Ticknpop, you probably know more about what Constellation has built than I do, but I think you have it approximately right. I personally had to supply (for a price) the input devices for the Orion from my personal stock of jfets. They just asked me last night for more! '-) However, my 2SK146's and 2SJ73's is now more limited, and any following devices (if they really want them), will cost them at least twice as much as the first batch. And yes, the Perseus and the Orion are essentially the same internally.
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Now that some people have responded to this AES paper 'Measurement of a Neglected Circuit Characteristic' for better or lesser, I would like to point out something that seems to be ignored by just about everybody.
Here is page 3 where I have underlined something that appears to be most important: Low open loop bandwidth might be a contributor to 'memory distortion'. This could be the key to improved listening quality, above and beyond local heating in passive and active components. That is what I want to look for.
Here is page 3 where I have underlined something that appears to be most important: Low open loop bandwidth might be a contributor to 'memory distortion'. This could be the key to improved listening quality, above and beyond local heating in passive and active components. That is what I want to look for.
Attachments
Important in that it shows just how pernicious Otala's "framing" has been
and Ironic just one post separated from Scott's mentioning the AD796 ATE application - and the whole analysis that should bring to mind of most well educated Analog EE
ATE settling time analysis has been done to death in many app notes, textbooks, Williams, Pease to mention a few better known
a start for the search impaired: http://www.edn.com/design/analog/4363562/Measuring--wideband-amplifier--settling--time
just the titles, dates of the references should clue you in to the long history and high resolution achived
and Ironic just one post separated from Scott's mentioning the AD796 ATE application - and the whole analysis that should bring to mind of most well educated Analog EE
ATE settling time analysis has been done to death in many app notes, textbooks, Williams, Pease to mention a few better known
a start for the search impaired: http://www.edn.com/design/analog/4363562/Measuring--wideband-amplifier--settling--time
just the titles, dates of the references should clue you in to the long history and high resolution achived
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Unfortunately, 'Settling Time' is not related to what 'memory distortion' measures. There is a factor of perhaps 10000 difference in time scale. i.e. 10ms/div compared to 1uS/div or much less. They are completely separate measurements because of this.
ATE. Automatic Test Equipment usually. Typically semi test or volume mfr test systems but also military systems. Think pricetags that even audiophiles have trouble with.
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10 ms/100 rad/s ~ 16 Hz, hearing threshold in quiet >70 dB SPL
but don't let mere inaudibility of their measured 'Commercial Amplifier' -60 dB 'Memory Distortion' be the sole argument
although it is fun to put some numbers on the 3 Vrms output, < 3mV "memory distortion" 'scope shot from the paper
you also need an appreciation of low frequency human hearing 'threshold of hearing in quiet' - which rises pretty much 1 decade/decade below ~ 200 Hz (200 Hz would be ~ 1 ms time constant)
suppose the amp, speakers were capable of 120 dB SPL at a full 30 Vrms - then the shown 'memory distortion' step would be ~40 dB SPL - which couldn't be heard on its own in a anechoic chamber with minutes of accommodation for the ears to relax enough to hear your pulse, blood flow noise - given its low frequency content - by a margin of 30 dB!
