Boxerfan88 13 Posted November 17, 2020 Share Posted November 17, 2020 (edited) Received my new toy from 11.11 sale. The EMI level was a bit of a shock. Plixir managed to cut it by half. Now to spend time to figure out the source and find a way to overcome the noise. I’m suspecting one of the switching power supply is the culprit. Edited November 18, 2020 by Boxerfan88 Link to post Share on other sites
pcking 4 Posted November 17, 2020 Share Posted November 17, 2020 (edited) For a start, switch off your aircons, next will be LED lights that are not AC direct but uses their own PSUs. Edited November 17, 2020 by pcking Link to post Share on other sites
Boxerfan88 13 Posted November 18, 2020 Author Share Posted November 18, 2020 (edited) Thanks for your advice. AC normally off. Switching off CCFL lamps didn’t help much. Switched off the entire HT/HiFi system didn’t help much. Finally traced the source, it was the PC workstation at the other end of the room powered by another wall socket. With the PC shutdown, the reading dropped dramatically. Its gonna be a tough one to solve. Thats my primary desktop workstation. Edited November 18, 2020 by Boxerfan88 1 Link to post Share on other sites
Dedii 3 Posted November 18, 2020 Share Posted November 18, 2020 (edited) 4 hours ago, Boxerfan88 said: Thanks for your advice. AC normally off. Switching off CCFL lamps didn’t help much. Switched off the entire HT/HiFi system didn’t help much. Finally traced the source, it was the PC workstation at the other end of the room powered by another wall socket. With the PC shutdown, the reading dropped dramatically. Its gonna be a tough one to solve. Thats my primary desktop workstation. I heard using a dedicated MCB line for the audio system would resolve most EMI problem. Maybe try relocate the power source for the desktop if theres an opportunity. Also, may I ask where did you get that EMI measurement device from? Looks interesting! Edited November 18, 2020 by BigAndFat Link to post Share on other sites
jerome_the_lang 4 Posted November 18, 2020 Share Posted November 18, 2020 what purpose buy this emi thingy? use to measure emi? and then what, knowing emi is high or low? Link to post Share on other sites
Dedii 3 Posted November 18, 2020 Share Posted November 18, 2020 6 minutes ago, jerome_the_lang said: what purpose buy this emi thingy? use to measure emi? and then what, knowing emi is high or low? I believe its an indication of EMI in the power source (power to noise ratio). From what ive read online, under 50mv its very good and more than 1500mv would be very poor. And also see if using a power conditioner improves the EMI . . Link to post Share on other sites
jerome_the_lang 4 Posted November 18, 2020 Share Posted November 18, 2020 (edited) On 11/18/2020 at 4:49 PM, BigAndFat said: I believe its an indication of EMI in the power source (power to noise ratio). From what ive read online, under 50mv its very good and more than 1500mv would be very poor. And also see if using a power conditioner improves the EMI . . ok, keep us updated of your progress. BTW, it will be complementary to read about magnetic field measurements of audio components and what detrimental effects they can imposes on other audio components, and cables in close proximity. power conditioners, in particular, radiate very strong magnetic fields. dun let the cure be worse than the disease..... . Edited November 20, 2020 by jerome_the_lang Link to post Share on other sites
Boxerfan88 13 Posted November 18, 2020 Author Share Posted November 18, 2020 (edited) 3 hours ago, BigAndFat said: I heard using a dedicated MCB line for the audio system would resolve most EMI problem. Maybe try relocate the power source for the desktop if theres an opportunity. Also, may I ask where did you get that EMI measurement device from? Looks interesting! Thank you for the advice. Unfortunately at this time, I am unable to install a dedicated line from the MCB to the room, therefore I have to find another solution. I bought the item from Aliexpress. You might be able to land a good price during the black friday sale. Stack some coupon and you should be able to get it below $90. I was lucky to catch their shipping window, therefore received the unit within a week. Link below: https://a.aliexpress.com/_mP328Nf Edited November 18, 2020 by Boxerfan88 Link to post Share on other sites
pcking 4 Posted November 19, 2020 Share Posted November 19, 2020 (edited) @Boxerfan88 Out of curiosity, which PSU is your desktop PC using ? Edited November 19, 2020 by pcking Link to post Share on other sites
jtsamarinda 7 Posted November 19, 2020 Share Posted November 19, 2020 21 hours ago, BigAndFat said: I heard using a dedicated MCB line for the audio system would resolve most EMI problem. Maybe try relocate the power source for the desktop if theres an opportunity. Also, may I ask where did you get that EMI measurement device from? Looks interesting! IMO there is a mis- conception that by having a dedicated line for your system setup solves the problem. It does not, remember your dedicated line is just a tap off from your main input ( Which is the 63 amp isolator) coming into the house. And by hook and crook the power line are all connected by your breaker or MCB so it does not solve the problem of EMI. So I see many of my client waste lots of money thinking that it helps. It does not. Put your EMI meter through the test and find out after wasting all that money on dedicate line. Link to post Share on other sites
Colossus 3 Posted November 19, 2020 Share Posted November 19, 2020 do you enjoy the music better with low EMI? sorry if this is a stupid question.😁 Link to post Share on other sites
Boxerfan88 13 Posted November 19, 2020 Author Share Posted November 19, 2020 (edited) 56 minutes ago, Colossus said: do you enjoy the music better with low EMI? sorry if this is a stupid question.😁 This is a very very valid question. I am already happily enjoying my system with high EMI for years. I have a feeling my source & integrated amp does a very very good job of blocking/rejecting EMI therefore the system has been sounding very nice for years. When I got the EMI tool, and showing a high reading, its just the itchy backside wanting to do something about it. 😅 Edited November 19, 2020 by Boxerfan88 Link to post Share on other sites
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