it is unbelievable how noisy are the outlets. I did a test in my outlets and they are "ALL" noisy. after using an ac filter from Monster power, almost all the RF noise went away.Too bad most of us just pay attention just to our amp projects and not to the AC source. here is my toy.
Attachments
Neat device, I assume all outlets have a little noise.
My personal view is the amp ends at the power cord. I am not interested in a device that needs filtering before the plug.
I want my amp(s) to sound good wherever they are plugged in.
How much of that noise do you think gets through a well designed power supply?, or are you implying the noise is getting in through the ground?
My personal view is the amp ends at the power cord. I am not interested in a device that needs filtering before the plug.
I want my amp(s) to sound good wherever they are plugged in.
How much of that noise do you think gets through a well designed power supply?, or are you implying the noise is getting in through the ground?
I measured all outlets making sure "NOTHING" was plug into "ALL" outlets in whole apt, not even a lamp. and there were some that were worse than others. for example in my kitchen there was one that I could listened to a radio station clearly. there were some with just loud static noise.
yes, some good circuit can stop RFI.
Noise comes right through even traditional e-core linear supplies. I was amazed how much when I went to measure the ringing of my new rectifier. The noise was greater than the rectifier ringing. You need filtering if you are trying for high fidelity. Very few designers take care of inside the box. They should, but that is the way it is.
I have to rewire my house it is so noisy as the wires were put in around 1951. I have done a few rooms so far, but still have the living room to do as well as the office, so I think you are all very lucky.
How noisy? I think the Nutech meter up there would shake apart from all the oscillations...
How noisy? I think the Nutech meter up there would shake apart from all the oscillations...
this was the first thing that came to my mind when I read that...
Wattgate 381 Audio Grade Duplex Receptacle Outlet 110-439
I think power companies should provide audiophile grade electricity. Build a separate grid, which can only be used by choke input power supplies (so most audio equipment would be excluded - not sure how you would enforce that). The distribution cables could be cryo treated, and made of oxygen-free aluminium. All poles would have to be made of some rare wood which is only grown in Borneo. Insulator strings would need to be made from hand-blown glass.
Otherwise, what is the point of attaching an audiophile-grade socket to an ordinary dirty power source?
Should be a nice little earner for the power companies.
Otherwise, what is the point of attaching an audiophile-grade socket to an ordinary dirty power source?
Should be a nice little earner for the power companies.
Well, all I know is this, apparently it used to be standard practice to have aluminum wire (replaced all that was left in the house), grounding was a wire to the freaking air ducts (is this really all that much of a ground?) instead of the water main/pipe, cloth jacketed wire was big in use back then (ROMEX is soooooo much easier to drag through wood), and at one time between 1951 and now, BX cable was all the rage.
I am pretty sure that most of the un-grounded points are gone and I am slowly getting to the rest. Thank goodness for ranch homes with crawlspace and no finished basements. I am not sure what this will do for noise, but I know I feel safer when my wife is using all four burners on the stove.
I am pretty sure that most of the un-grounded points are gone and I am slowly getting to the rest. Thank goodness for ranch homes with crawlspace and no finished basements. I am not sure what this will do for noise, but I know I feel safer when my wife is using all four burners on the stove.
I've got a pile of line filters from old medical device projects, much like the one John has posted above.....are they useful for line filtering when you have large filter caps and the conduction angles typically found in a SS amp?
I've put them in my flea-powered tube amps, since the current is relatively small compared to SS.....
220vac as a low noise source?
I had read somewhere many years ago that 220vac in the U.S. could be a low noise power source because of the ballanced nature of the voltage source. Each leg being out of phase with the other, much like the ballanced audio lines. The phrase that was used was; common mode rejection. If this is true would it really matter? Could somebody please explain if this is true or not.
I had read somewhere many years ago that 220vac in the U.S. could be a low noise power source because of the ballanced nature of the voltage source. Each leg being out of phase with the other, much like the ballanced audio lines. The phrase that was used was; common mode rejection. If this is true would it really matter? Could somebody please explain if this is true or not.
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