my main argument however is still that 'memory free' response is readily available in high loop gain amplifiers with only minor attention to diff pair dissipation (need I again mention bootstrap cascode) and quality feedback components
you are amazingly uniformed if you think Industrial Scientific Measurement oriented designers haven't categorized ADC, DAC, analog signal chains on ms to seconds time scales - to the point that those 1ppm, 18, 20 bit, ect. settling times are quite sufficient characterizations to "those skilled in the arts" - and they know when to switch to tempco, thermocouple, 1/f noise explainations for appropriate time scales
nothing is mysterious is happening at 10 ms in those systems:
The 20-Bit DAC Is the Easiest Part of a 1-ppm-Accurate Precision Voltage Source | Analog Devices
my baseline for that is my last pro gig, which was designing force and motion control instrumentation including strain gage force sensor amplifiers with gains up to 4000x, looking at them with 16 bit 16 ks/s/channel ADC, characterizing them into the noise floor with 10 Hz 6 pole digital filters
it was easy to see sub lsb stepping drifts from turn on thermal transients, even creep in the plastic backed strain gage foils - at minutes to seconds time scales
but don't let mere inaudibility of their measured 'Commercial Amplifier' -60 dB 'Memory Distortion' be the sole argument
although it is fun to put some numbers on the 3 Vrms output, < 3mV "memory distortion" 'scope shot from the paper
you also need an appreciation of low frequency human hearing 'threshold of hearing in quiet' - which rises pretty much 1 decade/decade below ~ 200 Hz (200 Hz would be ~ 1 ms time constant)
suppose the amp, speakers were capable of 120 dB SPL at a full 30 Vrms - then the shown 'memory distortion' step would be ~40 dB SPL - which couldn't be heard on its own in a anechoic chamber with minutes of accommodation for the ears to relax enough to hear your pulse, blood flow noise - given its low frequency content - by a margin of 30 dB!
my main argument however is still that 'memory free' response is readily available in high loop gain amplifiers with only minor attention to diff pair dissipation (need I again mention bootstrap cascode) and quality feedback components
you are amazingly uniformed if you think Industrial Scientific Measurement oriented designers haven't categorized ADC, DAC, analog signal chains on ms to seconds time scales - to the point that those 1ppm, 18, 20 bit, ect. settling times are quite sufficient characterizations to "those skilled in the arts" - and they know when to switch to tempco, thermocouple, 1/f noise explainations for appropriate time scales
nothing is mysterious is happening at 10 ms in those systems:
The 20-Bit DAC Is the Easiest Part of a 1-ppm-Accurate Precision Voltage Source | Analog Devices
my baseline for that is my last pro gig, which was designing force and motion control instrumentation including strain gage force sensor amplifiers with gains up to 4000x, looking at them with 16 bit 16 ks/s/channel ADC, characterizing them into the noise floor with 10 Hz 6 pole digital filters
it was easy to see sub lsb stepping drifts from turn on thermal transients, even creep in the plastic backed strain gage foils - at minutes to seconds time scales
Well, I am glad that everything is already known. Yet, I might just try to measure something extra anyway. '-)
there's a difference between 'everything' and what is in that paper
sure, just use the (now 20 year evolved) ADC/DAC as mentioned in the paper
some 'audio' types may be fine, but again the ISM market has pushed ADC/
DAC beyond mere audio requirements in the last decade
alternatively try actually addressing any one of my specific arguments with EE or Psychoacoutics knowledge, references, calculations...
sure, just use the (now 20 year evolved) ADC/DAC as mentioned in the paper
some 'audio' types may be fine, but again the ISM market has pushed ADC/
DAC beyond mere audio requirements in the last decade
alternatively try actually addressing any one of my specific arguments with EE or Psychoacoutics knowledge, references, calculations...
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Which is why litho guys like Rob Munnig Schmidt is also into audio.
Intro RMS-Acoustics & Mechatronics
🙂
Patrick
I think most of us came to the conclusion, it is just the same and one and only physics behind that. With some minor reduced requirements, like we do not need DC precision in audio circuits.
Internal mental processes are probably different if using any sort of ABX if compared for example to A/B tests, at least the results were different (as trials in the 1950s/1960s have shown). Therefore experimenters _have_ to incorporate controls to ensure that they are getting correct results. It seems people don´t accommodate to every test protocol to the same degree.
Most of the people "came to the conclusion", that thay should blindly belive in what official science authorities tell them, so they belive that the monkeys are their distant relatives ,they also belive in big bang and other insane stories...
It's not all about, physics,measurements and science (censored and closed as it is now).
In the case of some people on the internet I am not sure the distance is that much...
Problem is with your statement is that most scientists don't 'believe', they accept the model that currently best fits the available data. As Feyman always drilled into his students, you can never prove a theory, only disprove it. Press offices always mangle things of course.
Problem is with your statement is that most scientists don't 'believe', they accept the model that currently best fits the available data. As Feyman always drilled into his students, you can never prove a theory, only disprove it. Press offices always mangle things of course.
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