DF96, I think you are ON to something important. Maybe, just maybe, you now understand why I would put 2 power resistors, one for each lead, in series with the LED.
It would be interesting to know what kind of frequencies were wreaking havoc with performance here. Then one could try, say, a common-mode choke in the LED wiring... or separate inductors.
EDIT: Or resistors, of course. For a retrofit I'd prefer something from the L department though.
EDIT: Or resistors, of course. For a retrofit I'd prefer something from the L department though.
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This is not new info for me. I read most of the things related to this subject by Jim Brown, Neil Muncy and others and also the NASA study about RF influence on equipment.
Problem is that the wire that connect the speakers to the amplifiers are as much exposed to RF like the wires that connect the LEDs, but the speaker wires do not produce the same problems. I didn't mention that the loudspeaker has two chambers, one for the speakers and one housing the electronics (amps, crossover, balanced receiver). I shielded only the chamber with the electronics. Even if I would want I could not shield the acoustic chamber (maybe with some RF paint). I do not dismiss what you say but considering that the same length of wire is exposed outside the Faraday cage at the speakers I can only think the LEDs are doing something.
One more thing. I have a mastering processor made in US (costs some grands) which is used in some of the best mastering studios and is considered a top device. It is very well designed and constructed (steel case, all XLR connectors with pin1 connected directly to chasis, filtered power, etc). I can create a unique situation where even that device demodulates RF (which is an indicator about how RF problematic is the space I was talking about). I never heard from some fellow engineer who use this device and have this problem. Of course I know what to avoid to create that situation.
chrissugar
Re-connecting with a resistor or a conventional forward-biased diode in place of the LED would narrow the mystery, but probably not worth the effort after all the grief it's already put you through. My money's on injection into the ground, but you've doubtlessly figured something along those lines.
Thanks,
Chris
Chris Sugar has made a valid observation not so much in the defense of John Curl so are some of you going to ridicule him because of it or is refuting everything John Curl says the main sport of the day.
Sometimes I feel that a bunch of you need to grow up................If you disagree say so, state your reasons and move on.
Jam
Sometimes I feel that a bunch of you need to grow up................If you disagree say so, state your reasons and move on.
Jam
John could have articulated his reasoning - stated 2 resistors can give RF/EMI ingress protection
Yes, it illuminates what happens when Prodigy Pro guys copy different parts of different examples of famous equipment mixing them together.
Chris Sugar has made a valid observation not so much in the defense of John Curl so are some of you going to ridicule him because of it or is refuting everything John Curl says the main sport of the day.
Sometimes I feel that a bunch of you need to grow up................If you disagree say so, state your reasons and move on
Jam
Sometimes I feel that a bunch of you need to grow up................If you disagree say so, state your reasons and move on
Jam
To the outside observer it looks like some sort of Vendetta................no pun intended.😉
So Mr.Curl does not want to use an led.........lets not make a federal case out of it.
http://www.youtube.com/watch?v=Tym0MObFpTI
Jam
So Mr.Curl does not want to use an led.........lets not make a federal case out of it.
http://www.youtube.com/watch?v=Tym0MObFpTI
Jam
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3 pin IEC. I tried to disconect the earth pin just to see if it is a case of "standing on one leg" antenna situation (this was the reason I mentioned the room is 25-30meters above earth) but no there was no difference. Also didn't mentioned that before I opened the speakers for inspection I tried to do different power cleaning tricks. Even used an isolation transformer with screen between windings to eliminate the capacitive coupling of RF garbage. No improvement.
This was long ago and finding the problem after so much frustration was such a relief that I didn't bother to check if just desoldering one pin of each LED would solve or not the problem. Of course it was a case of injecting garbage into ground.
What I shared was simply my experience and in no way you should take it like my intention to defend John Curl. Sincerely , although I respect him for what he done in audio, most of the time I find his claims related to various problems being unacceptable.
I think in general, audiophiles observe certain audio phenomenons but most of the time they associate wrong conclusions to the problem.
I do not exclude that my observation that the LEDs were the source of problem is wrong and the wires connecting them were injecting RF into the active speaker but after doing all those tests with ferrites, capacitors etc, it is the only sane reason I can find. But I repeat again, I'm open to accept my conclusion is wrong. Probably one day I will redo the experiment just to see if the LED were the source of problem or the wires
I do not understand what are you talking about. Is this just a cheap shot? I was talking about two devices made by prestigious manufacturers that behave wrongly even if they are not connected to anything only powered.
Most of my mastering tools are designed by myself and very few of them recycle old and good ideas, but mostly they are designed from scratch. And by the way my devices do not produce any problems in that RF polluted environment.
chrissugar
I never did say I agreed with everything Mr.Curl says but but i would not keep attacking him if I disagreed with him.......but beware that you don't find yourself on the wrong side of the fence if you agreed with him.😀
Jam
Jam
I believe you.
Forward biased by 10 mA current diode demodulates RF inside of the box full of semiconductor devices with nanoamp input currents?
Don't make my slippers laugh please. Most probably that innocent LED was soldered to the ground in wrong place, so it's wire acted as antenna.
You should read carefully what I wrote.
1-only one LED of the two is forward biased the other only conduct when there is an over (which never happens)
2-the two LEDs are 20 cm outside the Faraday cage on the wood front panel (not inside the Faraday cage with all the other semiconductors)
3-the speakers (drivers) are connected with 20cm wires to the Faraday cage and they do not induce RF.
chrissugar
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