Joe, as you well know by now, these 'critics' have nothing good to say to you, or even useful to the reading followers. Just keep at your interest and report in when possible.
The way new ideas are put forward is by TRYING. Not hearing from the 'It's impossible' people.
For example: In 1966 I came by an article in the IEE (British) 'Letters' that first described to me what the REAL noise tradeoffs were in bipolar transistors. It showed that is was 'possible' to have very low input noise, BUT I had to find bipolar transistors with LOW Rbb' and this was not a typical spec on the data sheet.
So, in 1967, I visited Ortofon in Denmark, to ask a few technical questions about their MC cartridge, so that I 'might' be able to design a transformer replacement in solid state. The gentleman who talked to me said that their engineers had deemed it "impossible" and actually guided me to the door, as if I was some sort of nut.
Then later that year, I went to work at Ampex, and I was instructed to use a QuanTech noise analyzer to measure the noise of several transistors that we had available. It was a 'helper's' job, but I liked doing it, and I started measuring everything that came in, hoping that something special (that was really useful for ultra low noise) might pop up, and it did in 1968. It was the 2N4405, that was EXTREMELY QUIET (low Rbb'), but it only came in PNP, but the next choice was the 2N4403-2N4401 complementary pair. I could achieve 10 ohm equivalent noise with four 2N4405's in parallel, or Eight 2N4401's and 2n4403's in parallel. So I had solved the problem in 1968, but nowhere to implement a useful circuit.
Finally, 5 years later, Mark Levinson asked me to make a phono pre-preamp design. It was called the Levinson JC-1 pre-preamp and it used four 2N4401, and four 2N4403 in push pull parallel (my patented invention) and we took it to the NY AES convention in 1973, advertising its low noise. The feedback we got from some people at the AES was: "This is impossible without a transformer buried secretly inside the box". Of course it wasn't, and it took a few years for everybody else (including Ortofon) to catch on, but now it is commonplace in circuit design today. That's how things progress. NOT peer reviewed papers. '-)
The way new ideas are put forward is by TRYING. Not hearing from the 'It's impossible' people.
For example: In 1966 I came by an article in the IEE (British) 'Letters' that first described to me what the REAL noise tradeoffs were in bipolar transistors. It showed that is was 'possible' to have very low input noise, BUT I had to find bipolar transistors with LOW Rbb' and this was not a typical spec on the data sheet.
So, in 1967, I visited Ortofon in Denmark, to ask a few technical questions about their MC cartridge, so that I 'might' be able to design a transformer replacement in solid state. The gentleman who talked to me said that their engineers had deemed it "impossible" and actually guided me to the door, as if I was some sort of nut.
Then later that year, I went to work at Ampex, and I was instructed to use a QuanTech noise analyzer to measure the noise of several transistors that we had available. It was a 'helper's' job, but I liked doing it, and I started measuring everything that came in, hoping that something special (that was really useful for ultra low noise) might pop up, and it did in 1968. It was the 2N4405, that was EXTREMELY QUIET (low Rbb'), but it only came in PNP, but the next choice was the 2N4403-2N4401 complementary pair. I could achieve 10 ohm equivalent noise with four 2N4405's in parallel, or Eight 2N4401's and 2n4403's in parallel. So I had solved the problem in 1968, but nowhere to implement a useful circuit.
Finally, 5 years later, Mark Levinson asked me to make a phono pre-preamp design. It was called the Levinson JC-1 pre-preamp and it used four 2N4401, and four 2N4403 in push pull parallel (my patented invention) and we took it to the NY AES convention in 1973, advertising its low noise. The feedback we got from some people at the AES was: "This is impossible without a transformer buried secretly inside the box". Of course it wasn't, and it took a few years for everybody else (including Ortofon) to catch on, but now it is commonplace in circuit design today. That's how things progress. NOT peer reviewed papers. '-)
Last edited:
On another front, I just returned from the LA Audio Society's Awards meeting where I met with my fellow audio designers. I don't think any of them contribute here, unfortunately. It is nice to meet people that appreciate quality audio design.
