Problem with DAC Audiomeca Ambrosia

Good afternoon.
There is a DAC Audiomeca Ambrosia.
The problem is as follows: when connecting the RCD (Rega Jupiter) via any of the 2 inputs of the Coaxial S/PDIF, and selecting the corresponding input by the input selector, the LOCK indicator, notifying, as far as I understand, about the normal connection, does not light up. At the same time, a continuous crackling is heard. Both devices are turned on. There is no way to check the operability using other types of inputs (BNC).

If there are owners of this DAC, tell me which cable (coaxial), how many ohms you use. I met information, that its coaxial input is designed for 100 ohms. Is correct?

I would be grateful for any help.