PowerPlay show P20 THD out increased when using an AC plug adaptor to the wall

Hi folks,
I picked up a AC12 power cable to feed my P20 and end up using a cheap US plug to UK plug adaptor to the wall (which I picked up from AliExpress with hot/neutral wire polarity correctly switch from US plug to UK plug into wall socket).

However, this seems to made my whole system plugged into P20 lost dynamic , lost bass, and everything sounded flat and no depth. Then I switched back to my normal power cable (DIY OCC copper thick gauge power cable) with normal UK plug from the wall to PS audio juice bar, then plug AC12 power cable into juice bar then to the P20. Once taken the US-to-UK plug adaptor out, this seems to have brought back everything I’ve lost and perhaps slighly more dynamic & bass maybe due to addition of AC12 power cable into P20.

I was a bit dumbfounded how in the world does an AC plug adaptor like below affect sound quality that much just having it between the wall and AC12 power cable to P20.
Screenshot 2023-05-09 at 1.15.12 AM

Then I went back to check PowerPlay and it seems the cheap AC plug adaptive had caused the P20
P20 THD out % to jump from normal 0.1% to 1.7% (which match THD in %) as the time lined up exactly. I’m even more surprise such AC plug adaptor can have such an effect on P20 THD output.

The only thing I can think of being the reason is perhaps poor or thin wire inside the adaptor, or the 13A standard fuse inside the US-to-UK adaptor contributed to this. What are your thoughts on this?

If I had to guess you should not be using the US version in UK of the P20. or is it just the cable? I thought there was voltage differences or is that EU and not UK.

It’s just the cable, I forgot to mention I"m using 230v version of P20 with UK wall plugs.

I would have no idea why that would do that, wire is wire right… but I am not an EE. I would not use either. I would use a stock cable until you can order the one you want to use. that peak would scare me

It reminds me of the guy who complained to his doctor “it hurts when I do this” . “Well stop doing that then!”. You have all the proof that you need.


Welcome to the Forum @bill-0925!

Did you verify that the the adapter was correctly wired with a meter? I’d do it from one end of the cable to the other including the adapter.

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Yep, the first thing I did before connection was to verify the adapter polarity with a meter to ensure the hot & neutral wires polarity is done correctly from US plug in to UK plug out.

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Well, this chump is stumped.

I had also tried the C13 power cord with an adapter on the C19 and it didn’t sound good. By the time I fitted the correct connector to the cable it was day and night. The adapters are not for hifi.
I ’ ve used Furutech FI 50


I heard the wire inside is thin and poor quality …

I thought that might be the case, but the THD out jump I can’t understand the cause & effect. :confused: