some people realize what "sounds" are loudspeakers in rooms - and that's where any serious about improving recorded music playback should be putting time and $
this is also the position of Psychoacoustics researchers, text book writers on the subject - intentionally accurate electronics is given little weight compared to transducers, acoustic characteristics of the environment
but some of us have the training, experience in electronics and can appreciate the "conceptual art" of circuit designs that we don't expect actually have actually audible consequence in controlled listening
this is also the position of Psychoacoustics researchers, text book writers on the subject - intentionally accurate electronics is given little weight compared to transducers, acoustic characteristics of the environment
but some of us have the training, experience in electronics and can appreciate the "conceptual art" of circuit designs that we don't expect actually have actually audible consequence in controlled listening
That's a "biggie" - post 21'st century problem (below).
Man , there is a lot of EMI out there (below 2).
I saw this with my first 20mhz scope , unplugged PC's and mobile device
switchers to see it reduced - but could not eliminate it.
I'm now running through a IEC line filter and also have my lifted ground
with active filtering. Not too bad if there are no cheap asian CFL's or
mobile charger PS's (on the strip).
By being a PC -analog mix for my system means I can't use a separate
household circuit for digital/analog (ground loop) Optical might allow this.
OS
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I choose to interpret John Curl's remarks to mean: go ahead and listen, it won't hurt you and you might be surprised by what you hear.
Certainly I can imagine high-end company X ordering ten blank PCBs of their new prototype amplifier. Board #1 is stuffed with Vishay/Dale brand resistors. Board #2 is stuffed with Roderstein brand resistors. Board #3 is stuffed with Holco brand resistors. Board #4 is stuffed with Ohmite brand resistors. And then: they listen. Maybe they hear differences. Maybe they hear superiority or inferiority. At least they were open minded enough to try. And even if they don't hear any differences at all, even if they choose a vendor based on coin flips, they can truthfully proclaim that ABCDE brand resistors were chosen after extensive listening tests. Be open minded, give it a listen. What can it hurt?
Certainly I can imagine high-end company X ordering ten blank PCBs of their new prototype amplifier. Board #1 is stuffed with Vishay/Dale brand resistors. Board #2 is stuffed with Roderstein brand resistors. Board #3 is stuffed with Holco brand resistors. Board #4 is stuffed with Ohmite brand resistors. And then: they listen. Maybe they hear differences. Maybe they hear superiority or inferiority. At least they were open minded enough to try. And even if they don't hear any differences at all, even if they choose a vendor based on coin flips, they can truthfully proclaim that ABCDE brand resistors were chosen after extensive listening tests. Be open minded, give it a listen. What can it hurt?
OS,
I just replaced four rows of florescent bulbs with LEDs that are so much brighter, use 1/4 the power and got to remove the ballast at the same time. Get rid of those nasty florescent bulbs and save some power. I would think you should be able to filter out the smps power supplies on the power lines, wouldn't a pass filter remove that high frequency noise on the lines? RNM seems to be one of the power supply gurus on this thread.
I just replaced four rows of florescent bulbs with LEDs that are so much brighter, use 1/4 the power and got to remove the ballast at the same time. Get rid of those nasty florescent bulbs and save some power. I would think you should be able to filter out the smps power supplies on the power lines, wouldn't a pass filter remove that high frequency noise on the lines? RNM seems to be one of the power supply gurus on this thread.
John, as one who has lived with power line filters for 15 years now, and have sold them in 28 countries in the world, I said it before and I say it again - when filters work, they can work very well, but in other instances the benefits are small and not nearly worth the money asked in most cases. There are a few variables which are critical, yet you can't do a thing about them. For example, if you live in a sparsly populated neighborhood right next to the local distriuting station with brand new power transformes you will probably not need one, and conversly, if you live in a big apartment block and are near the last place served with power, you will almost certainly benefit from a decent filter,
An while prices do vary widely, I disagree you need to pay an arm and a leg for a decent system, meaning that it must cost you less than $1k with separate filters for at least 4 outputs. This invites comparisons of different filter approaches, and the good ord knows there are many of them.
Yet, because of the numerous unknown variables, nobody should pay a red cent for any unit he has not tried at home for at least 2 weeks, that's the ONLY reliable way to really KNOW whether you actually need one. A free hands-on trial run or your money back, as simple as that. If you have a solid product on your hands, you won't be getting many of them back, in 15 years and after hundreds of units, I only one got one sent back to me from France, ne'er one from Canada, and I sold a lot of them in Canada. Or from Holland, or from Germany, and those three were my main markets. Some video(audio studios from Holland bought a number of times.
