Did anyone noticed what Bateman said about capacitors in his amp's Zobel network? There was some talk about the caps in that Parasound integrated several pages ago. To me they looked marginal, but what do I know..
Also, mountainman bob, did you spotted how many amps Bateman destroyed in the process?
Many amps - especially the D Self blameless type with the older 4-5 MHz fT OPS transistors - suffered from cross conduction at HF. I suspect that this was also a factor in Bateman's destruction of his test amps as well as OPS instability.
It seems EF2's can take quite a bit of abuse in terms of layout etc. I've had T03's mounted on a heatsink and run 150mm (6") wires to the devices from the PCB and the amp was stable. You will struggle to do that with an EF3. Bob Cordell covers this very well and I have never had an instability problem on any EF3 post my 2005/6 250W design (here: Ovation 250 Power Amplifier) where I took no precautions on the proto and had a lot of problems trying to tame it until I included base stoppers, rail decouplers etc and a decent Zobel.
25 Watts at 20kHz??
I suspect only Ed has tweeters that can handle that for more than a couple of seconds without going phut.
At higher frequencies the inductance comes into play and the impedance rises a bit so many tweeters could handle that. My big ones can handle that quite easily.
IMO it's important to realise that some people are as thick as you know what and not to waste your time trying to explain
It is to those who sell things. It's thicker the better for them.it is of no importance.
Like medicine, there is more to audio than just what the 'experts' believe. It would still be interesting if all we had to do is to meet some 'spec' or list of parameters, but time and again there is more to it.
So far as I can look back, Richard Heyser had a 'revelation' back in the 1950's when he was working with JPL with a unique amplifier that I think was designed for a moon landing.
He told me that he took it home, just for fun, and connected it to his K-horn. He found that it sounded better than anything else in his experience. Now, this amp was special, but not in a linear way, and he was surprised of course, but he trusted his ears, and found that it was the lack of 'global negative feedback' was the key. Now, did others independently listen to his 'amp' and find the same results? Yes, because he gave an AES presentation and preprint on his design. It was so successful that somebody actually independently started making and selling the design. He was somewhat annoyed that he got no royalty from the enterprise. And so it goes!
So far as I can look back, Richard Heyser had a 'revelation' back in the 1950's when he was working with JPL with a unique amplifier that I think was designed for a moon landing.
He told me that he took it home, just for fun, and connected it to his K-horn. He found that it sounded better than anything else in his experience. Now, this amp was special, but not in a linear way, and he was surprised of course, but he trusted his ears, and found that it was the lack of 'global negative feedback' was the key. Now, did others independently listen to his 'amp' and find the same results? Yes, because he gave an AES presentation and preprint on his design. It was so successful that somebody actually independently started making and selling the design. He was somewhat annoyed that he got no royalty from the enterprise. And so it goes!
In my book, you are the classical example of 'experts'.
Those who have revelations should seek medical help.
Knowledge is not revealed, it must be worked for.
Oh, yes, in the 50s there was a strong NASA program for moon landings.
The amplifier was badly needed for the the follow-me car on the moon.
Oh, wait, Sputnik was in October 1957.
And after that, JPL was quite busy to build a beep-beep to catch up
to the Russians in 1958. Did they really have such a long-range pre-planning?
Oh, Kennedy's speech wrt the moon was in September 1962.
You can fool some people sometimes, but you cannot fool all the people all the time.
You have used up your budget of "some" since a long time, and then some more.
That's insulting for anyone with at least half a brain.
No go back again to the ignore list.
Disgusting.
Gerhard
For audio perhaps. What about audio reproduction in which the performance is determined by its accuracy to the sound source?
You mean the Apollo Program started in the 50's?
Probably the following...
Attachments
You freely distort the devil's advocate aspect of Mr. Heyser and Feynman because they are no longer with us to suit whatever point you want to make. They would both laugh at things like BQP's like they were some kind of stupid joke if they were still with us.
In Depth | Ranger 1 – NASA Solar System Exploration
Launch Date Aug. 23, 1961
Was it designed and built overnight? Most probably not, so this project might have started in the late 50's, like in 1959.
Anyone from JPL or NASA here?
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Hopefully, I can post his original pre-print so it was apparently after Sputnik that he did this work. He told me about it about 10 years later, by then it was old stuff to him. However, I thank my luck in not only knowing him, but being open minded enough that he opened up to me about what he had found important in audio design. Remember, this was just before Otala and TIM, that he talked to me about feedback.
Now, I use global feedback in almost every design that I make. I have a very large amp on my bench right now, and it has significant global feedback. Of course not as much as an IC op amp might use, but a lot, anyway.
BUT, in experience, designing a circuit so linear that it does not need global negative feedback has always been my best sounding, like the CTC Blowtorch and the input gain block of the Vendetta Research SCP-2. These are 'legendary' designs, and not because I say so.
Of course, Charley Hansen took it even further to power amps. I just can't go that far and make a commercial product, but Charley was still right about it.
Now, if you wise guys would get off your duffs and find out WHY global feedback usually compromises circuits, instead of just attacking me, maybe we could make some progress.
