwise simple fundamental note of sound. Put another way, they take a fundamental sound that contains X amount of data and multiplies the data by a factor of thousands. This way the ears of the world can discern massive amounts of information from that sound, an evolution of survival.  

Odd order harmonics on the other hand, which are an artifact of some amplifier designs, are seldom found in nature and therefor sound artificial.

Many people will tell you that SET amps add a tremendous amount of distortion that is not really there in the recording and that solid state amps have some 10 to 100 times less.

The truth is in the crude misuse of the word distortion.  If an analog recording is rich with even order harmonics (things that define the timbre and space of instruments) then an amplifier design that cancels even order harmonic distortion is going to be less adept at reproducing even order harmonics in the recording.  Plus, virtually MOST amps that cancel even order harmonic distortion, ie, push pull topologies, also require negative feedback which destroys timing cues and as a result smears detail and collapses depth of sound stage.

So in summary, the exact opposite of common belief is true: SET amplifiers take away FAR LESS information from the original recording than do push pull or solid state.  It's EASY to hear.  A 3 year old can hear it, and so can you. Why then do most amplifier designers apparently not use their ears?  Because they in fact don't use their ears, instead they use calculators and their eyes to view their scopes until it looks right according to standard schooling in electrical engineering.  Sad, but true.

It's really just that simple   Wink



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Eleveniseven
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Re: 2nd order harmonics, whats there and whats not??
Reply #2 - 10/07/10 at 14:40:40
 
thank you Mr. Deckert for another well written response. I do appreciate the information. I hope you didnt take my question as a negative comment, wasnt intended that way whatsoever.  :)

At the risk of being a little slow, I just want to make sure i indeed understand, if lets say, a piece of recorded music is rich with second order information, if this said music is played through a p/p amp, this information would be cancelled? whereas, with SET it would not, right?
Im dont really need an engineering response, because im not an engineer. but im kind of confused as to why this occurs, how does an amplifier distinguish between a fundamental signal, and harmonic information? in my simple mind, i see electrical signal going in (music), small, going through a transistor or vacuum tube, then coming back out bigger...
obviously there is more going on, that i dont understand. but i dont get how if information is recorded, and is present in the recording, an amp doesnt reproduce it. isnt that the point?
that being said, and having read your response, i see that the SET amplifiers do just that, reproduce whats present.
grr, why all my life and everyone in general wishes to produce things that detract from what we should hear? what was intended to be heard...
Angry
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Steve Deckert
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Re: 2nd order harmonics, whats there and whats not??
Reply #3 - 10/07/10 at 16:54:30
 
Quote:
if lets say, a piece of recorded music is rich with second order information, if this said music is played through a p/p amp, this information would be cancelled? whereas, with SET it would not, right?


Wrong.  It means the SET is more adept at reproducing even order harmonics than Push Pull.  Also, ALL music is rich in harmonics, not just some.

Yes, many non-single ended amps MASK or poison some of what is in the recording.  Now... the SET amp is not perfect either, because it can ever so slightly embellish the even order content.  But it is far better to slightly embellish music (like your room acoustics will also do) than it is to mask or smear music like so many amplifiers do.

There are two reasons why most amps use negative feedback and cancel even order harmonic distortion...  1) Negative feedback masks brightness and detail in the midrange and treble thus making CD's sound smoother.  2) 9 out of 10 people place speakers where they look good (near a wall) rather than where they sound good (out in the room) and therefor can not reproduce a sound stage with 30, 40, 50 feet of depth, so to them the two amp types sound about the same... they hear no penalty.

Let's talk about sound stage depth.  The 3D placement of images in space between and behind your speakers.   Analogy,  driving at night with only your parking lights on lets you see about 6 feet in front of your car.  Driving at night with your headlights on gives you a detailed view that extends way way farther.

Steve
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Eleveniseven
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Re: 2nd order harmonics, whats there and whats not??
Reply #4 - 10/07/10 at 19:09:07
 
excellent, thank you for helping me understand these important things.
i am about to bust at the seams to get this rig built, just still saving.
i am planning to run a pair of your ERR's, unless when the time comes, you steer me differently. im plagued with a very very small room for listening. hopefully as the time draws near, i can schedule a demo with you. i just live over in indiana, in the Terre Haute area.
thanks again for all of your input and patience in answering these things.
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