Constant noise when recording from a microphone when using an external usb audio card, how to fix it?

Question

USB

Hello, I bought 2 usb audio cards based on the c-media 108 chip
Tried setting them up on both windows (laptop) and linux (laptop), same issues on both machines on both cards. While listening to audio, a strange ringing appears, it can be minimized by sound settings. However, during microphone recording, the ringing is amplified and recorded. I assumed that the problem was with the microphone and did so. Turned on the card with the microphone and headphones turned off, made a recording, no ringing, connected the microphone and headphones, recorded, the ringing appeared, turned off the card, turned it on only with the microphone and recorded the test, there is ringing, turned off the card, turned it on only with headphones, made a recording, ringing is also present. With agc turned off, it drops significantly, but the voice is almost inaudible. During the tests I used different headphones. The tests were carried out in different places in order to avoid the possible influence of any device nearby. Noise appears during any interaction with the means of recording or playback (when the diode blinks). It is weak during playback, very strong during recording, and it is present not only in the recorded file, but it is also heard in the headphones directly during recording. Given the fact that I use different machines, two cards from different suppliers, I doubt that this is some kind of marriage. What can be wrong? Noise recording: two cards from different suppliers, I doubt that this is some kind of marriage. What can be wrong? Noise recording: two cards from different suppliers, I doubt that this is some kind of marriage. What can be wrong? Noise recording: https://drive.google.com/open?id=0B5Nyvy7MOQ8aTXZ0...

Answer 1

They are very low quality. Squeak 1kHz, smooth - electronics fail.
If you want to continue using them, you can remove the squeak with a filter in Audacity, but the voice will also be distorted a little bit.