Amplifier starts playing digital sound from REALTEK Audio Digital Output after a delay

Question

I have an issue with playback through an amplifier - RCA digital out from a PC to digital in on an amp. It works but it behaves like this:

If there is a 3 seconds sound source from PC, the amp wakes up (you can hear it) and then you can hear the playback right from the amp. The sound is good but the big 3 second delay is not good.

Is it how the amp works or how Realtek digital outputs are handled with the source? How can I fix it?

Answer 1

From what I can see, the two main reasons appear to be:

• S/PDIF supports two sampling frequencies, 44.1kHz and 48kHz. The receiving device thus needs to detect the incoming frequency each time the transmission starts. It becomes worse if jitter is present due to either side not having a stable clock reference.
  • You can speed up this process by setting the same frequency to transmit/expect at both ends.
• The output device may be doing some nontrivial signal processing by default which, naturally, takes time. But if this is the case, it should be playing normally but later rather than skipping the first few seconds as you seem to report it does.