How so? Research is done in bite sized steps, chipping away at a problem. Dramatic breakthroughs and paradigm shifts are rare.
BTW ALL the is talk of hi-rez this and that? It all leads straight to the mediocrity closed loop that you guys are stuck in (except JC of course). I hammer and hammer you guys. Basically I get back "it doesn't exist. you don't understand!" then a few pages go by.... then "it does exist but it doesn't matter"...F me man!
So I just went back to work for a few, lurking at your crazy train posts. Then the ONLY post of wisdom was JC talking about tubes. HE was actually looking back at all the work hes has done and comparing it to tube designs. THE ONLY grounded one in the bunch (except me of course).
So I just went back to work for a few, lurking at your crazy train posts. Then the ONLY post of wisdom was JC talking about tubes. HE was actually looking back at all the work hes has done and comparing it to tube designs. THE ONLY grounded one in the bunch (except me of course).
Anyone that has a list of opamps that were designed specifically with audio in mind, and that were validated by the manufacturer exactly for this use? I mean, not opamps designed by specs for some other apllications and that eventually found some use in audio too?
Mark, can we have some anchor to the cymbals sound? I mean, my expectation on how they should sound varies, depending on whether you're producing a record of a trash/punk band or a jazz quartet. I guess it would even influence the mic choice.
So how about producing a few mixes where everything is similar except the cymbals? If we won't learn anything about "distortion", then at least we would get wiser about mixing. Win win.
So how about producing a few mixes where everything is similar except the cymbals? If we won't learn anything about "distortion", then at least we would get wiser about mixing. Win win.
It's just that a cymbal is a single instrument to intimately learn the sound of which has a wide bandwidth, so you can learn what it sounds like in multiple frequency ranges. This can be done by using a parametric EQ to emphasize and study the sound at different frequencies. Once you deep learn how your reference cymbal sounds,and come back to it regularly to refresh your memory of it, it's easier to recognize any departure from what is normal for it.
To make a rough analogy that might help a little, maybe its sort of like knowing somebody all your life and knowing their face and expressions very well, and furthermore, the person has very detailed face with lines, wrinkles, bumps, moles, warts, etc., you have learned to notice if someone photoshops any of those features away. You can from memory check each one. On other other hand, it would be far more difficult if you were looking at a crowd scene with heads bobbing around and shifting position. Too much to learn easily, and too easy to get distracted with all the action going on. Much more difficult to see if any subtle alteration has taken place.
I don't attempt to justify this observation with theory, it just seems to work well in practice with cymbals.
So you are saying you never heard hi-rez you liked? What if you did someday? Have you already decided it is physically impossible and will stay that way forever?
Regarding what you are calling "closed loop," are saying there should never be any feedback at all including locally, such as an emitter resistor here or there? If it can ever be okay to do something like that, then you will have approved of at least one type of closed loop. Probably a lot of equipment you like the sound of has some feedback in places, whether you know it or not.
Maybe "unmeasurable" is still too high of a residual level? There are better instruments now that have a low enough residual to show component nonlinearities. One could argue that we're not going to hear such and such minuscule numbers, but remember, these are artificial tests done because they are easy, and they identify some distortion mechanisms, not because we listen to notched sine wave generators.
I'm pretty sure that's not true. I'm pretty sure that the 797 output stage is biased AB, not B. Either that, or the 11mA of bias current just powers the IC package heater LOL!
Which problems? I have no problems with them. They are good for different purposes. Sometimes it is better without them, sometimes with them, sometimes it does not matter which one to use, sometimes it matters a lot.
?? The software is free! Takes in wave files, adds the specified distortion (not enough varieties yet) and makes an A/B/X test out of them. You play it back through whatever audio system you can use with your PC. A USB DAC or even SPDIF in many cases.
I guess you got the QA401 audio analyzer confused with the software which is only connected by authorship. The QA401 is a real value product actually as well.
IC's discrete transistors, vacuum tubes. They can all get to the same place. I think its an understanding of the goal and the limitations of the devices you are using. None are intrinsically better that others. Current IC designs are able to do things that are impossible discretely. And no transistor can swing 5KV or deliver 50 KW of RF power. I think this is more about knowing the stuff you have to work with. JC has a repertory of designs that have worked well for him. Nelson Pass does. I do and many others here do. None are intrinsically better.
I just spent part of the day swapping opamps in a low distortion oscillator looking for improvements. The results were not obvious and it demonstrated that a simple opamp roll can easily backfire. (There was a 30 MHz oscillation only at an opamp input with certain opamps in specific places). In other words you can't claim a particular opamp will sound a certain way without including every other aspect of the circuit.
