Well, there are some truly massive turntables out there. But all of them are used with conventional low mass tone arms fully exposed to airborne vibrations. You'd think these $100,000 turntables would be topped with a big bell jar to isolate the arm/cartridge from airborne vibration after putting hundreds of pounds of metal into the turntable.
se
SE,
Those insane turntables with huge mass seem to be most concerned with speed control and using the high mass to keep speed constant. Funny that they don't also have a clamping system to tie the vinyl to that moving mass sometimes. A bell jar with a vacuum attachment would solve all the other problems one may think up.
Those insane turntables with huge mass seem to be most concerned with speed control and using the high mass to keep speed constant. Funny that they don't also have a clamping system to tie the vinyl to that moving mass sometimes. A bell jar with a vacuum attachment would solve all the other problems one may think up.
Well, It has been a while. I decide that since MS was no longer supporting XP I would try a different anti virus program. My main computer has serial and parallel ports along with a floppy disc drive. That is because it runs my machine tools and has bits of very old software.
So for the first week the Avast software seemed to do a nice job. I ran the weekly full disc scan and it "found" viruses in some of the MS download managers. The next day I started my computer and went out to review a new installation. When I got back I found all of the standard file types were deleted, not hidden. A system restore said nothing had changed and restored nothing. As I did not know for sure when the virus loaded I consider my backups may also have it.
It seems to have come in via MS Outlook as a JPEG file. So I pulled the hard drive and inserted it into an old machine I was rebuilding to become a Black and White TV. (1T hard drive, new DVD drive and reloaded minimum operating system software.) Using a file recovery program with a filter I recovered 1200 files. I did seem to lose a lot of my OWON, AP, and Express PCB Files. As most of these were untouched by the virus I may still recover them. I did get the PC files but not the custom files.
So my old computer will be in general use for the next day or so. Then it becomes a legacy software only system.
Now as to old camel dung. I have attached an image of the results of a single audio interconnect in the forward and reverse directions. As the investigation target is around 3,000 Hz, most folks can note the increase in noise floor from this repeatable measurement. Dimitri as you can see the cure changes with cable changes and it is "noise" that is the issue so it is not what would be expected from an op amp issue. Scott, note that the test signal is 15 millivolts and the loop area is a meter. Testing capacitors at a few volts is a much easier task.
Now next up are two Time domain Reflectometer images. A TDR quickly inserts a charge into a cable and then looks at the voltage vs time. As you can see on a shorted cable after a brief delay the voltage drops below the zero level as the charge that went out on one conductor is returned on the other. In the other image the charge takes more time to return and it is not inverted as it returns on the same conductor. NOW during the time the charge is propagating there is more charge in the cable that at rest or equilibrium.
I have tried to explain why I believe at low current levels charges do not propagate the same as at higher levels due to the decrease in intercharge reaction from the inserted charges. My opinion is that is why there is varience in the actual charge transit path, which cause a variance in the current flow and shows up as noise.
Now as to the clock problem, it is much easier if you ask the right question. If the minute hand covers 360 degrees in 60 minutes and the hour hand moves at 1/12 the speed, when is the minute hand 120 degrees ahead of the hour hand? Two simple linear algebra equations! It is not a matter of smarts, rather viewpoint.
Finally the argument over power transformer size. The first issue is what are you powering? A power amplifier has a voltage gain of maybe 30. Jan's preamps probably only need a gain of 1! However John's phono preamps require a gain of 1000 or more! So what you are powering is a big factor.
Now for power amplifiers an 8 ohm loudspeaker may have a minimum impedance of 4 ohms according to the standard. It will also have a back EMF. In a very efficient loudspeaker this could have enough effect to again halve the minimum impedance. However in real loudspeakers this would be a maximum of another 30%. So if you size your power transformer to drive a 2.8 ohm load you should be fine.
Now if you look at the transformer noise images you can see that small power transformers have cores that are driven farther into saturation than larger cores! That is because they are able to dissipate heat a bit better than larger ones. So when you up size the transformers you get less distortion. They also tend to have less line noise coupling. Now I also show the conduction angle for large and small transformers. A large transformer lets less line noise in than a small transformer.
Now there are other techniques I have show to reduce common mode noise by using four secondary windings.
The conclusion is that larger transformers do have a place in high gain audio circuits. (The wise may look at using a 240 volt primary on a 120 volt line with four output windings!)
ES
So for the first week the Avast software seemed to do a nice job. I ran the weekly full disc scan and it "found" viruses in some of the MS download managers. The next day I started my computer and went out to review a new installation. When I got back I found all of the standard file types were deleted, not hidden. A system restore said nothing had changed and restored nothing. As I did not know for sure when the virus loaded I consider my backups may also have it.
It seems to have come in via MS Outlook as a JPEG file. So I pulled the hard drive and inserted it into an old machine I was rebuilding to become a Black and White TV. (1T hard drive, new DVD drive and reloaded minimum operating system software.) Using a file recovery program with a filter I recovered 1200 files. I did seem to lose a lot of my OWON, AP, and Express PCB Files. As most of these were untouched by the virus I may still recover them. I did get the PC files but not the custom files.
