The iPurifier SPDIF does not perform any conversion.
However, without input it will normally stay locked on the last sample rate received, if there was no input at all ever it will “hunt” for a signal to lock on.
If there are noises during normal playback with a constant sample rate and during the same track, the problem may be external transients.
Due to the galvanic isolation, the output from the SPDIF iPurifier floats without reference to earth. The DAC or one item in the rest of the system the DAC is attached to should have an earth connection. If this does not exist a supplementary earth strictly for audio purposes should be added – consider the GroundHog+.
If the noises only happen during sample rate changes or track changes them the problem is that the attached DAC does not mute correctly and the short time in which the SPDIF iPurifier re-locks and re-buffers the SPDIF signal suffice to cause noise.
In this case we can try to evaluate the interactions further, but we must know the details of the DAC.
Open a ticket and provide the information.