John, can you do us a favor and actually summarize what Joe wants to accomplish? Because all it seems you enjoy doing on this thread is blindly encouraging anyone who antagonizes a few individuals that you've conflicted with previously (and simultaneously insult those same individuals for not having your "be so open minded to obvious malarky" mindset). For someone who likes to self-brand as a famous audio designer, I'd think you'd be more judicious in your support rather than, oh I don't know, using people as pawns to your desired pettiness.
Hey John,
All due respect, but I'm going to bet that your discovery was well known at Bell labs and instrument makers by the time you came along. I do think that what you successfully did was to introduce this technique to the audio world. The labs I'm talking about have huge budgets, the best test gear and the brightest, most imaginative minds in the sciences. They wouldn't waste their time and energy on what amounts to a hobby. Audio is a hobby to both the users and designers participating in the "industry".
For sure, applications engineers and staff scientists at the semiconductor companies working with the big labs were also well aware of this too. Just the radio telescope experiments demanded the quietest circuitry and semiconductors, then they cooled the entire shebang down with liquid Nitrogen. They had to in order to have any results not buried in noise. I'd love to see how they do this these days. You should find out and introduce / invent those ideas to the audio world.
-Chris
All due respect, but I'm going to bet that your discovery was well known at Bell labs and instrument makers by the time you came along. I do think that what you successfully did was to introduce this technique to the audio world. The labs I'm talking about have huge budgets, the best test gear and the brightest, most imaginative minds in the sciences. They wouldn't waste their time and energy on what amounts to a hobby. Audio is a hobby to both the users and designers participating in the "industry".
For sure, applications engineers and staff scientists at the semiconductor companies working with the big labs were also well aware of this too. Just the radio telescope experiments demanded the quietest circuitry and semiconductors, then they cooled the entire shebang down with liquid Nitrogen. They had to in order to have any results not buried in noise. I'd love to see how they do this these days. You should find out and introduce / invent those ideas to the audio world.
-Chris
Agreed. The big boys are years to decades ahead of what is considered state of the art in audio.
Even my little dvc thingy is six years old for me.
Some of the other stuff is a decade or two beyond.
The real problem is, until it crosses into consumer technology, it's a solution looking for a problem.
Jn
Even my little dvc thingy is six years old for me.
Some of the other stuff is a decade or two beyond.
The real problem is, until it crosses into consumer technology, it's a solution looking for a problem.
Jn
But John, Ortofon -- to this day -- thinks transformers are better than your (or anyone else's) head amp. https://www.ortofon.com/media/148351/20160411-ortofonmctransformersbrochure02_web.pdf
You can't limit peer review to yes men. From what I've seen in your writings here, they are not doing you a favor.
Encouraging someone is great, but that is not enough.
You confuse technical discussion with personal criticism. Many here are pointing out your technical misunderstanding, you either divert, attack, or play the martyr. It doesn't work for JC, why do you think it would work for you?
I've stated in the past...many here are quite good technically, you would be better served listening to them.
Unless of course your plan is to play martyr to garnish audience and sympathy.
Jn
Last edited:
Wow, such a technical retort.
But I understand you, you can't appear to be years or decades behind the best talent on the planet, what would your customers think??
After all, you claim you did something what, 50 years ago. Well, color me impressed.
I will admit, google has been getting better and better at finding contributions you've made to audio, with time, they keep going back in time scanning old articles.
Jn
Last edited:
Of course, I do, As I prefer to use as minimal ways as possible, my medium/treble speakers works close to their resonance frequencies.
Here some tips
For RLC (resonance compensation), the tool available here will save your calculations time:
La correction d impédance RLC série
And for RC:
La correction d impédance RC série
Note: As speakers are not purely inductive, you need often to add a second little C or RC in // with the resistance, if you want to linéarise impedance of tweeters up to 40KHz and more.