And it is not a luxury in cramped urban areas, belive me, it has become a necessary evil, a need, especially if you own tube gear. Assuming a fair price, which is not in the peanut class, but has to stay below $1K and must be able to do its thing even with behemoths like offerings from Krell and Levinson.
An while prices do vary widely, I disagree you need to pay an arm and a leg for a decent system, meaning that it must cost you less than $1k with separate filters for at least 4 outputs. This invites comparisons of different filter approaches, and the good ord knows there are many of them.
Yet, because of the numerous unknown variables, nobody should pay a red cent for any unit he has not tried at home for at least 2 weeks, that's the ONLY reliable way to really KNOW whether you actually need one. A free hands-on trial run or your money back, as simple as that. If you have a solid product on your hands, you won't be getting many of them back, in 15 years and after hundreds of units, I only one got one sent back to me from France, ne'er one from Canada, and I sold a lot of them in Canada. Or from Holland, or from Germany, and those three were my main markets. Some video(audio studios from Holland bought a number of times.
And it is not a luxury in cramped urban areas, belive me, it has become a necessary evil, a need, especially if you own tube gear. Assuming a fair price, which is not in the peanut class, but has to stay below $1K and must be able to do its thing even with behemoths like offerings from Krell and Levinson.
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You have to look at very high end audio gear to see if they use a AC line filter.
All my HP test equipment uses them
I think one Pioneer Exclusive Class amp had one. You would think they would be used in high end pre-amps more often, since they do not draw much power.
CFL I agree can be replaced with LED.
I have been to factories where they had ~2000 4-lamp T5HO fixtures, 40 ft up.
I do not see LED replacing this sort of installation in the near future.
LEDs are still very expensive. I use a T5HO lamp as a comparison, they give out ~5000 initial lumens for less than $10. The lumen depreciations is less for a T5HO than a LED. What are you paying for 5000 lumens of led light? I bet way more than $10.
BTW a LED power supply front end is very similar to a modern fluorescent ballast, they all use a PF corrected front end ckt. LED PS has a pwm for the back end, basicvally a constant current ckt, where the FL ballast uses a oscillator for a h-bridge and transformers, some Xc.
All my HP test equipment uses them
I think one Pioneer Exclusive Class amp had one. You would think they would be used in high end pre-amps more often, since they do not draw much power.
I do not know why you say that, is it the mercury? Both use rare earth elements.
CFL I agree can be replaced with LED.
I have been to factories where they had ~2000 4-lamp T5HO fixtures, 40 ft up.
I do not see LED replacing this sort of installation in the near future.
LEDs are still very expensive. I use a T5HO lamp as a comparison, they give out ~5000 initial lumens for less than $10. The lumen depreciations is less for a T5HO than a LED. What are you paying for 5000 lumens of led light? I bet way more than $10.
BTW a LED power supply front end is very similar to a modern fluorescent ballast, they all use a PF corrected front end ckt. LED PS has a pwm for the back end, basicvally a constant current ckt, where the FL ballast uses a oscillator for a h-bridge and transformers, some Xc.
Actually, Coldhead, normal surge protectors like MOV's can actually DEGRADE the sound quality of a good audio system. That is why we chose Gas filled tube protectors instead. Much more linear. See, I just gave away a 'proven' design secret. '-)
It isn't easy to make a line filter that does not change the sound in a negative way. Many people just note a change, but others note what sort of change.
It isn't easy to make a line filter that does not change the sound in a negative way. Many people just note a change, but others note what sort of change.
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I am using one of those network extenders that sends the internet signal down the power cables in my house. They are very, very noisy. Crud comes right through the power supply and also radiated from the box that plugs into the mains sockets. Be warned. Cheap CFL's and LED lamps - yes - also not good if you are trying to work on low noise electronics.
I noted while trawling through the internet a few weeks ago that UK hi-fi brand 'Roksan' have pictures of some of their gear with what looks like a very expensive line filter. I am wondering if they also had issues with EMI in general and decided to take the high road.
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This is simple untrue.
Engineers are trained to understand and to operate with problems in technic. Understanding problems eliminate random "trying" to do some unusual experiments. And involve some goal predictions in work.
Audio designers are some kind of system-integrators, but engineers knowledge, or scientifical, is necessary...
