Immitation is The Sincerest Form Of Flattery.....
As to actual significance.....to some owners quite a lot, to the general hifi industry probably quite a lot also by introducing new techniques and understandings that invariably get emulated in one form or another.
To spend 40 years coming up with well regarded gear is a triumph in itself....this fact in itself says very much about John's ability to turn listening into designs that the audio world enjoys.
When the teacher speaks, the class ought to listen...
Dave.
And when a multitude are saying it, it's because of the common reason that that multitude can hear 'it'......measuring 'it' can be a whole different thing.
JC's designs have won awards because a good handful of people have judged them exactly by your criteria.
As to actual significance.....to some owners quite a lot, to the general hifi industry probably quite a lot also by introducing new techniques and understandings that invariably get emulated in one form or another.
To spend 40 years coming up with well regarded gear is a triumph in itself....this fact in itself says very much about John's ability to turn listening into designs that the audio world enjoys.
When the teacher speaks, the class ought to listen...
Dave.
Actually for me that's not "nuff said" in fact that's not anything said. The audiophiles who buy those tees for their wires and those vacuum tubes dipped in liquid nitrogen or sheep dip or whatever the magic juice of the moment is make the same claims. And they swear to it until they are blindfolded and then can't tell one from another. Small wonder this industry hates blind testing, nobody can stand up to it.
It has always struck me as odd that people who say they are engineers or physicists and produced what they claim are better products not only don't have facts to back those claims up, they've never had the intellectual curiousity to find out if it's true. 150 years ago, traveling medicine shows used to sell cures for everything from baldness to rheumatism with lots of testimonials to back those claims up and nothing else. That's why the FDA was created. IMO the high end audio industry is at about the same stage as the home remedy traveling medicine shows were in the mid to late 19th century. Testimonials, awards, rave reviews, and little or nothing else to distinguish it. How about a meaningful reply that actually explains it...or how about admitting that you just don't know how or why and can't prove it at all, that all you have is testimonials and awards from the industry that supports whatever it thinks will make it money?
Then how about some documented facts? How about more than accolades or awards. How about.....technical proof!?
Bose 901 has been on the market for over 40 years. The guy started a billion dollar a year private company with it but I don't think anyone here would throw flowers at his design. So what does longevity have to say about how well something works? Nothing. There is not necessarily any relationship between them. Now about those facts.....
Yes, it seems in a conventional blind testing that people can't tell the difference between CD and SACD, or high quality op amps. So, it's all over ... there is no point in discussing any circuit theory at all.
Well, I don't believe that. Even PMA says the OPA134 isn't good enough.
No one really knows what is audible or not. If it's measurable, it's open game in my opinion.
Ed Simon has shown that passive components produce measureable distortion, and given that distortion is additive, whose to say the passive components don't make an audible difference.
John
Money Talks...BS Walks....
Granted the Ultra High End is in silly territory....John Curl is about amplifiers and his products sell....and to realists.
JC does not make other than standard measurement claims for his designs...it is the market that judges his products to be sonically good.
Sure there are plenty of good other products, and by John's own admission at least one of his products has been panned.
We all wish we had measurement data that describes every last nuance in the behaviour of any piece of audio gear, but alas the standard distortion and noise, frequency response, noise, phase and fft are not quite sensitive enough ....so far.
Ears talk, and ears buy.
John, are you able to give a summary of the products that you have designed in the past 10 or 15 years, and your sonic evaluations of the final production versions that are available ?.
Thanks, Dave.
Granted the Ultra High End is in silly territory....John Curl is about amplifiers and his products sell....and to realists.
JC does not make other than standard measurement claims for his designs...it is the market that judges his products to be sonically good.
Sure there are plenty of good other products, and by John's own admission at least one of his products has been panned.
We all wish we had measurement data that describes every last nuance in the behaviour of any piece of audio gear, but alas the standard distortion and noise, frequency response, noise, phase and fft are not quite sensitive enough ....so far.
Ears talk, and ears buy.
John, are you able to give a summary of the products that you have designed in the past 10 or 15 years, and your sonic evaluations of the final production versions that are available ?.
Thanks, Dave.
Getting back to something potentially useful:
This is the life cycle of a Parasound product. This could also be said for Adcom, and several other competing designs over the decades.
In Parasound's case, marketing finds an 'opening' to fill out their sales line. Dealer feedback is important in this. Then a general description of the product, let us say, a power amplifier is drawn up. Let's say stereo 200W/ch top of the line (for Parasound) balanced or unbalanced in, capable of driving 4 ohm loads continuously, if necessary, without overheating.