So my old computer will be in general use for the next day or so. Then it becomes a legacy software only system.
Now as to old camel dung. I have attached an image of the results of a single audio interconnect in the forward and reverse directions. As the investigation target is around 3,000 Hz, most folks can note the increase in noise floor from this repeatable measurement. Dimitri as you can see the cure changes with cable changes and it is "noise" that is the issue so it is not what would be expected from an op amp issue. Scott, note that the test signal is 15 millivolts and the loop area is a meter. Testing capacitors at a few volts is a much easier task.
Now next up are two Time domain Reflectometer images. A TDR quickly inserts a charge into a cable and then looks at the voltage vs time. As you can see on a shorted cable after a brief delay the voltage drops below the zero level as the charge that went out on one conductor is returned on the other. In the other image the charge takes more time to return and it is not inverted as it returns on the same conductor. NOW during the time the charge is propagating there is more charge in the cable that at rest or equilibrium.
I have tried to explain why I believe at low current levels charges do not propagate the same as at higher levels due to the decrease in intercharge reaction from the inserted charges. My opinion is that is why there is varience in the actual charge transit path, which cause a variance in the current flow and shows up as noise.
Now as to the clock problem, it is much easier if you ask the right question. If the minute hand covers 360 degrees in 60 minutes and the hour hand moves at 1/12 the speed, when is the minute hand 120 degrees ahead of the hour hand? Two simple linear algebra equations! It is not a matter of smarts, rather viewpoint.
Finally the argument over power transformer size. The first issue is what are you powering? A power amplifier has a voltage gain of maybe 30. Jan's preamps probably only need a gain of 1! However John's phono preamps require a gain of 1000 or more! So what you are powering is a big factor.
Now for power amplifiers an 8 ohm loudspeaker may have a minimum impedance of 4 ohms according to the standard. It will also have a back EMF. In a very efficient loudspeaker this could have enough effect to again halve the minimum impedance. However in real loudspeakers this would be a maximum of another 30%. So if you size your power transformer to drive a 2.8 ohm load you should be fine.
Now if you look at the transformer noise images you can see that small power transformers have cores that are driven farther into saturation than larger cores! That is because they are able to dissipate heat a bit better than larger ones. So when you up size the transformers you get less distortion. They also tend to have less line noise coupling. Now I also show the conduction angle for large and small transformers. A large transformer lets less line noise in than a small transformer.
Now there are other techniques I have show to reduce common mode noise by using four secondary windings.
The conclusion is that larger transformers do have a place in high gain audio circuits. (The wise may look at using a 240 volt primary on a 120 volt line with four output windings!)
ES
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How would you know, saw it in a text book ....
There is a clamping system ....
So there's a Russian audiophile posse too? Sounds like being built like a wrestler would help.
BTW there is backround seismic noise that is always easily measurable by the right lab equipment so the statement that there is improvement even without measurable vibration makes no sense.
Ed, you simply don't understand the basics at times. I for one am tired of these discussions. Maybe jn wants to elaborate on the differences between the EM wave and charge.
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Seriously powercord?
Yeah those sighted "tests" sure are conclusive Not one ounce of bias in those
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Seriously powercord?
Yeah those sighted "tests" sure are conclusive Not one ounce of bias in those
Bias , projecting ...... ?
Here are some sentences from a review on a role of the defects on conductivity mechanisms
"The crystal dislocations, arising from the plastic deformation, appreciably alter the electrical properties of both metals and semiconductors and dielectrics. This is determined by the fact that, in such crystals, not only the carrier mobility , but also their concentration can vary considerably under the influence of dislocations. Some techniques for direct experimental study of the electric fields and local changes in the electronic properties of the crystal generated by individual dislocations in semiconductors and insulators have been developed. In the case of metals, such task is more complicated ( there are no major changes since the publication of reviews [ 2, 3] ) . It is only necessary to note the intensification of studies of the effect of dislocations on superconductivity [135]. Development of methods of observation of electron vortices in type II superconductors allows to hope for progress in the development of direct methods for the study of their interaction with dislocations."
Nobody can state that metals conduct independently of lattice defects. Moreover, real copper has polycrystalline structure, with many internal boundaries with different conductivity properties.
One should simply admit, that rigorous prooving of a kind of effects indicated by Ed Simon can take a whole life, but this is probably not a task for electrical engineer.
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None of this has anything to do with conservation of charge, violated by Ed's comment. A pulse propagating on a transmission line is not a packet of charge.
Please stop this nonsense, the circuit is completed at the source, the charge at the output is immediately equaled at the ground return. There is no packet of charge accellerated to c shot out the end of the generator.
I have tried the ball bearing analogy and the charge one. If you want the charge version you are sending one polarity out one line and the other the return line and they pass in the night.
I could try the banging on the metal rod one also, that is a true wave propagation! Perhaps the old fashioned movie sound track with variable density?
A big wave washes over rocks, a small one goes around.
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