If the amplifier is genuinely running in class A (which I doubt) it should not generate any RFI.
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It is difficult to tell from the video if the interference varies in unison with the audio, but the Spectrum Analyser plots suggest a single switching frequency and harmonics, which to me suggests a power supply issue.
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I believe the noise is most likely being introduced from the USB port, or whatever is powering the amplifier, so personally I would concentrate on that rather than the amplifier, as I think you have tried just about every usual technique of RFI suppression on the PCB itself.
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I'd suggest trying a screened PSU cable, with good decoupling of the supply cores at each end, and a decent bond to ground at the PC end.
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Regards,
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Martin
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On Sun, Feb 23, 2025 at 05:17 PM, enriqueeeeee2001 wrote:
Trust speakers, it has a class A amplifier and radiates a lot s of RFI