I deeply resent Scott Wurcer implying that I am a liar, or even an exaggerator of what Richard Heyser told me, about 50 years ago. I am stating what I was told. Of course, then I listened, and when Matti Otala published about TIM, I tried my hand at low feedback, high open loop bandwidth (also an Otala requirement) designs. This got me in good with GD, and the Wall of Sound electronics, Mark Levinson with the JC-2 and the ML-2 power amp (try to buy one of these today). In fact, it made me famous, so listen up everybody, keep an open mind. There is more coming down the line with FM distortion for example, that adds to the picture, and therefore more progress in making better audio electronics.
Now, I use global feedback in almost every design that I make. I have a very large amp on my bench right now, and it has significant global feedback. Of course not as much as an IC op amp might use, but a lot, anyway.
BUT, in experience, designing a circuit so linear that it does not need global negative feedback has always been my best sounding, like the CTC Blowtorch and the input gain block of the Vendetta Research SCP-2. These are 'legendary' designs, and not because I say so.
Of course, Charley Hansen took it even further to power amps. I just can't go that far and make a commercial product, but Charley was still right about it.
Now, if you wise guys would get off your duffs and find out WHY global feedback usually compromises circuits, instead of just attacking me, maybe we could make some progress.
I deeply resent Scott Wurcer implying that I am a liar, or even an exaggerator of what Richard Heyser told me, about 50 years ago. I am stating what I was told. Of course, then I listened, and when Matti Otala published about TIM, I tried my hand at low feedback, high open loop bandwidth (also an Otala requirement) designs. This got me in good with GD, and the Wall of Sound electronics, Mark Levinson with the JC-2 and the ML-2 power amp (try to buy one of these today). In fact, it made me famous, so listen up everybody, keep an open mind. There is more coming down the line with FM distortion for example, that adds to the picture, and therefore more progress in making better audio electronics.
Project Vanguard was "on schedule" (for however good such schedules are) to launch a satellite in the 1957-1958 timeframe.
Vanguard (rocket - Wikipedia)
I did neither, Mr. Heyser played the devil's advocate in many of his writings, he entertained some ambiguity and wanted folks to think. If you think this meant he would take something like BQP's seriously you are mistaken.
I am sure Heyser most certainly would give large BQP a listen, Feynman too probably and from what I understand of Heyser he would not be laughing, I reckon he would be intrigued and his curiosity piqued.
It is notable that the origins and mechanisms of 1/f noise are still not understood and explained despite long investigation.
There are still plenty of mysteries in this world, the full story of energy transmission, transduction and 'handover' is not yet explained, large BQP is demonstrating that quantum noise/current noise can be 'controlled' and 'defined', my experiments are demonstrating this also.
This 'noise control' is happening already albeit randomly throughout electronic and electrical systems and according to the materials employed, what is 'novel' is installing a system or circuit lumped element (BQP or Goop) that advantageously and predictably strongly defines conduction noise and consequent upstream and downstream system behaviours.
BQP is an electrically in series element, Goop is a parallel or dielectric circuit element and both alter system noise behaviours same as every other conductor or insulator/dielectric does, the difference is that certain compounds in combination/mixed have strong and overriding 'filtering' effect, but not filtering in the way that we commonly implement in the form of RLC stages....this is the stumbling block that confounds those not personally familiar with devices such as large BQP (and Goop).
The likes of pre Inca and other ancient megalithic structures are not understood......just how did the ancients quarry, transport and fit giant stones together with such precision ?.
The ancients did have so called geopolymer (concrete/mortar like material) but that does not explain all, plenty of South American stoneworks look as if the stones were molded into place using some kind of liquefaction process, it is seemingly impossible according to our current knowledge to mark, finesse and final fit 10 ton, 20 ton and much greater weight chunks of rock with the sub mm precision routinely exhibited in these relics of prehistory.
It seems the ancients knew how to routinely openly manipulate energies and matter in ways that we do not, I say it is folly to so vigorously denounce the likes of large BQP, or for example to so vigorously denounce the possibility of long term effects of EMR on the behaviours of biological systems when we are still at such infant stage in man made electrical technology.
IOW nobody here is 'expert' in the questions of the universe, we have learned to manipulate energies in various ways but we still have no real idea of what energy really is and no real idea of what matter really is.
Scott, you have designed some significant/famous devices same as JC has designed significant/famous audio electronics, but when it comes down to it all of us are clueless as to what really goes on, we see the surface concepts but not the final details.......some terms of Maxwell are ignored in order to whittle down the unwiedy original set of 20 equations, large BQP and Goop answers must be in those disregarded terms.
Laurie Anderson - Ramon
"So when you see a man who's broken
Pick him up and carry him
And when you see a woman who's broken
Put her all into your arms
'Cause we don't know where we come from
We don't know what we are
And you?
You're no one
And you?
You're falling
And you?
You're traveling
Traveling at the speed of light"
The Dream Before
"She said, What is history?
And he said, History is an angel
Being blown
Backwards
Into the future
He said: History is a pile of debris
And the angel wants to go back and fix things
To repair the things that have been broken
But there is a storm blowing from Paradise
And the storm keeps blowing the angel
Backwards
Into the future"
Recommended listening is LA's Strange Angels album, lyrics to the songs are here, insightful, witty and thought provoking.
Egos and selfish behaviours abound around here same as any other field of human endeavor, it is sad that so many do not understand the concept of and power of humility when used for the common good.
Do we fade to black, or do we give final account to a higher force, none of us know for sure, some believe they are superior, there is no such thing.
Dan.
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