Those comments are old news to me. If you use high DF or high DA caps and you develop a voltage across them (as you would in an EQ or filter circuit) the distortion rises.
Now you guys can debate among yourselves if that level of distortion is audible to any one... Not my interest. My interest lays in what characteristic(s) could have an audible affect.... besides L, C and R. DA seems to correlate very well from what others say. DA is measurable and real... your only real argument is that it isnt audible in any case.
THx-RNMarsh
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Yes I also recall some material about the long-time-constant generation of potentials/tiny currents when teflon standoffs, etc., were mechanically stressed. I think again that it was alleged that it was a side effect of processing and that it had been alleviated.
I use tubing where I have to, when wires cross. The stuff is expensive, the bus wire now as well!
Pease was an advocate of air circuits for low leakage
MY apologies, you would have thought if you are going to the expense and effort of calibrating you would check it has done it right, I use the ColorMunki and check with my Cat... (and some RAL cards that I have photographed.)
When considering a new lens I use DXO Mark to check its measured performance as well as viewing sample photos, not that I buy lots of lenses, I am rather boring and only have three prime lenses a 24mm, 50mm and 100mm and saving up to finalise my collection with a Nikon 200mm f2 (my true love....). There is still a technical aspect to photography it is not all subjective... The finished photo is there to be viewed subjectively, but that is like a piece of music, it is art to be enjoyed in its own right, but you still want people to view it preferably as you intended (I do prints, I like a physical framed print over on screen) so again there are many aspects that can influence the finished piece, light used for viewing, paper etc. I use a Sony sensor in a Nikon Body and I love the colours and imager it is capable of, but even this sensor is not up to our eyes, but the Sony 36MP sensor is probably one of the best out there., and the first where subjectively to myself the final image matches that of good film.
There is still a lot of technical stuff involved in photography, both in taking the image, post processing the RAW data and printing...
Sunsets are a problem as are eclipses... I liked the colour in the second sunset, where is it.
https://www.flickr.com/photos/england78/16798906498/
I do mission life critical and very rarely use anything but FR4 based laminates, unless going above 4GHz and don't do many of them....
I will get new figures later this year for last years laminate use, as I said earlier the percentage of special laminates used is still very small, the figures are from the IPC world reports published every year.
AS to trying it, why, there will be no added benefit apart from increased manufacturing costs, just use a high glass content pre-preg with a fine weave, anything else is just fashion design, better to concentrate on good layout (again following good engineering practices not fashion layout).
In my days at Nokia many would often repeat that 'FR4 is only good for canoe making', but as many have said, if you specify the weave you want you get repeatable performance up to well over 2GHz. Get some no name boards from a cheap supplier in china and yes you will be having to add tuning pads all over the place, but given that even mixed signal boards rarely go above 4 layers I can't see a need for anything fancy except in the (limited) cases we all know about.
Yes
An Engineer's Aspect: Nikola Tesla - "Man's Greatest Achievement"
Yes but Michelson-Morley experiment(s) had to do only with investigating ether motion (relative velocity of ether to earth), not on proving or disproving ‘ether’ theory or the existense of ‘ether’
Michelson?Morley experiment - Wikipedia, the free encyclopedia
Here is a relevant Einstein's lecture from 1920:
Einstein: "Ether and Relativity"
George
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Still in production, sold the tooling to a small hybrid house IIRC. The raw performance has now been surpassed finally, what, some 50yr. almost later.
Thanks Richard for the input. I am up for almost anything, when the occasion allows.
We used 'teflon' boards in the CTC Blowtorch. They were expensive, and I will probably use something else for larger area circuit boards, but not just any FR-4. I had a couple of small problems with using 'teflon' but the problems were minor and nothing has come back from the board material or its potential weaknesses. We wanted to try the best materials that we could find at the time. I'm not sorry for the choice.
Perhaps SY should tell use what we should use, and then we would have a chance at throwing rocks at it, like he does with our choices. SE doesn't count. He doesn't make anything comparable.
We used 'teflon' boards in the CTC Blowtorch. They were expensive, and I will probably use something else for larger area circuit boards, but not just any FR-4. I had a couple of small problems with using 'teflon' but the problems were minor and nothing has come back from the board material or its potential weaknesses. We wanted to try the best materials that we could find at the time. I'm not sorry for the choice.
Perhaps SY should tell use what we should use, and then we would have a chance at throwing rocks at it, like he does with our choices. SE doesn't count. He doesn't make anything comparable.
More details please educate us.....
Of course being a layout engineer, I am always keeping up to date with laminates etc and what's going on in the PCB world, IPC is a great source here.
You do like putting down stuff though, do all the commercial boards in amps you use design use anything other than FR4...
I would like some proof that FR4 is bad for audio as said before it seems to do pretty well at everything else including professional audio, consumer audio....
Fashion me thinks, esoteric audiophile beliefs.
You can use what you want but don't dumb down perfectly adequate materials just to cater to the fashion section.
https://www.rogerscorp.com/document...n-To-Use-FR-4-Or-High-Frequency-Laminates.pdf
cameras --- 40MP and 1300 dpi seems the equiv of our eyes.
-RNM
cameras --- 40MP and 1300 dpi seems the equiv of our eyes.
-RNM
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Funnily enough, the "aether" has never been so present: the crude and simplistic version tested by M & M has been ruled out, but the relativistic "fabric of space-time" (which is allowed to stretch at superluminic velocities), the quantum fluctuations of vacuum, the dark matter and the dark energy are a kind of euphemism for something that looks like aether, tastes like aether, etc, but has some peculiar added (and carefully designed) properties.
Some advanced experiments even hint at isotropy for some particles, with the detection of seasonal variations linked to the orientation wrt to our galaxy.
We now realize that at least 95% of our known universe completely escapes explanations, theories and models. The true figure is probably even worse.
In fact, we are in an even worse position than when M & M made their landmark experiment.
What will finally emerge will be seriously different: the standard model and the relativity will have to go, that at least is a certitude, but none of the contenders look satisfying enough: MOND or SUSY may have promising aspects, but they are not able to fill all the gaps.
I just hope I live long enough to see at least some of the answers...
One of my favourite forums...
But from 2003, I can supply a lot of material that sais the opposite of what is on that thread....
Like this for instance...
What PCB material do I need to use for RF? | EDN
But here the relevance is Audio, and even if you include the digital side you are not getting into frequencies where FR4 will show problems.... Even if you add DDR memory and wireless communications.
Some nice RF board pictures, but again its a different world to audio in terms of frequency and layout.....
Ceramic pcb,Rogers pcb,RF pcb,Teflon pcb,RF Circuit - A-TECH CIRCUITS
FR4, perfect for your needs, but you wont listen to me for similar reasons to others, even though I am a professional in that field...
As I keep stating there are different brands of FR4, if you use bargain basement manufacture you are asking for trouble, how long ago were you at Nokia just out of interest....
In recent years rise times, clock speeds and the addition of RF comms on nearly every board as well as the extra thermal stresses lead free has meant that over the last 10-15 years PCB materials (mainly FR4) have evolved to cater for these new requirements.......
How relevant is multi GHz design to audio.....
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