Analog signal slower than digital signal?

So there are two sound sources, the PC and my Playstation. Depending on what I'm doing, I switch between the two. Both audio signals are regularly passed on to a 5.1 system. Now I have two older loudspeakers that I want to incorporate into the action. I tried using an adapter to convert the digital signal of the source into a digital and an analog signal (chinch). The analog signal went into a classic amplifier and from there into my old boxes. But now the output of the 5.1 system and the old amplifier are very audibly unequal. What should be done to ensure synchronous playback between 5.1 and (digital) and classic amplifier (analog)?

Even if the signals were synchronous (which would be technically extremely complex, because you would have to delay the analog signal), it would not sound good and you would probably have disturbing interference and the spatial impression would be gone.

Exchange the two stereo speakers of the 5.1 system for the old speakers if they sound better. The result can - but does not have to - be better than before.

A / D or D / A conversion never takes place without delay. It can only be done faster with better devices.