Yeah, I was sitting inside a Motorola plant when I typed that, and "big brother" monitors all internet, email, and even telephone traffic. I have 6 Agilent RF signal generators, 2 spectrum analyzers, a network analyzer, a complex signal analyzer, and dozens of the usual support pieces like scopes and power supplies. This is just the stuff that sits on my workbench, new cost, probably $350K. There are 15 of us with similar workbenches that are somewhat tailored to the individuals particular RF specialty. I am the guy that glues all of the individual circuits together to make a two way radio, so I have receiver, transmitter, power supply, and some digital equipment. Then there is the lab. There is an easy $1M of equipment in there.
Yes, it is especially unusual since I can see the 300 foot tall Plantation police radio tower from my window and I am developing two way radio equipment for police use. We have two RF screen booths for use by whoever feels like dragging their equipment in and setting up, but they are hot and poorly lit, so I sit by the window. I have to be real careful as to what frequency I use for testing when firing up a 100 watt transmitter.
The thread was about power cords. What can you test on a power cord that can't be done with simple equipment. I did admit that some shielded line cords may offer some protection from noisy environments in poorly designed equipment. I also explained my electric drill test for amplifiers which got nowhere. The thread degenerated to the fact that I could not hear the difference between a $2 cord and a $200 cord was because my speakers were not revealing enough. Fact or not, it doesn't matter to me, since I am not going to spend $200 on a power cord. I do know several respected engineers who have though, speaker wire too.
I know how to set up a proper listening test, and have even run a few. But since the layoffs and the economic fallout our group of audiophiles and tubeheads have all been scattered across the country. I doubt that I could organize anything on even a reasonable notice.
It is fairly easy to set up a test with two suitable RF connectors mounted to a piece of copper clad board. The set up is calibrated with a piece of wire. The network analyzer is attached to each connector and a "full two port" calibration run to take the setup out of the picture. The device to be tested is installed in place of the wire and a two port analysis is run. This will measure transmission and reflection characteristics at each end. Short explanation....what got through the DUT, and what was rejected at each end.
The network analyzer on my desk was actually rescued from the scrap department. It only goes from 300 KHz to 3 GHz and only has 70 db of dynamic range. We have better ones in the lab!
Chris, there are several ways to measure the resistance. Easiest is to run a constant current through it and measure the voltage- the current rating is something like 4 amps, so a 1 amp CCS is more than enough to get a very accurate reading. Having a reference resistor will help a lot.
According to my source, there is an actual resistor inside.
According to my source, there is an actual resistor inside.
Hi exeric,
Firstly, the best equipment doesn't sound exactly like the original sound. You accept the system as it is in order to be able to enjoy what you do hear. It only depends on what shortcomings you can forgive in that case.
Secondly, only someone with something to lose would bury their head in the sand like that. History shows time and time again that a truth tends to come out where it involves material science. Only a stupid person believes they can hide the truth. Delaying it for financial gain is another matter all together. Neither SY or George have any reason to hide anything. They both have reputations to protect, and that reputation is their honesty. Once you lose that, you have nothing.
In this situation, I don't believe you would have anything to fear. Results and methods will be open to examination and recreating the experiments. I believe that these gentlemen will be very happy to find anything unusual. At the very least, I expect these devices will be fully characterized. The actual transfer function can be found. Knowing this would then allow for a real ABX test since the transfer characteristics should be able to be duplicated. Then the constructed item can be compared to the real device. Now that will be interesting!
-Chris
You and I both. The cornerstone of any science is honesty, and that includes saying "I don't know". The facts can always be sorted out at a later date. This type of thing also spurs investigation into what can't be measured (or recognized) so that answers can be had in the future.
Two views to that comment as it applies to two different situations.
Firstly, the best equipment doesn't sound exactly like the original sound. You accept the system as it is in order to be able to enjoy what you do hear. It only depends on what shortcomings you can forgive in that case.
Secondly, only someone with something to lose would bury their head in the sand like that. History shows time and time again that a truth tends to come out where it involves material science. Only a stupid person believes they can hide the truth. Delaying it for financial gain is another matter all together. Neither SY or George have any reason to hide anything. They both have reputations to protect, and that reputation is their honesty. Once you lose that, you have nothing.
In this situation, I don't believe you would have anything to fear. Results and methods will be open to examination and recreating the experiments. I believe that these gentlemen will be very happy to find anything unusual. At the very least, I expect these devices will be fully characterized. The actual transfer function can be found. Knowing this would then allow for a real ABX test since the transfer characteristics should be able to be duplicated. Then the constructed item can be compared to the real device. Now that will be interesting!
