Similar horrible truth about audio interconnect cables. I have known audiophiles who swear by the bible that a $200 Monster cable sounds "vastly superior" to a $5 no-name coax cable. I have done many measurements/tests including intermods and harmonic distortions, and could not see any difference whatsoever. While not an audiophile, I have very sensitive ears, yet cannot hear any difference.

Yet the same people are happy with Zoom audio recorders as soon as they came out, and use them as the audio capture for the camcorders. To my ears, the early models of Zoom (e.g. H2, H4) sounded horrible: noisy, high distortions.

My conclusion? The great majority of the audiophiles are those who have pretty average (or even bad) ears, but who are susceptible to misleading or sexy advertising.

And speaking of double blind tests, when Bloom posted his results, people couldn't tell one camera from another. And that was single blind.

May be it tells more about Bloom, compression and may be something about people? :-) I mean, it is not blind test fault.

Add to this that you constantly turn things thing into cameras :-) Problem is - vision and sound play different roles in our perception and they are differently processed and affected by our brain state.

I say this because if you are going to use the blind testing standard, there is no reason to upgrade video cams. Why have a double standard?

Because it is scientifically proven way to test audio.

"I think it is whole point to detail problems if you see them and have scientific and measurable proof."

Vitaliy, the reason "I don't have time to even begin to detail the mistakes" is that the science I have accumulated is not going to be appreciated by somebody who has not worked in audio design as a professional. I gave three examples of MAJOR parameters which were not canvassed in the blog, indeed are poorly understood these days "Intermodulation distortion," "Transient Intermodulation distortion," the ear's preference for even harmonics over odd". Measuring the IM shows class AB crossover distortion pretty clearly. Transient IM shows poor power conservation in many class AB op-amps (and discrete designs).

Sorry I don't have anything better than the PDF, the Internet didn't exist in 1979. Nor did scanners, or PDF files, for that matter. Much of this early knowledge has vanished into the bigger library collections. Maybe some day I will have the time to dig it out... And that was the point of my post. The old knowledge is dying out... Much has been forgotten over the decades since the NE5532 was designed... I did write up my experiences designing with today's Class D amplifiers, however, maybe somebody will work through its detail one day:

http://trevormarshall.com/class-d-tutorial/

I have a lot of gear that was designed so that you can just pop out the op amp and pop in another one. You can definitely hear the difference. I'm not saying one sounds better than the other, they just sound different. Some of them are clearer, some are warmer, some capture fast moving transients better. I think the whole "scientific" thing would be like choosing a video camera purely based on the DxO mark. Why would you do that?

I have definitely heard some NE 5534/5532 designs that sounded good, but I like the Grace discrete OpAmp the best, and I have LM, AD & THS in my preamps. The LMs may not be the best around, but I don't see any reason to upgrade. But if I want to upgrade, just order the part and pop it in the socket.

However, since my FR2LE (NJM 2122 OpAmps) and DR 680 sound fine with their stock opamps, I don't see a compelling need to replace them. There is always the issue of stability, or, even worse, RF in a mod. However, if I was to order a new high end converter, I would ask, as I always do, that the chips be socketed for easy upgrade. That way, any component part can be replaced without dumping the whole thing in a landfill and starting over. At a minimum, I can reuse my toroidal power supply and chassis, and usually I can keep the circuit board, pots and so on. Better for the environment.

Alternatives to resocketing: you can buy a state of the art preamp card for $125, and simply bypass whatever you have in your gear http://www.audioupgrades.com/products/products_pre_card.htm

Not going to fit in the the DR 680, but I have a dozen or so preamps with cards, and you can retrofit a whole console with these.

So if you like the way the stock opamps sound, don't change them, buy a better microphone. But they do sound different.

Tests: theoretically, a faster OpAmp should have lower crossover point distortion. However, most people don't even test that. I can't ever remember seeing a test for this, so what are they testing? But, again, what would it matter what the test is, if you prefer the sound?

I agree 100%. Since I do audio gear design on the side, I've always been interested in what makes gear "good" or "bad" according to the person who acquires it.

Chances are that the person has bought the hype surrounding certain gear, mostly around antique discrete gear. They focus on the discrete aspect but fail to take into account the whole design. Parts back then had much higher distortions and the decoupling was a lot worse, thus leading to a lot of different types of artifacts that people actually like to hear. Modern opamps were designed specifically to NOT have these artifacts and therefore don't have the "mojo" that the old parts do.

I used to frequent a DIY audio forum many years ago and the mis/disinformation became too much to bear, so I left. It became all about selling things to others and not trading good information anymore.

One of the worst was the opamp upgrade sale. So many people would come to the forum and want to upgrade their opamps simply because of so many others who heard magical transformations in their cheap crap gear after only changing a single part. A lot of people quickly jumped on the bandwagon and unless you were using certain opamps, there was no way your audio would sound good. Next came the folks doing the upgrades selling the same agenda to make money.

I did my own studies and found that I rather preferred the humble NE5532 and biploar electrolytic caps in my mixer rather than buying insanely expensive super-duper audiophile quality opamps and esoteric caps, and/or specialized things like DC servos and such.

Personally, I've always found the best way to upgrade cheap gear is usually to increase the local decoupling on the opamps and the bulk decoupling for the local opamp groups. Cheap gear tends to really lack in these areas. Most designs that use "cheap" opamps like the NE5532 also cheapen out on the power supplies and decoupling, so people who listen to these usually unfairly blame the active part instead of the supporting circuitry.

It is a pity that so much knowledge has disappeared over the past decade, as the Baby Boomers have retired, or passed away.

I don't have time to even begin to detail the mistakes in that blog, except to say that in the 1980's I designed a number of very high fidelity discrete component HiFi amplifiers - which did sound better than op-amps at the time. More importantly - they measured better as well. Cold hard parameters. Parameters missing in this blog.

See, for example http://trevormarshall.com/old_papers/Series-4000-Stereo-Amp-ETI.pdf Sadly, even I have lost the initial articles from that series, the articles showing Intermodulation performance.

"Intermodulation distortion," "Transient Intermodulation distortion," the ear's preference for even harmonics over odd, all these make a difference. Not a big difference, but a difference.

The mere fact that anybody can pretend to hear differences between amplifiers tells us that something is wrong. There should be no difference at all, yet there is indeed a lot of difference. Why? If any half-decent op-amp can do the job properly (as alleged in the above blog)?

Having said that, I currently use a switched power amplifier as my "reference standard" for audio, driving some amazing omnidirectional speakers through a mini-DSP for digital equalization and compensation. There are a heck of a lot of op-amps in that signal chain :) :)

http://trevormarshall.com/class-d-tutorial http://trevormarshall.com/ground-effect-omni/

There is nothing fundamentally wrong with the new technologies, but to close our eyes to the differences, rather than be aware of the limitation (and avoid them) is not the way to advance technology...