Excluding morphology of listening.
Or to include some "magic"...this is specific way..
Interesting, while I was in Japan, I could not find silicone sealer - you know, the one that cures quite firmly and sticks like hell. All I could get was some cheap crud no matter where I looked. Eventually I surmised it was perhaps a patent issue and the good stuff was prevented from hitting the shelves in Japan. There are a few cases of this across various industries over there. Another area is pharma I hear.
However, I sure would like to know why there is no decent silicone sealer in Japan.
Yes LED lamps could be EMI-quiet but I don't know of any that are.
My personal lab is in my apartment and the line noise has been hideous for the last few years. J. Johnston suggested, in a Facebook exchange, that what I see on the scope at ~5mV/div was from switching power supplies, but I said I figured I knew by now what that looked like---and this was more indicative of something involved in data transmission. It isn't from CFL ballasts as I eliminated those, and I have a couple of LED lamps now but their operation does not affect the noise. I use an incandescent for bench light and powered from a variable transformer.
Let us hope that the physiological effects of the greatly-increased levels of RF almost everywhere are not as bad as some alarmists claim. But I recall Casandra was right.
My personal lab is in my apartment and the line noise has been hideous for the last few years. J. Johnston suggested, in a Facebook exchange, that what I see on the scope at ~5mV/div was from switching power supplies, but I said I figured I knew by now what that looked like---and this was more indicative of something involved in data transmission. It isn't from CFL ballasts as I eliminated those, and I have a couple of LED lamps now but their operation does not affect the noise. I use an incandescent for bench light and powered from a variable transformer.
Let us hope that the physiological effects of the greatly-increased levels of RF almost everywhere are not as bad as some alarmists claim. But I recall Casandra was right.
Momentive manufactures in Japan, ditto Shin Etsu and Toshiba. I'd guess either just consumer preference or local regulation. Patents for "the good stuff" are long past.
Coldhead, what kind of education do you think that I have? I have a degree in Physics with a minor in electrical engineering, as well as years of extra courses in electronic design (to fill in) from UC Berkeley, etc. Then again, 50 years of design experience on top of that. I just happen to be especially good at audio design, because I like it, and I keep an open mind, but I have been a SR Electronics Engineer at a company of 300 people doing medical electronics in the past. What do you want?
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CQUOTE=bcarso;4714753]Yes LED lamps could be EMI-quiet but I don't know of any that are.
My personal lab is in my apartment and the line noise has been hideous for the last few years. J. Johnston suggested, in a Facebook exchange, that what I see on the scope at ~5mV/div was from switching power supplies, but I said I figured I knew by now what that looked like---and this was more indicative of something involved in data transmission. It isn't from CFL ballasts as I eliminated those, and I have a couple of LED lamps now but their operation does not affect the noise. I use an incandescent for bench light and powered from a variable transformer.
Let us hope that the physiological effects of the greatly-increased levels of RF almost everywhere are not as bad as some alarmists claim. But I recall Casandra was right.[/QUOTE]
Could well be you have data transmission on the power line causing your problem. I had a terrible time in Taiwan at the one house I stayed at and now surmise that this was the cause - but as to the source, I have no clue.
In my case, my Tek scope is showing a 23MHz signal.
My personal lab is in my apartment and the line noise has been hideous for the last few years. J. Johnston suggested, in a Facebook exchange, that what I see on the scope at ~5mV/div was from switching power supplies, but I said I figured I knew by now what that looked like---and this was more indicative of something involved in data transmission. It isn't from CFL ballasts as I eliminated those, and I have a couple of LED lamps now but their operation does not affect the noise. I use an incandescent for bench light and powered from a variable transformer.
Let us hope that the physiological effects of the greatly-increased levels of RF almost everywhere are not as bad as some alarmists claim. But I recall Casandra was right.[/QUOTE]
Could well be you have data transmission on the power line causing your problem. I had a terrible time in Taiwan at the one house I stayed at and now surmise that this was the cause - but as to the source, I have no clue.
In my case, my Tek scope is showing a 23MHz signal.
Scope pics
I have seen the difference on a CD player's output with and without a clamp on ferrite filter on the AC cord. At that time I figured this come from a near by (2.5km) TV transmitter tower, with multiple VHF and UHF stations.
I have seen the difference on a CD player's output with and without a clamp on ferrite filter on the AC cord. At that time I figured this come from a near by (2.5km) TV transmitter tower, with multiple VHF and UHF stations.
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