-Chris
Hi George,
Can you rescue another from the scrap heap????
I'm sure you can't possibly get involved with that, but a guy can dream, can't he? I have an old Wiltron 560A that doesn't seem to be going anywhere fast. No sensors.
Hi SY,
Heating effects from that current flow should be characterized separately if possible. High current was my initial thought. Wouldn't you just hate to exceed the ratings before you even get started testing?
Most DVMs are weak in the resistance and current accuracies. The accepted method is to run a known current through the device (kelvin again) and measure the voltage drop. But here I'm thinking that a comparison method where the Bybee is the unknown might be more accurate. If you get them balanced, you can merrily exceed the ratings of your equivalent resistance without any loss other than the time it took. The Bybee survives to clean up electrons on another day.
I wonder. Would one of these clean the glitches up from a D/A converter before the I/V step? Or would it mute everything since it all looks like terrible hash. Devices have no idea what the desired signal is, or what circuit they are installed in. All they "know" is what appears across their terminals.
-Chris
Can you rescue another from the scrap heap????
I'm sure you can't possibly get involved with that, but a guy can dream, can't he? I have an old Wiltron 560A that doesn't seem to be going anywhere fast. No sensors.
Hi SY,
Heating effects from that current flow should be characterized separately if possible. High current was my initial thought. Wouldn't you just hate to exceed the ratings before you even get started testing?
Most DVMs are weak in the resistance and current accuracies. The accepted method is to run a known current through the device (kelvin again) and measure the voltage drop. But here I'm thinking that a comparison method where the Bybee is the unknown might be more accurate. If you get them balanced, you can merrily exceed the ratings of your equivalent resistance without any loss other than the time it took. The Bybee survives to clean up electrons on another day.
I wonder. Would one of these clean the glitches up from a D/A converter before the I/V step? Or would it mute everything since it all looks like terrible hash. Devices have no idea what the desired signal is, or what circuit they are installed in. All they "know" is what appears across their terminals.
-Chris
Anatech,
20 milli-ohm level resistance measurements are fairly easy to make and SY should have no trouble with that at all. I used to build PMBDC electric motors with phase resistances in that range and the 1A CCS method works well for that. (micro-ohm measurement is another story altogether). Its hard to believe that the 25 mW dissipation would cause any difficulties.
20 milli-ohm level resistance measurements are fairly easy to make and SY should have no trouble with that at all. I used to build PMBDC electric motors with phase resistances in that range and the 1A CCS method works well for that. (micro-ohm measurement is another story altogether). Its hard to believe that the 25 mW dissipation would cause any difficulties.
I measure such low impedances with the constant current method withou any problems. I am designing and building a dipole ribbon tweeter at the moment so i had to come up with a way to measure tiny impedances. Helped me also to determine wire length and gage when i tested Salas Shunt Regulators. To measure the parsitics may be less easy. By the way CJ already mentioned that there is a beryllium resistor inside so no wounder the guy found a resistor by cracking it open.
He would know because he bought one and disassembled it. He was even nice enough to send photos.
You don't have to trust him. You don't even have to trust me. Just repeat the measurements I present and if I made an error or if they're not replicable, well, have at me.
Well, what I'd really like to know is why they call it a resistor just because it has some resistance. Almost all components have some measure of resistance, even capacitors. But that doesn't mean the primary effect is caused by the resistance. Just because its tubular shaped and has a small resistance does not by any stretch of the imagination mean that the primary effect is simply caused by its resistance. I think everyone should start thinking out of the box and we might actually get to a point where we can measure the parameter that is actually causing the effect. Commonsense says this mystery would never have lasted this long if it was a consequence of just being resistance. I can tell you that in my system no tiny resistor could cause the effect I'm hearing.
Doh!!! I forgot. None of you have actually tried them in your system playing music.
The claimed audible effects of this device are so great that I doubt anyone should have a problem hearing something. Even if measurements turn up nothing of note.
If measurements do turn up changes that might be due to simple LCR in the path, a "Fauxbee" of the same value could be inserted in the path to test if a difference can be heard between the two. Or even measured
But that's getting ahead of the game. Good measurements will certainly show something - we just don't know what that is yet.
If measurements do turn up changes that might be due to simple LCR in the path, a "Fauxbee" of the same value could be inserted in the path to test if a difference can be heard between the two. Or even measured
But that's getting ahead of the game. Good measurements will certainly show something - we just don't know what that is yet.
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