For some time now I have noticed that some noise in the speaker ZX Spectrum clone "Byte-48", which is also the output MIC. They appear randomly, sometimes almost absent and time intensive. I made a few modifications in the truth but I checked the power meter and there are no faults - everything is done carefully. Moreover, these disturbances were already before reworking power. Reworked a bit RGB interface by changing the function of a pin - sound output is 5V you need to switch TV in RGB mode:
and reworked power connector using an adapter which I did immediately cross:
"Byte" is working normally but the interference bug me. I did it to a file Cracks.zip (MP3) - the best headphones to listen to the audio program. What could be causing this? At first I suspected power but the same thing happens on the original as well as other AT.