Global Feedback - A huge benefit for audio

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#701
billshurv said:
I cannot resist reposting this

The oldies are the best.

In light of the rising frequency of human/grizzly bear conflicts, the Montana Department of Fish and Game is advising hikers, hunters, and fishermen to take extra precautions and keep alert for bears while in the field. We advise that outdoorsmen wear noisy little bells on their clothing so as not to startle the bears that aren't expecting them. We also advise outdoorsmen to carry pepper spray with them in case of an encounter with a bear. It is also a good idea to watch out for fresh signs of bear activity. Outdoorsmen should recognize the difference between black bear and grizzly bear poop. Black bear poop is smaller and contains a lot of berry seeds and squirrel fur. Grizzly bear poop has little bells in it and smells like pepper spray.
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Ref just scraping by, it was worse than that if the sums on rates of mutation
are correct.

I read once that australia was lush forest until man arrived and decided grassland was better for hunting so burned it down. As this was written by a white man I am not taking this as gospel...
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😀😀😀 Best laugh I've had all month. Thanks, I needed that!

Mike
 
#702
atmasphere said:
logic?



None needed. Knowing how loud the darn thing is going to be pretty helpful. Imagine not being able to distinguish volume??


As I said.


Actually I took several classes on the subject. I am claiming both, since man is in fact the most dangerous predator on the planet.


4KHz peak: well within birdsong range and also some of those peaks I pointed out earlier. You've not refuted anything I've mentioned on this topic so far, despite calling BS on it.

Folks, I know that my comments on brightness are not popular. But drop the popularity thing for a moment because its a made up story. We all want our brainchildren to be perfect, but its not a perfect world and our efforts at audio won't be either. But we can make them better even if not perfect. However the first step will be to recognize that there is a problem. You can shoot me if you want but I am only the messenger. The fact is I want SS and feedback to work (and by that I mean no coloration). Sure, I make tube amps. But if you think that I'm married to them or something then you don't understand who I am. The reason I make tube amps is I've not been able to make solid state amps that don't sound like solid state amps. All amps, tube or solid state, should just sound like real music make no mistake.
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If I understand correctly, you are talking about weighting distortion from a psychoacoustic point of view.

Folk keep trying to do this and there are some standards.

These people sell instruments to broadcasters and manufacturers, so they have skin in the game, but nonetheless have to produce useful goods for their customers.

http://www.lindos.co.uk/test_and_measurement/SOURCE=Articles/SOURCE=Articles|VIEW=full|id=5

http://www.lindos.co.uk/test_and_measurement/SOURCE=Articles/SOURCE=Articles|VIEW=full|id=10

Keith Howard on Gedlee mertic:

https://www.google.com/url?sa=t&rct...t7TIBw&usg=AFQjCNFGCM3Nkz5ALkMX-Z-06TxyyQFCUA

Gedlee's response:

http://www.gedlee.com/downloads/Comments on howard.pdf

Gedlee distortion page:

Perception
 
#704
atmasphere said:
That's true. We have had some distortion tests done by magazines over the years, unfortunately most of them have had troubles doing the test properly as the amplifiers have a floating output; neither side should be tied to ground
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Ralph is this really happening at the reviews? That would be one galloping incompetence - any $ 100 sound card does balanced/floating measurements. Funny.

Anyway, it would not stop you to publish comprehensive measurements on your website. Why don't you do that? You obviously have product pride.
Jan
 
#705
Regarding measurements I find it amusing that class D is measured with filters the renders measurements at best meaningless ans at worst manipulated to show better than actual results.

The I also find it amusing that the otl is chased for having poor data, I find that kind of obvious, for me it's a clear manifest the data says nothing about performance, just came from a visit where the same speaker was played ps a few different amplifiers, solid state Class AB, class D, push pull tube and single ended tube.
Most sounded good, but the single ended tube was outstanding in sheer transparency and naturalness. Speakers were not there and music filled the room in a beautiful and natural way. Now you can callt the SETs effects boxes, but if the effect takes me closer to the artist I'll take it any day.
 
#706
AKSA said:
- by Vladimir K in Tashkent

Thank you very much for your worthy comments.......! 😎

Hugh
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Thanks, Hugh, for commenting my humble opinion. There is similar discussion at vegalab forum, maybe with 100 times more posts than here (so, perspective is endless). But, as always, without clear technical outcome. In my opinion, designer of audio equipment must be not only a qualified engineer, but also highly experienced in acoustical expertise (like probably early Mark Levinson).
 
