Audio converter and noise?

Question

Iron

The situation is this: in order to galvanically decouple the computer and acoustics, I purchased an SPDIF-RCA audio converter (the computer is connected to it with an optical patch cord). It turned out to untie, the 50Hz background disappeared, but a new nuisance appeared. It turns out that this audio converter, in the absence of a signal at the input (the computer is turned off or just the patch cord is not connected to the input), apparently for reasons of energy saving, something turns it off and as a result, noise appears in the speakers at the output. The noise is more like "white", and not like 50Hz pickups.
I ordered this converter .
Actually, the question(s). How to get rid of this noise? What to do with the converter? Can you recommend using some other converter? Which?

Answer 1

And unless the given problem with the converter, instead of with the amplifier? Try to pull out the tulips with a working converter, if noise appears, then it's still an amplifier. When the signal is lost, the AGC raises the level and noises are heard. But this disease is only for purely Chinese products, because. in serious devices, this was cured a long time ago ...