In this web site, you will find a database with the Thiele and Small values of lot of speakers all along with their compensation networks. And tools to calculate various enclosures as well: A must have. And the best: it is in the "langue de Molière" ;-)
Usually, the goal is to get a flat impedance equal to the DC resistance of the speaker, usually around 6 Ohms for a 8 Ohm speaker.
For a closed enclosure, you need to make your curve of impedance measurement once your speaker is in the box with his dumping material. For a bass reflex correctly designed (both peaks at the same level) you can make your measurements in free air, and adjust just the value of the resistance once in the box.
if you use active filtering, with high damping factor amplifiers, As I don't expect a lot of improvements, of course, I never tried compensation networks. But with passive filters and their serial impedance, even with BIG wires in the filters inductances you can see the benefit on your responses curves: it is obvious, and, as I said save time as the values of your filters components can be calculated with no further adjustments on the bench.
About inductances in your RLC compensation network, as there is a resistance in serial, you can use cheap little ones and subtract their resistance value from the value of the serial resistance itself.
My two cents.
Hi Simon, how are-you ? Thanks for your kind words. No I'm not back, or let's say I return now in my hot black hole, lurking from time to time to the light rays that comes from this forum during its endless rotation on himself ;-)
Not to ignore that I rotate on myself as well, but who cares from a black hole that nobody can see. ;-)
Last edited:
Well John, it was new to the audio world, so in that context I guess you invented it.
I don't think anything can be invented by folks who aren't working in the top tier labs (with credentials to match) in their garage or industrial unit. It would be very nice to think I could pull off that kind of feat, but it just isn't a reasonable expectation. I have often wondered, as I work through a design problem, how many times the solution has been developed before. There is no way that I'm going to come up with anything of value that hasn't already been explored. I hate to say it John, that applies to almost everyone here including you. No offense intended or implied. Just look at the dollars flowing into research labs and university labs. And what backing did you have to leap ahead of this military-industrial machine?
Maybe today's next audio genius will instead examine patents and industrial products to introduce to the audio community. No point in re-inventing the wheel, especially if real science has abandoned an approach and moved on to something better.
-Chris
I don't think anything can be invented by folks who aren't working in the top tier labs (with credentials to match) in their garage or industrial unit. It would be very nice to think I could pull off that kind of feat, but it just isn't a reasonable expectation. I have often wondered, as I work through a design problem, how many times the solution has been developed before. There is no way that I'm going to come up with anything of value that hasn't already been explored. I hate to say it John, that applies to almost everyone here including you. No offense intended or implied. Just look at the dollars flowing into research labs and university labs. And what backing did you have to leap ahead of this military-industrial machine?
Maybe today's next audio genius will instead examine patents and industrial products to introduce to the audio community. No point in re-inventing the wheel, especially if real science has abandoned an approach and moved on to something better.
-Chris
Gor3, unfortunately, you have been suckered by Ortofon marketing. Perhaps TODAY, they prefer a transformer. It might be their best solution, for them, as the best active devices are not available for general production anymore. But this did not stop Ortofon from copying my patented Levinson JC-1 circuit, with a simplified version that Mark had offered them to license to them for a modest royalty in 1973. By 1978, THEY claimed to have INVENTED the circuit. See how things work? When I threatened to sue, they 'laughed' at me. Then, in 1989, when I was making the Vendetta Research input stage, they tried to get me to sell them one, but I declined, explaining the previous copying of my earlier circuit. (Both designs had the same input noise). And so it goes!
I worked at AMPEX, Anatech in 1968. They had a big enough lab to get things done in. NOT MY GARAGE! I also made my first complementary differential input power amp in 1968. So there!
In my work, typically a problem needs to be solved, and nobody else has done it or tried. We consult around the world, talking to the best. Sometimes it bears fruit, sometimes you have to forge on alone.
Jn
Jn
Hi John,
Sorry, I didn't intend to suggest you did this in your garage. I'm well aware that you worked at Ampex during that time.
Still, to compare the labs at Ampex to those at Bell and semiconductor companies is a bit of a joke. Sure, they had more and better than most universities I bet, but they could not come up with any good argument to run a lab the size of those others. I'll bet there are massive labs that we don't even know exist.
One question comes to mind. Since you were employed at Ampex, and you did use their equipment and lab time to invent this. Don't they own the rights to that invention of yours? It seems directly applicable to their core business, and probably you failed to disclose your invention per the terms of most employment contracts. When I worked at the cal lab, any invention I came up with during that time frame would belong to Transcat. Good thing I didn't have any insights during that time.
You might have dodged a bullet there for years John.
-Chris
Sorry, I didn't intend to suggest you did this in your garage. I'm well aware that you worked at Ampex during that time.
Still, to compare the labs at Ampex to those at Bell and semiconductor companies is a bit of a joke. Sure, they had more and better than most universities I bet, but they could not come up with any good argument to run a lab the size of those others. I'll bet there are massive labs that we don't even know exist.
One question comes to mind. Since you were employed at Ampex, and you did use their equipment and lab time to invent this. Don't they own the rights to that invention of yours? It seems directly applicable to their core business, and probably you failed to disclose your invention per the terms of most employment contracts. When I worked at the cal lab, any invention I came up with during that time frame would belong to Transcat. Good thing I didn't have any insights during that time.
You might have dodged a bullet there for years John.
-Chris
Sure. That's a very different line of work. Not much relation to most audio design. We could use much better dacs for very low cost, though...
hmmm. Big assumptions. It may be that low Rbb was known for low noise by semiconductor physicists but it wasnt applied to audio apps. A new circuit using lowest Rbb transistors is a new invention IMO.
Then where would my invention of the DC servo for eliminating coupling caps/drift come in. Was it already invented because servo concept had been used in motor controls? I think that is also a stretch. Or that the unique characteristic of CFB in amps was already invented/known because feedback to a cathode had been used? Another stretch of the imagination. Or, two new filter topologies with practical app must have been known already because other filters have existed prior? Come on. Really?
It was the process of discovery that JC was describing, also. Step by small step until you get to a significant new point. Usually based upon a problem to be solved. Which is not unlike JNuetron's world, either.
THx-RNMarsh
Then where would my invention of the DC servo for eliminating coupling caps/drift come in. Was it already invented because servo concept had been used in motor controls? I think that is also a stretch. Or that the unique characteristic of CFB in amps was already invented/known because feedback to a cathode had been used? Another stretch of the imagination. Or, two new filter topologies with practical app must have been known already because other filters have existed prior? Come on. Really?
It was the process of discovery that JC was describing, also. Step by small step until you get to a significant new point. Usually based upon a problem to be solved. Which is not unlike JNuetron's world, either.
THx-RNMarsh
Last edited:
Hi Richard,
Yes, I know and accept that. I'm still doubtful that Ampex couldn't use that design as John created it. Any lab needing to amplify weak signals would need low noise, and a DC servo to keep that amplifier from drifting into clipping.
I think that John might have discovered prior art if he didn't know about it, and was the first to apply it to audio. However, I am also somewhat interested about the fact that John's development was not known to his employer and that this work was exactly what he was supposed to do for Ampex at the time. They could have bumped Studer off the top machine rank and had a different future had they been able to access John's development.
-Chris
Yes, I know and accept that. I'm still doubtful that Ampex couldn't use that design as John created it. Any lab needing to amplify weak signals would need low noise, and a DC servo to keep that amplifier from drifting into clipping.
I think that John might have discovered prior art if he didn't know about it, and was the first to apply it to audio. However, I am also somewhat interested about the fact that John's development was not known to his employer and that this work was exactly what he was supposed to do for Ampex at the time. They could have bumped Studer off the top machine rank and had a different future had they been able to access John's development.
-Chris
- Status
- Not open for further replies.