Surprised at Low Household EMI Readings
I picked up a Trifield EMI100 meter to check for EMI noise around the house. After watching a few YT vids I was expecting some pretty high readings. Surprisingly almost everything was low. The unfiltered outlets where my system is plugged in measure less than 10 milllivolts with all equipment powered on. The worst was the bathroom GFCI outlet at around 65mV. I use a 10-year-old Blue Circle power conditioner, and that output is a few mV less than the wall outlet. The house was built around 1970, and outside of a new fuse box installed a few years ago, everything else is original.
Very happy with these readings as I was considering a power conditioner upgrade. The $150 Trifield meter seems to have saved me a few thousand bucks.
I was led to believe that if I had low EMI then my AC power was fairly clean. Others here seem to think otherwise. Please elucidate if this is incorrect. What other nasties live might live in my power and how can they be detected? @sns not talking about RF @ghdprentice no plans to install new lines @dekay or bribed the admins to block you |
Just went around house with my Trifield meter taking readings from various outlets, amongst the outlets measured were whole house, dedicated lines to my audio system, lines coming out of my power conditioner (transformer based), whole house lines with Audio Prism Quiet Line filters. Whole house with or without the filters and dedicated lines measured pretty much the same, lines out of my transformer based PC measured higher.
So, based on these measurements we can deduce my dedicated lines, the filters worthless, and those coming out of PC are less than worthless. Or we can deduce these readings not telling us much of anything. On the other hand, subjectively, these dedicated lines and power conditioning have greatly reduced noise floor of my audio system, a great number of audiophiles report same with their dedicated lines and PC's. One can choose to believe the Trifield meter as the objective arbiter of noise on AC lines or they can choose their senses.
So some |
One of the first things I learned when I started pursuing high end audio was to listen first and... well, over time was to ignore most measurements. There are so many variables that to isolate a couple and attribute the results to them will be too confounding to be helpful. I was trained and professionally a scientist for a decade. If you want to put together a great sounding system then looking for measurements and applying logic, then making purchases is dead end. You will end up with a very mundane uninspiring sounding system. Listen to well seasoned audiophiles and use observation as you primary tool. |
