[FIX] EMI/RFI SOLVED – DIY ICEpower 200ASC/AC Dual Monaural Class D Power Amplifier

I had my DIY ICEpower 200ASC/AC Dual Mono Class D Power Amplifier for 3 months now (March 8, 2020). It is a great piece of kit and definitely a great value vs. performance build. Unfortunately, I have been plagued by Electro Magnetic Interference (EMI) and Radio Frequency Interference (RFI). This led to an annoying intermittent high pitch tone making listening to my music hard to enjoy.

G&W TK-DK 166 Power Conditioner barely made any difference in solving EMI. Local voltage averages between 245-249 VAC.

For starters, there is nothing wrong with the build components. My problem is inherent to my physical location. Singapore is small island and has high density concentration of buildings and supporting infrastructure. Along with that, power grid sub-stations and high powered radio frequency blankets the island. Depending on location, some folks reportedly experienced the same EMI/RFI as I did. I tried a number of things including purchasing a new Power Conditioner (not something I subscribed to) which might have helped just very marginally. Pretty sure my power lines were ‘clean’, I knew my problem source was down to the much dreaded RFI.

To deal with the RFI, I ordered some 20mm and 30mm Copper Insulating Tape from AliExpress. Each roll ran up to 10meters and drew me down less than $10 SGD in total, shipping included. Once my copper tape rolls arrived, it was really about deciding where I should start RFI treatment. Considering my setup, I decided the ICEpower build will be the best place to start and likely demonstrate the most benefit. It was a half-width case and being the last component in my chain before it fed the speakers, I thought it would be a great single end point fix.

20mm Copper Insulation Tape (10meters) – removed amplifier boards and preparing to start taping down the inner side of my amplifier case.

It took a few minutes to open up the case, remove the boards and expose a clean inner case. Next, I started cutting and taping down the copper tape. I am fairly OCD but it was not easy trying not to get wrinkles on the tape. Given this is internal case work, I decided it was something I could live with. Some might think I went a little further than I needed to but I did not want to have to open up the case again. Hence, I pretty much taped down every single panel except for the rear panel.

30mm Copper Tape on the inner Side Panel of my case, trying hard to avoid wrinkles.

Next, I put everything back together and hooked the ICEpower Power Amplifier back into system. Guess what? That high pitch intermittent frequency I have been hearing all this time, gone! Ok, maybe not entirely…but 98% sorted. The remaining 2% is barely audible. To hear that really faint 2%, I need to have my potentiometer at max load and plant my ear next to my speakers.

Copper taped the entire case including the Front Panel which was probably unnecessary. I left a large section of the Top Panel exposed as there were vent holes.

For less than $10 SGD and about 45mins of work, this is a great fix; short of building a faraday cage around my entire setup. If you are having to deal with similar intermittent high pitch frequencies while listening to your music, give this fix a go before shelling out at least 10x the money on a new power conditioner. I might tape down a few short cable runs on the internals of my turntable in the future but I am in no hurry to resolve the final 2% that does not get in the way of enjoying my music. Again, I can be rather OCD about such things but most folks will ignore it entirely.

OCD took over and I did eventually taped down the exposed section on the Top Panel. I did have to pierce through each one of those vents with a tool.

There is one caveat though. As you tape down the copper insulation tape, be sure not to tape over any grounding points. On my DIY GhentAudio case that housed the ICEpower modules, there were a few grounding points. Leave those exposed. I did copper taped my SCHIIT MANI Phono Stage. I was not facing any issues with that but figured it was something I could insulate fairly easily. On my first attempt, i accidentally taped over the the grounding point on the case. That led to loud humming when I switched on the phono stage. Just had to remove the copper tape from that grounding point to rectify the silly mistake.

3 responses to “[FIX] EMI/RFI SOLVED – DIY ICEpower 200ASC/AC Dual Monaural Class D Power Amplifier”

    • You could also try using star quad mic cable (Mogami, Canare, Belden) for internal amplifier wiring, interconnects.

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