I borrowed a 24-inch iMac over the weekend to kick the tires on for music use. The good news is it's really quick, I like the smaller display, it produces way less heat. All things being equal, I'd love to have one. But there was on big issue.
With the Ethernet connected to the power brick, I got a background modem-like digital whine through my Yamaha HS5's. Like you'll hear from some internal sound chips. RF.
I tried both my Clarett 4Pre Thunderbolt and the Apollo Twin X thunderbolt. Same deal with both. There was no noise from the internal speakers. I tried pulling grounds from everything, and all of this stuff is plugged into an isolation transformer.
Using Ethernet from a dock or adapter caused no noise. I didn't try a USB interface as I sold all of mind, but I may when I return this to the office.
My guess is that the Ethernet next to the power cable is creating RF that's traveling through the power to the Thunderbolt bus.
Has anyone else had the same experience. And if you have an iMac with a USB interface, have you experienced RF noise with the Ethernet attached?