Waly mentioned "Western Music" and scales used for tuning. Thinking aloud... as you do...
A piano for example is tuned to an equal tempered scale, perfect octaves but the top octaves are "stretched" and sharpened a few cents (because that sounds better to the ear) and the lower bass octaves are flattened for the same reason.
So... an FFT plot of two similar notes a few octaves apart won't line up exactly... that is just the way it is because we like the sound that way.
An FFT plot of an amp reproducing those notes will do what ?????? You have the real notes slightly imperfect (think of say A above middle C at 440hz and top A at 3520hz except it isn't... our expert piano tuner has sharpened it slightly). Still thinking aloud remember... so the amp reproduces 440hz and harmonics (the harmonic distortion of the amp) but also reproduces the actual imperfect notes.
So we have 440hz and the amps distortion producing harmonics at 880hz, 1760hz, 3520hz etc but those low level harmonics now clash with the actual wanted but imperfectly tuned note of top A that is 3520 hz plus a few cents.
Could that go some way to explaning the sonic qualities... the fact that the amp produces "perfect" THD intervals but the wanted notes are (by design) imperfectly tuned.
Time for a beer...
A piano for example is tuned to an equal tempered scale, perfect octaves but the top octaves are "stretched" and sharpened a few cents (because that sounds better to the ear) and the lower bass octaves are flattened for the same reason.
So... an FFT plot of two similar notes a few octaves apart won't line up exactly... that is just the way it is because we like the sound that way.
An FFT plot of an amp reproducing those notes will do what ?????? You have the real notes slightly imperfect (think of say A above middle C at 440hz and top A at 3520hz except it isn't... our expert piano tuner has sharpened it slightly). Still thinking aloud remember... so the amp reproduces 440hz and harmonics (the harmonic distortion of the amp) but also reproduces the actual imperfect notes.
So we have 440hz and the amps distortion producing harmonics at 880hz, 1760hz, 3520hz etc but those low level harmonics now clash with the actual wanted but imperfectly tuned note of top A that is 3520 hz plus a few cents.
Could that go some way to explaning the sonic qualities... the fact that the amp produces "perfect" THD intervals but the wanted notes are (by design) imperfectly tuned.
Time for a beer...
Familiarisation Time Is The Downfall Of ABX Testing.....
So if the ear/brain connection is so hopelessly unreliable and fallible, why is it that everybody can instantly recognise any particular familiar human voice, even after extraordinary time span, and despite masking/distortion/eq when hearing that voice via pretty much any non natural means.
Spend enough time with any particular stereo system, and the voice of that system becomes familiar, and any changes to that system become instantly discernible.
Sighted testing is not invalid.
Dan.
So if the ear/brain connection is so hopelessly unreliable and fallible, why is it that everybody can instantly recognise any particular familiar human voice, even after extraordinary time span, and despite masking/distortion/eq when hearing that voice via pretty much any non natural means.
Spend enough time with any particular stereo system, and the voice of that system becomes familiar, and any changes to that system become instantly discernible.
Sighted testing is not invalid.
Dan.
I would think that both tones already consist of a slew (no pun intended) of harmonics of their own, which after all makes the instrument sound the way it does.
So the additional amplifier harmonics, if large enough, may change the instrument 'color' or character or whatever you want to call it.
jan
So the additional amplifier harmonics, if large enough, may change the instrument 'color' or character or whatever you want to call it.
jan
The eye/brain connection is likewise hugely inaccurate (see Steve's little demonstration a few posts back, as well as thousands of other known optical illusions), yet you can still recognize the face of a friend.
If you need to peek in order to hear it, the change is NOT "instantly discernable." If you need to peek in order to hear it, it's not even audible to you. This is so well established in sensory science that denial transcends the ridiculous.
You can search Stereophile's site for it; if it isn't posted, it will appear in ToC of back issues. Peter van Willensward (sp?) was the author.
A particularly effective technique is to have on hand a selection of "bad" recordings - ones which immediately show their distasteful side when the system is not "on song". One's hearing system is not tolerant of excessive, disturbing distortion, so it immediately does a 'thumbs down' when the "tuning" is just slightly awry.
Yes, probably just like a piano that's, sort of tuned vs. professionally tuned - it just screams at you that there's an issue ...
Yes, the harmonics are what gives every instrument its character. It could go some way to explaining things perhaps.
The brain-ear has evolved for eons to instantly recognise voices, animal sounds, etc. It has NOT evolved to detect an additional 0.002% 3rd in the harmonic structure of a piano note, because there's no survival value in being able to do that. It's really all very straightforward.
jan
You've been given the map; if you're too lazy to follow it in order to educate yourself, that's your choice.
Well I'll be whompulzonked!
A quick check showed fuses are directional when placed in a panel mount style fuse holder. The removable cap provides a bit of heatsinking and the spring pin on the other side doesn't. (Or so it seems.)
A clip in fuse holder shows much less effect.
The test setup was using my ashly test bench power amplifier and an 8 ohm resistor in series with the fuse under test. Looking across the resistor at 250 mA for a 500 mA fast blow fuse showed different distortion depending on direction.
I make no claims that on a properly designed (or even a badly designed) power supply that such an effect can be heard. The effect exists but it ain't much. If I get a chance I will post pictures.
Now to the effect of spinning a magnet above a CD. When ever you have a changing magnet field impressed upon a conductor a current will flow. This energy will become heat. If enough heat is generated this will aneal the metal.
The anealled metal surface becomes much smoother. When preparing tips for a scanning electron microscope the tips are first etched and then anealled. The before and after pictures are quite dramatic.
So there is an off the wall explanation for why gizmo may do something.
However for a reality check anealing is typically done at a temperature around 100 degrees Celsius below the melting point. At lower temperatures the process is much slower.
Now does this result in a more compact file? Fergslash no!
ES
I understand that they have a print magazine where the article appeared. If you want to pursue it without doing the dirty work of searching, you can drop them an email (I think Peter may even be a member here). It would have been about 1990- PvW surveyed a wide range of CD tweaks, and had to do some fancy dancing at the end of the article.
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