90 degree corners, have been debated with the same vigour in PCB design for many years. As to jagged traces, admittadly not done with sharp angles, have a look at some mother boards, where length matching is employed.
http://www.ultracad.com/articles/90deg.pdf
http://www.montrosecompliance.com/Technical_papers/corners-Japan.pdf
Electrons flying of corners, a more houmorus debate
OF FLYING ELECTRONS
http://www.ultracad.com/articles/90deg.pdf
http://www.montrosecompliance.com/Technical_papers/corners-Japan.pdf
Electrons flying of corners, a more houmorus debate
OF FLYING ELECTRONS
Just an example that many of the EE's are mindless twits, still view flow of electric charge as a rolller coaster ride, despite having been taught that it's not.
Unable to step outside their dogmatic state of mind, unable to see the paradox, unable to look elsewhere for a different perspective.
(sorry about that, time of the year outburst, back to my usual agnostic self)
Unable to step outside their dogmatic state of mind, unable to see the paradox, unable to look elsewhere for a different perspective.
(sorry about that, time of the year outburst, back to my usual agnostic self)
Gerhard, do you consider putting capacitor in series to the feedback resistor (mentioned 40 ohm) to control output DC offset and to cut-off subsonic garbage?
I’m trying to figure what would be advantage of having matched impedance in + and – arms of the input stage. Keep in mind that the cartridge impedance is complex and frequency dependent (also model dependent) so trying to match it seems pretty futile.
Then, if the goal is to minimize noise, choosing low values for feedback resistors has to be balanced with the output driving capability of the opamp. Mentioned 40E, 4K seems reasonable.
Chip
Don't know really. Building a preamp for a particular cartridge doesn't appeal to me so much. But in subsequent stages, matching the impedances is very audibly beneficial, at least to my ears. Nor reason the first stage should be any different.
As J.C. points out cartridge loading is quite important. So even a high impedance cartridge at 47k and 200 or so pf termination the R part is significant but not overwhelming. On a moving coil cartridge where the load is 1000 ohms or less 200pf drops to that value just under a megahertz! So a simple resistor is not so bad a dance partner.
The lower the feedback source impedance the lower the noise, but the greater the load on the voltage source. Then there are other considerations such as thermal drift. So there is a bit of work to pick values that are optimum!
Of course J.C. is still talking about old stuff and just what he has done. Just because he used to come up with creative ideas and was a winner in the past doesn't mean he will today, but that is the way to bet!
I used to have a fellow here who didn't think he needed to know all the old stuff, those were solved problems, he only wanted to do new stuff. I mentioned this to some of his professors, they changed the course requirements so no one else would ever come out as ignorant. The usual phrase is "The reason we can see so far today is that we stand on the shoulders of giants."
By the way J.C. Merry Christmas (I'll wait until next year to puncture your ego. After all it is almost as big as mine!)
ES
Without you this thread would go nowhere useful. Wait till Pavel gets his Christmas coal and warms up a bit, his humor will improve.
(I suspect that reference may not culturally translate very well.)
90 degree corners, have been debated with the same vigour in PCB design for many years. As to jagged traces, admittadly not done with sharp angles, have a look at some mother boards, where length matching is employed.
http://www.ultracad.com/articles/90deg.pdf
http://www.montrosecompliance.com/Technical_papers/corners-Japan.pdf
Electrons flying of corners, a more houmorus debate
OF FLYING ELECTRONS
"The very powerful and the very stupid have one thing in common. Instead of altering their views to fit the facts, they alter the facts to fit their views...which can be very uncomfortable if you happen to be one of the facts that needs altering." -- Dr. Who
By ear. I can't hear it.
But then I can't hear the differance
between a toroid and E core in the
power supply of a power-amp
(which he can) .....
the "shoulders of giants" quote fits with Mr Curl's online persona much better than many may suspect:
Wikinomics – The “truth” about Isaac Newton
Wikinomics – The “truth” about Isaac Newton
How do the ears fabricate the garbage physics? A little reading up on conduction in metals would help.
Yes, it is better that I don't try to teach anyone here about phono stage design in particular. I was getting dangerously close to showing what what just released this month, to consumers. It has already passed through the reviewing process, and that will be available, sometime in future. It is not a very 'innovative' design, just one that works.
Still, it is better to not talk about it, for the usual reasons often stated here.
There are many ways to approach phono design, and there are plenty of phono stages out there, to chose. I would be surprised if someone hasn't already taken SY's excellent design and put it into production, somewhere. That's what happens if you show it all, so to speak. Of course, they will take credit for it, and so it goes.
Many years ago, about 28, I think, I was at a CES where the first SOTA turntable was introduced, and my SOTA headamp was being displayed with it.
Literature put out at the show, showed where the SOTA turntable had trounced the LINN, and how wonderful it sounded, compared to everything else.
The problem is: The SOTA was prototyped in MY office, and I KNEW that it had NEVER been listened to, because it still didn't rotate! But the literature said just the opposite. You never know, unless you were there, I guess, about ANY advertising.
Well, I casually mentioned this to the writer of the literature in question and he called me every name in the book, in including: alcoholic, drug addict, and 'has been'. We were both dressed in business suits, in a public hallway. He said that MY best days were over, as I was approaching 40 years old, and he knew this from experience, since he had worked at Lawrence Berkeley Labs as a technician for the past 2 decades. AND even if the SOTA headamp had come from my previous patented idea, no more useful ideas would be forthcoming from me, in future. Well, I want to thank him for that!
Two weeks later, the inspiration for a new phono head amp came to mind, and Vendetta Research was born. Fueled by the put-down at CES, I made a breakthrough and never looked back.
Still, it is better to not talk about it, for the usual reasons often stated here.
There are many ways to approach phono design, and there are plenty of phono stages out there, to chose. I would be surprised if someone hasn't already taken SY's excellent design and put it into production, somewhere. That's what happens if you show it all, so to speak. Of course, they will take credit for it, and so it goes.
Many years ago, about 28, I think, I was at a CES where the first SOTA turntable was introduced, and my SOTA headamp was being displayed with it.
Literature put out at the show, showed where the SOTA turntable had trounced the LINN, and how wonderful it sounded, compared to everything else.
The problem is: The SOTA was prototyped in MY office, and I KNEW that it had NEVER been listened to, because it still didn't rotate! But the literature said just the opposite. You never know, unless you were there, I guess, about ANY advertising.
Well, I casually mentioned this to the writer of the literature in question and he called me every name in the book, in including: alcoholic, drug addict, and 'has been'. We were both dressed in business suits, in a public hallway. He said that MY best days were over, as I was approaching 40 years old, and he knew this from experience, since he had worked at Lawrence Berkeley Labs as a technician for the past 2 decades. AND even if the SOTA headamp had come from my previous patented idea, no more useful ideas would be forthcoming from me, in future. Well, I want to thank him for that!
Two weeks later, the inspiration for a new phono head amp came to mind, and Vendetta Research was born. Fueled by the put-down at CES, I made a breakthrough and never looked back.
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