The reason for the noise when listening to speech or music with headphones is not always obvious. It can occur in the signal source, in the amplifier path, and even in the headphones themselves. How noise can be eliminated depends on where it originates.
Instructions
Step 1
If you are listening to AM radio broadcasts with headphones, the noise cannot be completely eliminated. Try, however, to decrease the intensity. To do this, use a more sensitive receiver or connect to the existing better antenna. The automatic gain control (AGC) system will reduce the gain of the RF path and the signal-to-noise ratio will change in favor of the signal.
Step 2
If noise in the headphones occurs when receiving a FM signal, it may also be due to inadequate level. Some receivers use a headphone cord as an antenna. That's exactly how phones are. Use headphones with a longer cord, either extend it if you have soldering skills, or simply unroll it if it is folded.
Step 3
Wheezing noise can occur in the amplifier path when it is overloaded. Decrease the signal level at the input of the amplifier, and on the amplifier itself, use the volume control to increase the gain. The sound volume will not change and the wheezing will disappear.
Step 4
If the signal level at the input of the amplifier is insufficient, its gain must be increased excessively. Together with the useful signal, the noises of the cascades located before the volume control begin to amplify. In contrast to the previous situation, there is no wheezing in the headphones, but hiss. To eliminate this phenomenon, reduce the gain with the volume knob, and increase the signal level at the amplifier input.
Step 5
Noise in the form of an alternating current background occurs in two cases. The first of these is poor filtering of the supply voltage to the amplifier. To eliminate such noise, increase the capacity of the filtering capacitors of the power supply, use a more advanced stabilizer in it. Another cause of hum is noise on the cable connecting the amplifier input to the signal source. Replace this cable with a shielded cable.
Step 6
Ringing noise occurs in the headphones when the membrane strikes the case. The reason for this situation can only be an overload of the emitter. Decrease the volume and the ringing will disappear. At the same time, the danger to which the headphones expose the user's hearing will decrease, or even disappear altogether.
