To my experience, many times long listening period is much better at evaluating the sound quality of components for audio system than short term swapping of components. More than once I liked a component at first audition, to find out its' shortcomings after a longer period of listening, some times a week or more.
As I said previously, IF I tried to help an audiophile to improve an HCA3500 for example, people like Scott Wurcer would attack the very essence of my 'improvements'. Jan would require measurements, and SY would demand a double blind test. I might as well say this before anything is attempted. I am very serious in this statement, and I can back it up. This is why I often try to stay here on the 'straight and narrow' with design concepts that might bore PMA, but keep me out of trouble.
However, let me give you a 'proven' example of my modifications:
About 20 years ago, I designed my first power amp for Parasound. It was called the HCA-2200 MK 1. At the input was a dual fet input IC that ONLY allowed easy balanced to unbalanced input. I was elected to find the best IC for the job. I found the best IC that I could find, that met the specifications necessary. It had to be dual, minidip, unity gain compensated, and jfet input.
Measured good, however, independent reviewing of the product rejected the entire amp.
Now, if I were someone else, I would have 'blown off' the review, but being a little more experienced with certain problems, I decided to REMOVE the IC from the audio path. Guess what? It then got a 'B' review in 'Stereophile', and we were off and running. And that is the secret of my success!
However, let me give you a 'proven' example of my modifications:
About 20 years ago, I designed my first power amp for Parasound. It was called the HCA-2200 MK 1. At the input was a dual fet input IC that ONLY allowed easy balanced to unbalanced input. I was elected to find the best IC for the job. I found the best IC that I could find, that met the specifications necessary. It had to be dual, minidip, unity gain compensated, and jfet input.
Measured good, however, independent reviewing of the product rejected the entire amp.
Now, if I were someone else, I would have 'blown off' the review, but being a little more experienced with certain problems, I decided to REMOVE the IC from the audio path. Guess what? It then got a 'B' review in 'Stereophile', and we were off and running. And that is the secret of my success!
Well, I can't speak for Scott or SY, but I I would hope you would want to come up with some measurements or arguments to support your improvements. Some arguments we could could follow as to why the change would be an improvement.
I mean, if you would say: change this R to 10k because it sounds much better, naturally I at least would ask why. I would ask: does it increase the slew rate? From what to what? Or does it increase the PSRR, by how many db? Or maybe it increases input stage linearity, how so? That's a reasonable technical discussion, that's something we (or at least I) learn from, things we can use to improve our own designs. Isn't that what you have stated as your goal? To help people how to improve their designs?
So please don't make it look as if you don't want to bring up changes because you fear the questions. Surely you have a good arguments for those changes? Then tell us.
jan didden
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But what if you don't measure its existance in the first place? If a signal chain has no 13th harmonic of 150Hz or whatever what is the point in arguing its audibility?
It's not so long since people here asked you for the same regarding claims which you made at that time...........they remain, as far as I can see, awaiting!
Why not be more reasonable and grant JC the same privacy you so clearly expect for your own ideas.
Jan,
......but what if the improvement produced inferior specs but sounded much better...........sometimes you can't qualify and quantify sonic improvements. I say that sometimes meters don't tell you everything.........if they did tube amps might have cease to exist decades ago.
Your humble student,
Jam
......but what if the improvement produced inferior specs but sounded much better...........sometimes you can't qualify and quantify sonic improvements. I say that sometimes meters don't tell you everything.........if they did tube amps might have cease to exist decades ago.
Your humble student,
Jam
More interesting would have been to see what sort of review you would have got had you simply told them you'd removed the IC from the signal path.
se
Yes, I learned it from Siliconix in the late '60's. In the early 70's, I designed measurement microphone electronics with it. Later, it became more practical when cost effective DUAL matched jfets came in the same package. Then it became a real advantage to use it, because it could be direct coupled in and out, a real advantage, over my originally preferred design that I I used since 1970, that used a complementary self biasing jfet follower. The complementary design is actually better, but it always has an offset, that is difficult to remove.
My posts are falling behind, but I might pose an interesting scenario for some audiophiles. Let us say that you have a home playback system, composed entirely of vacuum tubes. Of course, that would be impossible for digital, but let's say you have a good vinyl record collection and truly enjoy it. Now, somewhere, at sometime, you found an electronic crossover with IC's in the high frequency thru-path, however it does virtually everything you could ask for in an electronic crossover. Do you think that you could detect a SINGLE IC/channel added in series with your all tube design, while playing an early Joan Baez recording? Let's ask, everyone. ;-)
Thought you said 103dB/W at 1M? And listening position is 2M.
But let's cut to the chase here.
If you can't hear it at the listening position, it's irrelevant. If you can, then you've got a rather poorly designed system.
se
30ua of leakage current is the threshold of degrading the 16 bits of a CD standard. Medical transformers allow 50 or 100ua. There actually are many amplifiers that have more leakage than that. You may also have more than a CD player connected straight to an amplifier.
The point is that there are issues that degrade the sound that are non-obvious. This causes some folks to blame what they do not understand on Poltergeists, and other very scientific explanations.
Hum out of a loudspeaker even with your ear at the cone is a reason to return a piece of equipment as defective.
Well that's no problem at all. Measured specs can be compared and repeated and are a relatively 'objective' measure of how clean and transparent an amp processes it's signal. 'Sounds much better' is a very personal and taste-dependent (and about 100 other factors) so really says nothing about the 'quality' of the amp.
Interesting, isn't it? I have posted several times here that there are many people that swear by tube amps, that they feel they sound 'best'. Others want only discrete open loop amps, others pay 5-figure amounts of money for ultra-high feedback Halcro's.
What does that tell you about 'better sounding'? That it's very personal, taste dependent and thus completely unreliable as a measure of 'sound quality'.
I don't think there's any meaningfull way to try to couple measurements to what people feel 'sounds better'. They are 'appreciation systems' if I may call it that, which are worlds apart.
jan didden
Then you apply the same method to the 11th, if no 11th try the 9th etc. Of course if you don't find any distortion then it is more likely your analyzer is broken
My opinion is that 16 bits is not enough to cover the normal (Whatever that is) human hearing range. I think it really takes 26 bits. Also I feel that some folks can hear 5 degrees of phase shift at 20khz as reported by R. Neve and M. Schroeder. I don't know of any audio gear that meets these design goals.
If you want to repeat Schroeder's experiment you can create .wav files that contain sine waves and harmonics. Be sure to keep the amplitude constant as you create files with different phase shifts. With a good monitor speaker you can see how much phase shift you can perceive.
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