Then the designer (me, in this case) puts forth a primitive schematic as to how to make this amp. This schematic is similar to what is presented on this website very often.
Now this is where the DESIGNERS separate the amp's characteristics.
Some designers believe that slew rate, x-over distortion, and higher order harmonics are VERY important. Others, equally capable, don't believe that x-over distortion is audible, and that a modest slew rate is OK.
Still others might go for high efficiency and make a class D amp, yet another might make a Class H amp, and so on, in order to lighten the heatsink demand.
Yet again, others might go for extremely low distortion specs, using very high feedback overall and 'nested loops' internally to get the lowest distortion measurable. etc. etc
In any case, each designer has 'his' beliefs in the design approach.
Then the amp prototype is made. Usually, experienced amp producers, based in Taiwan, and elsewhere, add 'boilerplate' features, such as: protection, auto turn on and off, etc. and a prototype is made, and sent to the 'designer'. The designer then tests the amp, hopefully listens to it, and sends recommendations for optimizing the design, and perhaps 100 get fabricated, tested and sent to dealers. For the next batch, any feedback that we get from dealers, reviewers, etc, will be put forth as engineering changes, and the next batch will be made, maybe 250 this time. And so it goes.
This is fine for a year or two, but then MARKETING gets an itch to make a new product. This time they might want 350W, for example. At the same time, they might also want to make a 100W product, at a SIGNIFICANTLY LOWER COST. Then the designer gets to work, scaling OR improving the initial design to make it happen, and the cycle begins again.
The most important part of this explanation is what happens to the original products? Well, they become 'obsolete', are not made any further, yet they are just as viable as when they were first designed. They are often remaindered out through mail order catalogues, at a discounted price. Such a bargain!
This is the life cycle of a Parasound product. This could also be said for Adcom, and several other competing designs over the decades.
In Parasound's case, marketing finds an 'opening' to fill out their sales line. Dealer feedback is important in this. Then a general description of the product, let us say, a power amplifier is drawn up. Let's say stereo 200W/ch top of the line (for Parasound) balanced or unbalanced in, capable of driving 4 ohm loads continuously, if necessary, without overheating.
Then the designer (me, in this case) puts forth a primitive schematic as to how to make this amp. This schematic is similar to what is presented on this website very often.
Now this is where the DESIGNERS separate the amp's characteristics.
Some designers believe that slew rate, x-over distortion, and higher order harmonics are VERY important. Others, equally capable, don't believe that x-over distortion is audible, and that a modest slew rate is OK.
Still others might go for high efficiency and make a class D amp, yet another might make a Class H amp, and so on, in order to lighten the heatsink demand.
Yet again, others might go for extremely low distortion specs, using very high feedback overall and 'nested loops' internally to get the lowest distortion measurable. etc. etc
In any case, each designer has 'his' beliefs in the design approach.
Then the amp prototype is made. Usually, experienced amp producers, based in Taiwan, and elsewhere, add 'boilerplate' features, such as: protection, auto turn on and off, etc. and a prototype is made, and sent to the 'designer'. The designer then tests the amp, hopefully listens to it, and sends recommendations for optimizing the design, and perhaps 100 get fabricated, tested and sent to dealers. For the next batch, any feedback that we get from dealers, reviewers, etc, will be put forth as engineering changes, and the next batch will be made, maybe 250 this time. And so it goes.
This is fine for a year or two, but then MARKETING gets an itch to make a new product. This time they might want 350W, for example. At the same time, they might also want to make a 100W product, at a SIGNIFICANTLY LOWER COST. Then the designer gets to work, scaling OR improving the initial design to make it happen, and the cycle begins again.
The most important part of this explanation is what happens to the original products? Well, they become 'obsolete', are not made any further, yet they are just as viable as when they were first designed. They are often remaindered out through mail order catalogues, at a discounted price. Such a bargain!
Last edited:
Dave this is not correct. Those measurements are fully up to the task. Show me a well-controlled test that delivers audible differences and I'll measure them for you.
jan didden
Dave, as the 'designers' lead separate lives, so do people contributing to this thread.
As I have maintained for 32 years, through DIRECT EXPERIENCE, double blind testing of the ABX kind will NOT separate most of the passive components. ONLY long term testing will do this, and while it is NOT NECESSARY to peek, it is certainly a lot easier than to make a PERFECT switch-box. For what do I care whether a Roederstein or a Dale resistor wins a listening comparison? They both cost about the same. I have no stock or personal interest in EITHER company, and NOW in fact they are the SAME company, but they were NOT even in the same country, 10 or more years ago, when I first made my choices.
