I had completed THE BUILD of 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 Electromagnetic Interference (EMI) and Radio Frequency Interference (RFI). This led to an annoying intermittent high pitch tone making listening to my music hard to enjoy.
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 substations 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 rerouting my mess of power and signal cables and finally ended up purchasing a new Power Conditioner again (not something I subscribed to). I did a few years back had a Furutech e-TP80 which I shelled out good money for new but frankly was unable to hear a noticeable difference.
The new G&W TW-DK166A at 25% of what the Furutech e-TP80 cost was not any different and at best, might have helped just very marginally. The only upside was I now could see the voltage running from the wall, had additional universal inlet plugs which were a very tight fit for UK plugs side by side. If one was running predominantly UK plugs, I find the PermaPlug 4-Gang Power Distributors one of the best options. Very well built, and user choice termination. I have mine terminated with Belden 19364 Power Cords and MK UK Plugs. End of it all, I was pretty sure my power lines were ‘clean’ and 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 10 meters 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.
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.
Next, I put everything back together and hooked the ICEpower Power Amplifier back into system. Guess what? That intermittent high pitch 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. I do not listen to my music with volume pot at max ever for starters.
For less than $10 SGD and about 45 minutes 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.
There is one caveat though. As you tape down the copper insulation tape, be sure not to tape over any grounding points. I did copper taped my SCHIIT MANI Phono Stage. I was not facing any issues with that component. I only went ahead as I 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. On my DIY GhentAudio case that housed the ICEpower modules, there were a few grounding points. I left those exposed.