S
seanconnolly
Hi,
Nonsense. Amplifiers are not fully specified, they are very poorly
specified, and simplistic similar specifications don't tell you squat.
rgds, sreten.
It's an interesting exercise, accurately simulating in Spice how amplifiers behave in less than ideal circumstances, and it's "frighteningly" easy to provoke conventional designs to generate momentary distortion artifacts in the output, from various causes - what's perhaps more remarkable is that most amplifiers sound OK most of the time, considering how borderline their "robustness" is ...
The problem is that not many "audiophiles" are engineers, or evidently have much of an understanding of electronics.
It's physics guys. Not black magic. It seems that the only measurements people here are capable of comprehending are the usual figures provided by manufacturers (gain, THD blah blah). Different components (and different PCB layouts) will have different characteristics.
In an ideal world, you could make two amps with different topologies, with the SAME MEASRUEMENTS that sound the same. This is because there are more factors to determine what comes out at the end of an amplifier than what have been mentioned on most audio forums.
This is actually true even in the real world. If you designed two different amps that somehow had the same measurements (there is more to electronics than THD), they would sound the same. It's kinda logical.
It's physics guys. Not black magic. It seems that the only measurements people here are capable of comprehending are the usual figures provided by manufacturers (gain, THD blah blah). Different components (and different PCB layouts) will have different characteristics.
In an ideal world, you could make two amps with different topologies, with the SAME MEASRUEMENTS that sound the same. This is because there are more factors to determine what comes out at the end of an amplifier than what have been mentioned on most audio forums.
This is actually true even in the real world. If you designed two different amps that somehow had the same measurements (there is more to electronics than THD), they would sound the same. It's kinda logical.
That, amplified with confirmation bias ("I read what I believe"). Once you have established your position, an engineer telling you you are wrong just makes you believe even more strongly.
The behavior of even "just" an audio amplifier is far too complex to fully characterize with some numbers.
As an experienced electrical engineer, I understand that.
You appear to imply that audio amplifiers are complex in the grand scheme of electronics... This is most certainly not the case.
Any electronic device is capable of being characterised in full by some numbers. As an experienced electrical engineer, you should know that. And as I say, it's not black magic. It's physics. There's nothing special about audio circuits, it's just an application that people seem to think is special or different from "normal" electronics.
Every darn thing in electronics is to do with "some numbers".
But how much experience and education in cognitive perception do you have? We can measure and model a heck of a lot - but not much of that actually makes for audible differences.
I'm not an audiophile. My setup is Tannoy Mercury V1i speakers, with a LM3886/LME49720 composite amp, with the whole lot driven from a PCM2707 based USB DAC.
Laugh you may, but it's fine for me.
But that's completely irrelevant. My point is that the statement of amplifier "measurements" not having any true correlation to sound quality is totally false. Any differences in sound quality will be to do with a measurable characteristic of the amp. It's just that these things in particular are not usually measured (whatever they may be).
Electrons are electrons, whether they are flowing through a voice coil or a vibrator.
Laugh you may, but it's fine for me.
But that's completely irrelevant. My point is that the statement of amplifier "measurements" not having any true correlation to sound quality is totally false. Any differences in sound quality will be to do with a measurable characteristic of the amp. It's just that these things in particular are not usually measured (whatever they may be).
Electrons are electrons, whether they are flowing through a voice coil or a vibrator.
Thanks to SY for my first hearty chuckle of the day -- and I really needed it.
Back to my conversation with Sheldon : I don't think any poster here has written that amplifier measurements don't have true correlation to sound quality.
What has been said is that amplifiers are too simply specified . . . The measurement of power and THD, for example, do not go far enough.
Electrons are electrons, but what happens to them in the circuitry of different electronic audio devices can make the difference between a great blind date and one that gets left at a tavern to play 301 all by herself.
I hope this clears things up . . . Now excuse me -- gotta put some cases of my fave new IPA in the snowdrift out back.
Back to my conversation with Sheldon : I don't think any poster here has written that amplifier measurements don't have true correlation to sound quality.
What has been said is that amplifiers are too simply specified . . . The measurement of power and THD, for example, do not go far enough.
Electrons are electrons, but what happens to them in the circuitry of different electronic audio devices can make the difference between a great blind date and one that gets left at a tavern to play 301 all by herself.
I hope this clears things up . . . Now excuse me -- gotta put some cases of my fave new IPA in the snowdrift out back.
This is what I'm getting at. But from what I see all too often, this sense of logic is a little lost on some audiophiles.
While the latter is true (hopefully sometime in the future), the fact that we have very few, and see even less, measurements of amplifiers under real use, means we do not yet have a complete set of measures to be able to quantify the performance of any amplifier. Further a set of proper scientic studies that correlate what the ear/brain perceives and what we do measure, the 1st statement is patentendly false.
dave
PS: the 2707 is a device of relativily low quality, that is the next thing i would upgrade in your system.
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