HELP! Static with my Mac Mini / Ayre QB9 system


I just got my Ayre QB9 DSD upgrade back from Ayre. Couldn't wait to put it back in the system with my 2009 Mac Mini.  Huge disappointment! I'm playing iTunes through Amarra and the static is unbearable! I've tried moving power cables and speaker cables around and nothing seems to affect the noise.  I then took a different Mac Mini I use in the office (latest model... without Amarra installed) and just played iTunes direct to the Ayre QB9. The static was nearly completely gone, but there were still intermittent pops and clicks. Any ideas? Any and all suggestions more than welcome! Thanks! 

cdm
What input are you using on the DAC to connect your computer?  What preamp are you using?
One variable at a time; either download Amarra to the 2nd Mac or try the first one with just iTunes.
What type of files did the popping/clicking occur with? Often those sounds are caused between songs when changing to different bit depth/sample rates.
Does the 2nd mac have a different type of power supply? PS makes huge impact on noise from mac with digital music. Cheers,
Spencer
I'm using a USB input. The USB cord is "Ridge Street Audio".

And the file type is aiff. The static is constant, and not at all subtle. And yes, the second mac mini has an internal power supply. It's the latest generation mac. I don't have Amarra on that Mac. It's my office workstation. The static was greatly diminished on the office Mac, but I still got random snapping sounds I've never heard before.

Very frustrating.

I have no preamp. My system amplifier is a Arcam AVR350. I think I've eliminated the Arcam as the cause, since I disconnected the Mac/Ayre QB9 and hooked up an Arcam CD player to the same AVR350 input. The CD player produced no static. So, it's not the amplifier.
Could it possibly be the USB cable? I doubt it, but I'll try A/B-ing that tomorrow.