What is wrong with op-amps?

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You may have an explanation of why that you believe and find plausible. You can't know what role your System 1 plays in "why," because it is unobservable by your concision awareness. You understand that, right?

But to avoid cognitive dissonance, System 2 will 'generate' a fitting explanation, and in that sense we 'know why' although we have no way to know it that is the real reason; it's just a convenient reason that fits our world view.

Did I get that right Mark ;).

Jan
 
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You may have an explanation of why that you believe and find plausible. You can't know what role your System 1 plays in "why," because it is unobservable by your concision awareness. You understand that, right?

Well if you mean 'I can't afford to replace 1000LPs with CD equivalents' and 'I can't afford to replace all these nice lenses' then yes.

I did abandon film when the quality from the average minilab got so poor I couldn't tell if it was taken on my SLR or a happy snappy. Then I abandoned photography for 4 or 5 years until I could afford back in with a digital to learn on. Still learning!

As I spent thick end of a decade in a fairly advanced state of disassociation I may not match the norm on some of this (then again I might). These days I am happy there is only one person in my head (or out of it).
 
Jan, the way it has been described in the literature, System 1 does most or all the the generation of explanation. If found plausible by System 2 (which is the default), it is accepted and believed. In the less frequent case, if found implausible by System 2, then System 1 is put back to work constructing another explanation until System 2 finds some explanation plausible enough.

However, it should be noted that the above way of thinking does not apply to things solving 17 x 24 = x. For that System 2 must be activated. (Except perhaps for certain very unusual people, where the answer pops into conscious awareness immediately. In that case, their System 1 has rare and poorly understood computational capabilities.)

That being said, System 2 is lazy and tires easily. Whereas System 1 is tireless and always does more than is asked of it. That is, it retrieves more associations than the precise number required to answer a specific question.

Also, it may be useful to note that whenever we simply "see", or just know, that something is true, that is a sign of System 1 at work.
 
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Shown are three of the opamp test cards. Each holds two circuits. Design of PC mostly from Marce. The odd one out is a Marsh headphone amplifier. Tomorrow I should have the case finished. Then the guys here can listen and report their preferences.
 

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Bonsai, 50ns [risetime]? I was only hoping for 10us! However, we know that above perhaps 5V/us, for a low voltage preamp, TIM is not a dominant mechanism most of the time, but PIM or FM, or differential phase might well be.
Here is what Nelson Pass was able to do in 1979 using MPS6571 transistors (fT = 175 MHz), in the Threshold NS-10 preamplifier.

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If we were to have hi fi that had 1% THD for the chain we would be happy as we would not be able to hear it ( I assume ideal harmonics where the fifth is where it would be in music or however you would want to say it ). This is the whole chain. Most people here own a system of about 5% THD at best, microphones are not very specail in this. Some are even liked as they have the right distortion type to suit a job. Often very low distortion devices sound good in other ways ( GBP is an easier one to name as is noise ). Whilst that is great I suspect many mistake lets say output impedance for distortion ( SE valve designs come to mind with a damping factor of 3 if lucky ). Truely it can be the very worst distortion I know of which is amplitude distortion. What these discussions remind me of is vitimins and how they work. Most hi fi working in the middle volume range might do the 1% target. KEF LS50 would help. The BBC radio 3 on a good day with a Hypex power amp module and the LS50's might do 2% THD at 100 dB+ in the room.
 
If we were to have hi fi that had 1% THD for the chain we would be happy as we would not be able to hear it

Please speak for yourself. Let Bob Ludwig and others decide what works for them.

Also, there have been numerous observations that not all THD is equally objectionable, and that perhaps we need a more detailed metric to capture what THD matters more to some people, and what THD may matter less.

Finally, when you say "we" without any qualification, and THD without any qualification, maybe you are talking about yourself, or your perception of what would be adequate for most people. If so, fine. Please say it that way though.
 
Shown are three of the opamp test cards. Each holds two circuits. Design of PC mostly from Marce. The odd one out is a Marsh headphone amplifier. Tomorrow I should have the case finished. Then the guys here can listen and report their preferences.

I wonder if Mooly wouldn't be a good test subject for this. He has proven himself a serious listener willing to expend effort to produce the most detailed observations he can.
 
Please speak for yourself. Let Bob Ludwig and others decide what works for them.

Also, there have been numerous observations that not all THD is equally objectionable, and that perhaps we need a more detailed metric to capture what THD matters more to some people, and what THD may matter less.

Finally, when you say "we" without any qualification, and THD without any qualification, maybe you are talking about yourself, or your perception of what would be adequate for most people. If so, fine. Please say it that way though.

Give it some thought. If a gambling man I would bet you your hifi is more than I%. If not the recordings you have are not available to me. If we have 5 or 2% between live sound to our ears then taking the last 0.1% out of a phono amp is not really doing much. Almost certinly it will do harm if the bigger picture isn't respected. That could be a bandwith that is too large or too small as a simple example. One that is just right can take months to find. It could be 45 kHz, it might be awful at 35 kHz and equally awful at as wide as possible. Piano sounds wrong with 35 kHz you might find! This seems to be waveform shape and not that we can hear 35 kHz. Even old people hear like this! If only having 12 kHz of hearing that is not due to ear damage then wave shape still can be heard. The trailing edge is more complex and is what standard thoughts on hi fi more reflect.
 
Give it some thought. If a gambling man I would bet you your hifi is more than I%. If not the recordings you have are not available to me. If we have 5 or 2% between live sound to our ears then taking the last 0.1% out of a phono amp is not really doing much. Almost certinly it will do harm if the bigger picture isn't respected. That could be a bandwith that is too large or too small as a simple example. One that is just right can take months to find. It could be 45 kHz, it might be awful at 35 kHz and equally awful at as wide as possible. Piano sounds wrong with 35 kHz you might find! This seems to be waveform shape and not that we can hear 35 kHz. Even old people hear like this! If only having 12 kHz of hearing that is not due to ear damage then wave shape still can be heard. The trailing edge is more complex and is what standard thoughts on hi fi more reflect.

I have given it much thought already, and very carefully considered thought at that. The distortion is my amplifier is less than in my speakers, but I can still hear the amplifier distortion slightly. I can also hear other sources of distortion much smaller than what the speakers produce. It is higher order harmonic distortion that is more objectionable, and my speakers produce a lot more low order. When you lump it all together as though it is all the same, you are ignoring a lot of research and empirical findings. Do your homework, and don't advocate moving us backwards, would be my point of view. We need to keep learning more and keep moving forward to keep improving audio. No reason to go back in the direction of the dark ages.

Again, philosophical reasoning is no substitute for science and the scientific method.
 
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I don't think you can hear it. What you hear is all the factors. I agree that if something work universally better we should be happy. When the VW Golf Gti came out I asked what was it's really big deal. My friend said " If she can drive your granny can get into a Gti and drive it without a second thought ". When I drove one I thought it was slow. It isn't as we all know. What it has is a good balance of virtues. The torque being what granny would like. This is how we keep everyone happy.
 
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