As I have maintained for 32 years, through DIRECT EXPERIENCE, double blind testing of the ABX kind will NOT separate most of the passive components. ONLY long term testing will do this, and while it is NOT NECESSARY to peek, it is certainly a lot easier than to make a PERFECT switch-box. For what do I care whether a Roederstein or a Dale resistor wins a listening comparison? They both cost about the same. I have no stock or personal interest in EITHER company, and NOW in fact they are the SAME company, but they were NOT even in the same country, 10 or more years ago, when I first made my choices.
Last edited:
If you ask me it's really more like a numbers game when you get right down to it.
I mean, when you're not able to demonstrate actual audible differences, what do the engineers have left but numbers to bandy about?
It seems the spec wars of the 1970's never really left us. They just burrowed deeper is all.
se
As I said one of the dangers of just presenting data. There are very few resistors in any reasonable signal path and to say that the majority of them were operating at a large fraction of their power rating, I would say you have a pretty poor design. Remember signal grows algebraiclly in a signal chain while the resistor non-linearities grow as the square of the signal so only the end matters. Yes people have messed up and not realized that the feedback network in a 400W amplifier has LOTS of volts rms on it, so put a 5W Dale in there end of story.
Last edited:
For disco club use, i'll throw several bouquets of flowers.
It's just when i see them at some people's home, i can't help but giggle.
YouTube - Pulgoso - La Risa
A simple way to improve the sound is to dip the listener in sheepdip: Sheep Dip, Sheep Dip Whisky, Sheep Dip Whiskey
That makes the sound much smoother...
Wrinkle
Data is data, opinions are opinions! Poor design... on a diy site? There actually are some components that are bad enough by themselves they could distort the sound. The good news is I have never seen a competent design use them.
However Scott the generation of some resistor distortion does increase with the square of the voltage across them, but once the distortion is created it adds with other distortions according to the well understood phase relationships. (I do not want to involve even vector math so you are welcome to remind me of the problems in oversimplification.)
The actual issue that I think gets lost is how the "Fletcher Munson" curves affect distortion perception.
A 150hz tone at the evil 13th harmonic would pick up around 32 db of Flether-Munson relative "gain" in addition to the loss of masking due to the decline of musical energy by about 11 db. So if you allow for only -30 db in distortion detection that would require -73 for that distortion to pass unheard. If you consider the added gain of the ears filtering ability that would add another 10 or so.
So where it is possible to measure distortion quite accurately it is not as easy to determine under what conditions what level or type of distortion is actually perceived.
The other issue is actually using the equipment correctly. If I have a CD player with 2 volts RMS maximum output going into an amplifier with 26db of power gain into a 4 ohm loudspeaker with 103 db/W @ 1m output, there would be a peak sound pressure level of 123 db @ 2m listening position. Adequate for even a reasonable symphony. (Rock concerts like 102 db at 100 feet) With a leakage current of 30ua (Very Typical) using interconnects with 1 ohm of shield resistance (A bit high but in the range of what I have measured) then the hum would be 30 db for a dynamic range of 93 db or less than even a CD should have available. So even things that on the surface (like flipping around AC plugs) seem stupid can have an effect.
It is the denial or silly explanations of these kinds of issues that is great for creating heat without light.
ES
Huh?
The hum would be 30dB for a dynamic range of 93dB? In other words, you're saying that of the 123dB at 2 meters, 30dB of that is noise?
How exactly are you arriving at that figure?
se
30ua into 1 ohm = 30uv x 26 db gain = 600uv. 600uv into 4 ohms = .00000009 watts or -70 re 1 W.
Or try 30uv/2V = -96db. (I screwed up and forgot it's 6 db at 2 m not 3)
Last edited:
Once you'll realize that there are differences between measurements results and listening tests you'll make a huge step forward in audio gear assessment and production.
Well, it is people who find some products to be sonically better than others.
You want to see as market, rather than people, you may do so. However, the way you see it doesn't make it an actual fact.
Basically correct, but when I measure s/n there is no weighting unless so stated. 60hz at 30 db would not be heard at my listening position it would be heard with my ear next to the loudspeaker.
When you turn your question inside out, you begin to see why the 16 bits of a CD may not be enough resolution.
- Status
- Not open for further replies.