A while ago I wanted to improve my audio setup in my office. I ordered some bookshelf speakers and hooked them up to an old receiver I had sitting around doing nothing. To help improve the setup further I decided to use a USB-C to optical adapter so that I could feed pure digital into my receiver. The receiver has a better DAC than my Mac and it reduced the noise a bit as well. Once I did this however I noticed that sound effects from the system and the first little bit of music would not play. This was because macOS does it’s best to save power and will power off, or whatever it is doing, the sound card. In turn the receiver would see no signal and sort of forget what sound format it was receiving. When audio started to play then it would determine what type of audio it was getting and then output the audio. Of course, this takes enough time that most system sounds won’t play and instead I’d got a small pop sound in the speakers as the receiver “came online”.
To combat this I found this little helper – https://github.com/mttrb/antipopd. This app will send what amounts to a null (in the background it is the say utility saying “space”). This keeps the audio chain alive and prevents any pops or delays in audio output. I highly recommend it.