The preamp is the sound source. In the early days, it was a CD player, or a Blu-ray CD player, etc., usually like Onkyo, Yamaha, etc.

The main function is to convert the content of the music carrier into an analog signal.

Currently, what is often said on the PC side is to download audio files with lossless or even Dolby sound effects, and then convert the signals through professional external sound cards or decoders. This is the preamplifier on the PC side.

Then there is the post-stage equipment, that is, the headphone amplifier (power amplifier), which will perform signal amplification gain and other processing on the analog signal.

Finally, it is handed over to the playback device, which is the headset.