#707
Guys I can't fathom why we still discuss this bright-not bright stuff! It's all so basic, especially for all of those who claim that they understand perception.

If you live tube amps, any ss amp sounds bright. If you live ss amps, any tube amp sounds dull. It's called 'relative'.

Can we let this go now please?

Jan
 
#708
MiiB said:
Regarding measurements I find it amusing that class D is measured with filters the renders measurements at best meaningless ans at worst manipulated to show better than actual results.
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This is a nice example of how folklore gets created. One guy, not hindered by facts, suggests that class D is measured in a way to hide it's performance. Two pages later, helped out by some expectation bias, it is presented as fact. Isn't Group Dynamics fascinating!

an
 
#709
atmasphere said:
I run a recording studio so I deal with this all the time. When I play back recordings I have made on various systems I can tell if they are bright nor not right away. It is helpful to make your own recordings and then produce them so you indeed do have a metric. But just in case you are not aware of this fact, the single most often made complaint against solid state amplifiers in general is that they are bright.
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Generally yes, SS amps are "bright" and they tire during long listening. However, there are also a lot of SS amps with "dark" sound. The last feature could be pertinent to "overcorrected" GNFB schematics. At the same time, there is a way of approaching "correct" sound with SS designs (due to very high speed at GNFB loop, like in Soulution amps and some others).
 
#711
#712
This Bimo chart shows to us unfiltered THD components mesurements of some very good A/B class amp up to ~ 6.5Mhz range ,

I wonder how is possible in the present modern 21 century that some class D amp can not be measured excited at full power to show us Unfiltered both THD components results and RF switching carrier components results up to same ~6,5 Mhz range or even wider ??? ,
but Only filtered results up to 20 Khz ? :scratch2:
 

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#713
jan.didden said:
Guys I can't fathom why we still discuss this bright-not bright stuff! It's all so basic, especially for all of those who claim that they understand perception.

If you live tube amps, any ss amp sounds bright. If you live ss amps, any tube amp sounds dull. It's called 'relative'.
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Why did Gordon Holt claim exactly the opposite? And Holt's claim actually makes sense, since most dynamic speakers have a rising impedance in the treble and tube amps tend to have higher output impedances than ss.

Are there any data supporting the notion that if a low distortion tube amp and a low distortion ss amp have the same frequency response over the audible band, they will sound any different from one another when tested ears-only? Richard Clark's data would suggest not.
 
#714
SY said:
Are there any data supporting the notion that if a low distortion tube amp and a low distortion ss amp have the same frequency response over the audible band, they will sound any different from one another when tested ears-only? Richard Clark's data would suggest not.
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They will sound different without any doubt, since even the same amp, will sound different if some passive parts are replaced in it by same value parts of different kind (resistor in the GNFB divider, for instance, or kind of lytics in PS).
 
#716
banat said:
This Bimo chart shows to us unfiltered THD components mesurements of some very good A/B class amp up to ~ 6.5Mhz range ,

I wonder how is possible in the present modern 21 century that some class D amp can not be measured excited at full power to show us Unfiltered both THD components results and RF switching carrier components results up to same ~6,5 Mhz range or even wider ??? ,
but Only filtered results up to 20 Khz ? :scratch2:
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This can only be done (IMO) using fixed frequency Class D amplifiers. However these are often nowhere near the THD performance levels of a standard class A/B.

You do have a filter on the "THD measurement", you have a 9kHz BW as far as I can tell.

\\\Jens
 
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#717
banat said:
This Bimo chart shows to us unfiltered THD components mesurements of some very good A/B class amp up to ~ 6.5Mhz range ,

I wonder how is possible in the present modern 21 century that some class D amp can not be measured excited at full power to show us Unfiltered both THD components results and RF switching carrier components results up to same ~6,5 Mhz range or even wider ??? ,
but Only filtered results up to 20 Khz ? :scratch2:
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This is a SIMULATION. You can do ANYTHING in simulation, measure your class D till 10GHz if you want. 😉

Ja
 
#720
jan.didden said:
I am convinced that if I don't tell you which is which, you will not be able to hear a difference.
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You have a lousy system and you're deaf if you can't hear such a huge difference. Why, even my wife, who doesn't care about audio and is deaf in one ear, was able to hear the difference from her usual spot in the kitchen. And that was from a kitchen several hundred miles away, using her cell phone, pressed against her deaf ear.

Some of us can hear differences, some can't. I feel very sorry for you.
 
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