I straddle the objective and the emotional sides and have a constant sense of being adrift because of it. I would like to know if there are objective tests or aspects that relate to either higher accuracy in sound reproduction or a more universal "better" sound. One constant problem is coming to grips with the reality that sometimes the real thing was not that beautiful or sweet sounding. Evaluating audio playback based on the single ended - open loop judgement of listening to recorded sounds is a minefield. You can arrive at a truth for yourself but can't extend it to anyone else. And you can't claim its accurate. You can't know what real and what suggestive issues are coloring your reaction. There is no basis. Ultimately you end up in arguments like the difference in the sound of gold QUAD ESL grilles vs. black QUAD ESL grills. (There really were people who believed the gold anodize sounded warmer).
I just spent part of the day swapping opamps in a low distortion oscillator looking for improvements. The results were not obvious and it demonstrated that a simple opamp roll can easily backfire. (There was a 30 MHz oscillation only at an opamp input with certain opamps in specific places). In other words you can't claim a particular opamp will sound a certain way without including every other aspect of the circuit.
I straddle the objective and the emotional sides and have a constant sense of being adrift because of it. I would like to know if there are objective tests or aspects that relate to either higher accuracy in sound reproduction or a more universal "better" sound. One constant problem is coming to grips with the reality that sometimes the real thing was not that beautiful or sweet sounding. Evaluating audio playback based on the single ended - open loop judgement of listening to recorded sounds is a minefield. You can arrive at a truth for yourself but can't extend it to anyone else. And you can't claim its accurate. You can't know what real and what suggestive issues are coloring your reaction. There is no basis. Ultimately you end up in arguments like the difference in the sound of gold QUAD ESL grilles vs. black QUAD ESL grills. (There really were people who believed the gold anodize sounded warmer).
Right. Did try it out eventually. Don't think it works for my current needs, unfortunately. Thanks, though.
That seems sensible. However, sometimes opamps have been observed to often bring some characteristic sound associated with the presence of the particular opamp. in such a case, that's not to say the opamp is the primary cause of some audible effect associated with it. To take an extreme example, guitar distortion pedals with diodes in the opamp feedback path seem to vary in sound quality more when opamps are swapped than when diode types (e.g. germanium, silicon, LED, MOSFET body) are swapped, even though the presence of the diodes may be the primary cause of the opamp associated characteristic sound occurring in the first place. (Changing diode types may change the output signal level by some millivolts or volts, however, but that's not the effect I am referring to in reference to the presence of a characteristic sound more associated with the opamps.)
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Wow, hero worship or what🙂
So all other views that differ from JC's are to be ignored as THD and noise... I love an open discussion, of course JC loves to go on about things from 30-40 years ago!😀
I find this silly beyond belief. We are dealing with electrical signals. What would be so specific about audio? Music can be magical, but once transformed into an electrical signal, that signal behaves like all signals do.
I have never been able to not relate an audible difference to measurements. But, I may have stumped myself into hearing immunity
by listening for differences blind.What most people define as distortion is any difference between the input signal and output signal apart from:john curl said:
1. random noise
2. simple amplification (i.e. multiplying by a complex number)
3. bandwidth limiting
4. hum etc.
I have probably missed something, but I hope you get the picture?
What is your definition? Something undefinable which opamps do to the music?
That is a very sweeping statement. In one sense it is true, because all human artifacts are imperfect, but I guess that is not what you had in mind. IC opamps have particular issues, such a thermal coupling/feedback, but these are known about. On the other hand, they have matched transistors which you can't get in discrete opamps - unless you use a chip, but at what number of transistors on a chip does the magic escape?
So all we need to do is open our ears? Or would it help if we do what you do and open our eyes too?
But do they sound different? And is that difference real distortion, or just one of the non-distortion changes I mentioned above?Markw4 said:
Who are these people? I can imagine a raw graduate believing that his equipment can measure everything of interest, but most of us are not raw graduates.
It may surprise some people to hear that general relativity and spherically symmetric solutions to the field equations (with or without angular momentum) are somewhat harder to do and interpret than low frequency low power electronics like audio. It is a logical fallacy to say "clever people don't know everything about difficult stuff, therefore other people don't know anything about easier stuff in a largely unrelated field of study".
Or perhaps you could tell us first Mr. Curl what ___ amps are by their nature perfect?
Would this version make you agree to then?
"We're talking opamps that are not appropriate and acceptable on a non EE basis, and perhaps even not designed for and/or not commonly used for audio applications. It's that complicated".
George
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