To me what you are saying is that used measurements today cannot explain the sonic differences between some resistors. OK, I agree on that. Heck, 100 years ago we could not measure either X or Y or Z but today we can measure say X, Y, and Z.
Do strings in string theory exit? We cannot measure them...
Does the electron exist? We cannot (as far as I know) see one...
But we can do experiments with electrons ( = blind testing) that proove there is an electron there.
Sigurd
Do strings in string theory exit? We cannot measure them...
Does the electron exist? We cannot (as far as I know) see one...
But we can do experiments with electrons ( = blind testing) that proove there is an electron there.
Sigurd
scott wurcer said:
Sigurd Ruschkow said:
No. The reason why I ended up using RN50 (0.25W 3.8mm dark green) and RN55 (0.5W 6mm light brown) Dale resistor was availability at the dealer I got the rest of the parts from.
They are as good as any other metal film I have ever used (Yageo, KOA, etc...). Should I know how difficult is to handle those little 3.8mm critters, I would for sure order another brand from another dealer.
Carbon resistor have one order of magnitude excess noise over metal film, that's easy to measure. Somebody preferring those shows nothing but how much you can rely on subjective testing. Can you imagine that somebody could sell you the carbon resistors as "improved metal film" or "audio quality" resistors?
Sigurd Ruschkow said:
Thanks for forwarding the samples they were just right and I will be posting the results. I thought string theory was now a little out of fashion, and in general it is not that productive to extrapolate the workings of the physics community at the edge of our understanding to listening to two channels of music. Audio seems to be almost the only hobby where the practitioners at a certain level think they are probing the deepest secrets of the universe while trying new cable configurations.
DIY audio is still fun and rewarding if all the physics and science involved is known and explained.
Hi,
Getting a high overload margin with an RIAA preamp using "passive" equalisation can be made with an input transconductance stage loaded by a passsive frequency dependant network.
Instead of being connected to ground, this network can be connected to an virtual ground inverting following stage.
In this way, time constants of the RIAA equalisation can be considered as partly passive and partly active in the virtual ground stage.
Maybe I'm wrong, but I think such a scheme has been used by someone called John Curl.
To complete Ben Duncan's articles on resistors, some EDN articles written by James Bryant
http://www.analog.com/en/amplifiers...-questions/RAQ_lowNoiseAmp/resources/fca.html
http://www.analog.com/en/content/rarely-asked-questions/RAQ_resistors/fca.html
http://www.analog.com/static/imported-files/rarely_asked_questions/moreInfo_raq_opAmpNoise2.html
Each of this link has many other good links.
Getting a high overload margin with an RIAA preamp using "passive" equalisation can be made with an input transconductance stage loaded by a passsive frequency dependant network.
Instead of being connected to ground, this network can be connected to an virtual ground inverting following stage.
In this way, time constants of the RIAA equalisation can be considered as partly passive and partly active in the virtual ground stage.
Maybe I'm wrong, but I think such a scheme has been used by someone called John Curl.
To complete Ben Duncan's articles on resistors, some EDN articles written by James Bryant
http://www.analog.com/en/amplifiers...-questions/RAQ_lowNoiseAmp/resources/fca.html
http://www.analog.com/en/content/rarely-asked-questions/RAQ_resistors/fca.html
http://www.analog.com/static/imported-files/rarely_asked_questions/moreInfo_raq_opAmpNoise2.html
Each of this link has many other good links.
forr said:
James has been a friend for 30yr. he will back up what I say. Extrapolating ultra low frequency thermocouple effects to something audible is a stretch. I wrote a lot of this stuff in the first place and it has been recycled. If you need resistors to make a NIST traceable Kelvin-Varley divider for a laboratory grade transfer standard, yes this stuff matters.
Hi Scott,
Just say "Military" in there somewhere and it will be an audio requirement too. Isn't that the way the party goes?
Fully agree by the way, coming from a metrology background as well.
-Chris
Just say "Military" in there somewhere and it will be an audio requirement too. Isn't that the way the party goes?
Fully agree by the way, coming from a metrology background as well.
-Chris
Allen Wright said:
I can't think of a good reason why a low-noise BJT or JFET input stage couldn't be cascoded with a high voltage CRT driver transistor and operated at 200 or 300V.
scott wurcer said:
I have several KV dividers. They are very difficult to make and the core technologies have not changed much in years. I wouldn't attempt to make one.
The thermal effects on this stuff may not matter but with the desire to have so much gain in the early stages you can exercise all of the servos etc. keeping the output centered. If we are focusing on removing error sources then the impact of thermals (more in the semiconductors than the connections by far) is important. From the references very high DC gain with carbon resistors would be difficult to say the least.
If you need the next best thing to a quantum Hall effect resistor these guys can help Ohm Labs Julie Research designed discrete resistors for very high resolution DAC and ADC stuff before it was on semiconductors. Ohm Labs took over the manufacture of the standards lab resistors from the remaining US makers (except the Fluke stuff). Its much easer to get resistors to track when they share a substrate. These were very difficult to make.
That's precisely the problem.
People have not the slightest idea what physics achieved up to today, most think physicists are still limited to Newton's laws. I certainly can't blame anybody for that as there is no reason people should know better (except if they work in this area).
So building on limited knowledge of today's achievements of understanding the world this gets extrapolated to audio.
I don't have the intention to point at anyone specifically, I'm sorry if that may appear so.
Have fun, Hannes
PS: some of today's regular work in physics:
- build single atomic layers of certain materials (a layer 1 atom thick)
- measure physical properties of melting/evaporating metallic compounds while heating with large currents (megaamperes) within microseconds (thats 1/1000000 of a second), even take a photo
- let individual particles (e.g. electrons) collide in large colliders at velocities close to the speed of light (the limit of all velocities, not reachable for matter)
- laser pulse heating within femtoseconds (1/(12 zeros) of a second)
- cool matter down to nearly (=fractions of a degree) absolute zero (-273.15 C, not achievable due to 3rd law of thermodynamics)
- build plasma chambers containing a plasma as hot as the sun (needs precise magnetic containment as walls of whatever matter would immediately meld)
That it's possible to look at the lattice ordering of atomic structure in matter is already an old story (Bragg reflexions 1915).
syn08, with all respect to you, I love your work and it's exceptionally big source of information. I do not intend to lecture you or something but I just want, in my humble opinion, to point it out to you that there is no need for your high amount of disresepectfulness of other colleges and forum buddies. If you don't agree with someone statement than just comment on it and move on. No need to put provocative and disputable smile symbols.
Cheers
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Cheers
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