I have a small USB powered soundbar, but when the soundbar is turned on at above average volume, I get a high pitched screeching sound that varies with the volume. The soundbar is tight against other electrical cords so I figured it might be RFI. I bought ferrite cores but they made no difference. I decided to include a ground isolator in the USB circuit, but was confused by the price difference: they were either $15 or over $30. Since this isn't a HiFi situation, I opted for a cheaper Nobsound USB Isolator, which installed in half a second and completely removed the noise. Remember that the two little switches are set correctly for your situation (which they were when I got them).
ARESGAME AGK850 - 850W Fully Modular 80Plus Gold Certified Power Supply Unit
32 Review
TEAC CD-RW890MK2-B Home Audio CD Recorder With Bluetooth - Black
38 Review
2-In-4 USB 2.0 Switch Box - SGEYR Metal, One-Button Swapping & 2 Pack A To A Cable For Printer/Mouse/Scanner Sharing Between PCs
39 Review
500W PSU With 80 Plus Bronze Certification For Efficient Power Supply
37 Review
Sangean PR-D4W Portable Weather Alert Radio with AM/FM Bandwidth Narrowing and Auto Tracking for Improved Searchability
12 Review
Sony ICFC1TBLACK Alarm Clock Radio
11 Review
Stream Your Favorite Tunes With AUNA KR-200 SI Internet Kitchen Radio - Spotify Support, Remote Control, And More!
15 Review
Radio receiver Max MR-322 anthracite
14 Review