I'm not either John or Scott, but if I may, I'd like to add a personal note.
For some years now, I've been playing on and off with op amps and if there's one thing that is common to ALL I have ever heard, it's that they play better music when you add a discrete current output stage. Never mind what the data sheet says.
No big deal, to be sure, a simple pair of say MPSA 06/56 or BC 639/640 will do quite nicely for line level stages from 600 Oh and upwards loads.
It may not measure much better, just a tiny wee bit better, but you have to be stone deaf not to hear the difference.
Pick your class A bias point as required, add say +25% extra and that's it.
The usual groan here is that adding those trannies will reduce the peak to peak voltage of the output by the voltage drops across those trannies, to which I usually ask back: OK, so you WON'T get 24V peak-to-peak, you'll get say 22.6 V peak-to-peak, but do tell, what's your amp's output like with just 6V peak-to-peak? It's probably smoking itself to death, while your speakers have sprung a coil or two.
All that said, I still agree that for the ultimate, discrete can still be better.
DVV, I am glad that you know what I am talking about. The problem with adding a discrete output stage is the additional complexity and added surface area. I would recommend that the manufacturer actually modifies the output stage for higher standing current. At least enough to drive an 'optimum' feedback loop. Today, system design engineers just take the IC and make it drive just about any load. I have seen serious examples of this. IF we were making instrumentation only circuitry, it might be OK, but not hi end audio.
Not really.
In my view, listening to music is a PERSONAL experince. All those tests are important only if you want to create an absolute reference; kids like that, but unfortunately, I haven't been a kid for over 50 years now.
Today, I recognize only one criterium, and that's do I like how it sounds or not? If I do, how much is it? If not, then thank you, but no, thank you.
I am never offended or hurt when people hear my speakers and say that something is wrong with them, I have a ton of measurements to show that they have been made to deliver extreme linearity, 40-18,000 HZ +/-1.5 dB (or, using the more common criteria, 36-22,000 Hz +/- 3 dB) which is about as good as a professional tape machine running ar 15 ips, that the two loudspeakers have been matched to 0.5 dB L->R, blah, blah, blah. I know that they mostly own far less discriminating speakers and that over the years, they have become used to the way they sound and poorly tolerate deviations from their usual.
Ultimately, who cares? They don't live with my speakers, they don't listen to them day in, day out, I do. And to me, their speakers usually sound too bright, too boomy, but always deficient one way or another. And I know that most people don't really want to hear the truth about their own systems.
A piece of unsolicited but friendly advice: forget what the magazines say, just use your ears and learn (if you haven't already) to concentrate on the music. That's where it's at.
John, you are talking about the shoddy way things are done these days. People just don't bother with familiarizing themselves with what they use, Data Sheet is the Holy Book for them. Too bad it's never that simple.
You are right, adding a discrete output stage does cost more, both in money and real estate, but I think you know it's well worth it in the end. Which leaves only the money as the unsurmountable problem for the industry at large. Whomesoever disbelieveth, let him search the Old Scrolls (service schematics of what used to be made in the late 70ies by reputable companies).
It is shocking to some when they hear a fairly reasonable phono RIAA stage, built around an old OP37, or a Middle Earth OP 275, or a more recent AD 829 AN, with a simple current boosting stage, using all of 2 transistors, 2 diodes, 4 resistors and 1 capacitor, total cost $1, or some such. Plus of course some additional development time and above all, the will to do it right.
And Lord be praised, you can adjust the bias to your real world needs!
The first time I encountered op amp problems was when the Dyna PAT-5 was introduced. Despite Gordon Holt's nice review (I heard his sample, and it DID sound pretty good), mine was not so good. I ordered a bag of 100 ICs for the line amp, and installed a pair of high quality TO-99 sockets. After trying all those ICs, only two were significantly better than the mediocre stock ones. This was very discouraging at the time.
A single truthful positive result pretty much eliminates all the negative.
For instance, just because subliminal advertising fails every single ABX so to speak, doesn't mean it's not working, in every single instance!
The test subjects simply can't pinpoint the difference, even if they're actually experiencing it.
Then as soon as someone comes along and can pinpoint the difference, you can throw the filing cabinet of null results out the window.
A large collection indicates nothing. Just saying.
A lot of those tests he linked are parlour tricks anyway, really.
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Yes, I have faith that my ears tell me when I am going forward or backward in audio quality. It really works, (for me).
For example, I listened to 'The Prairie Home Companion' broadcast this weekend, as I normally do. However, this broadcast was different from virtually all the PHC broadcasts I have heard for years, as it was from 1984. Now, I knew it was NOT LIVE, after all, it was recorded 30 years ago. THEN, what did they use for a broadcast medium, analog tape or digital tape?
Before I first listened, I worried about a digital tape playback being used, but when the program came on, it sounded pretty darn good, in fact, in some ways better than usual.
I would predict that they used an analog tape recorder with a Dolby SR noise reduction system.
Now how can I come to this tentative opinion?
First, it lacked something 'digital' about the program.
Second, I did not hear any background noise.
Third, it sounded 'slightly' veiled, actually more than the usual broadcast. I attribute this to a Dolby or DBX noise reduction being used.
Fourth, it sound like it had more EXTENDED bandwidth than usual.
Can I prove my opinion? No, but I bet I am very close to right, based on my past experience.
This is why and how 'I trust my ears'.
For example, I listened to 'The Prairie Home Companion' broadcast this weekend, as I normally do. However, this broadcast was different from virtually all the PHC broadcasts I have heard for years, as it was from 1984. Now, I knew it was NOT LIVE, after all, it was recorded 30 years ago. THEN, what did they use for a broadcast medium, analog tape or digital tape?
Before I first listened, I worried about a digital tape playback being used, but when the program came on, it sounded pretty darn good, in fact, in some ways better than usual.
I would predict that they used an analog tape recorder with a Dolby SR noise reduction system.
Now how can I come to this tentative opinion?
First, it lacked something 'digital' about the program.
Second, I did not hear any background noise.
Third, it sounded 'slightly' veiled, actually more than the usual broadcast. I attribute this to a Dolby or DBX noise reduction being used.
Fourth, it sound like it had more EXTENDED bandwidth than usual.
Can I prove my opinion? No, but I bet I am very close to right, based on my past experience.
This is why and how 'I trust my ears'.
John, have you any idea how illogical and unscientific that is? 
You listened, made a lot of predictions about methodology of the recording and transmission.
You freely accept that you can "prove" none of it, but then say that you bet you are right! Which then proves how clever and skilled you are !
A detractor of your past achievements I am not, but you just seem able to open your mouth wide enough to easily insert an oversized boot whenever you make such pronouncements. Shame.
You listened, made a lot of predictions about methodology of the recording and transmission.
You freely accept that you can "prove" none of it, but then say that you bet you are right! Which then proves how clever and skilled you are !
A detractor of your past achievements I am not, but you just seem able to open your mouth wide enough to easily insert an oversized boot whenever you make such pronouncements. Shame.
Did your ears also tell you the PHC broadcast is digital by satellite? So you could hear that the program lacked 'something digital' while the whole broadcast was digital??
Wow! That beats ESP!
Jan
Thank you.
So why was subliminal advertising banned in some places, if we couldn't even know if it worked or not? Hehe.
I believe some differences in audio, may very well, likewise, be subliminal in nature.
John, have you any idea how illogical and unscientific that is?
You listened, made a lot of predictions about methodology of the recording and transmission.
You freely accept that you can "prove" none of it, but then say that you bet you are right! Which then proves how clever and skilled you are !
A detractor of your past achievements I am not, but you just seem able to open your mouth wide enough to easily insert an oversized boot whenever you make such pronouncements. Shame.
In the end only the results matter, and John's results speak for themselves.
Subliminal advertising DID work, that's why it was banned. Just because we may not be able to put our listening impressions into words, it doesn't mean that they aren't real. Besides, describing sound with words is at best a loose analogy anyway.
John, have you any idea how illogical and unscientific that is?
You listened, made a lot of predictions about methodology of the recording and transmission.
You freely accept that you can "prove" none of it, but then say that you bet you are right! Which then proves how clever and skilled you are !
A detractor of your past achievements I am not, but you just seem able to open your mouth wide enough to easily insert an oversized boot whenever you make such pronouncements. Shame.
Often, seasoned experts in various fields work by intuition, judgement, and feel. This is how some of the best work is done. Only at some later time may the work be extended in a more formal sense. For example, many theoretical physicists have worked this way at times, including Wheeler, Einstein, and Bohr.
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