I've noticed 60 Hz mechanical hum emanating from the GG DAC, presumably from the transformers inside this wonderful DAC. Have GG DAC owners experienced this? It's not loud enough to be intrusive but notieable. Also, when the volume is crank up, there is the same hum through the speakers. Again, not loud enough to be intrusive but noticeable during quiet passages of music. Any way to get rid of the hum?