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! 

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,
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.
Is the static present at very low volume?  Or only after a certain volume level is reached?
There is a similar discussion at the Computer Audiophile site/forum you may want to review. I would start with the USB Hub as the potential problem. It seems interesting the static occurred after getting the upgrade performed and not before. The Hub at the computer or Ayre could be the problem and least expensive to troubleshoot. Good luck resolving the issues.
Found the problem! I replaced my $$$ Ridge Street Audio Poiema USB cable with an off-the-shelf USB cable and all static is gone! I didn't think a USB cable could go bad. And I really liked that cable! I guess Ridge Street Audio has gone out of business, because I can't find a website for them.

So, next I have to decided on a new USB cable. Any suggestions?

Thanks for everyone's input. Much appreciated!

Thats great! I had the original Ayre QB9 (non-DSD)  and the Ridge Street Audio Poiema USB cable, along with several others. I never liked the cable compared to the Transparent Performance USB and a couple of others I tried. Did enjoy the Hi Rez Disk Ridge Street sent with the cable though. 

Have demoed numerous USB cables and in my system the Audioqest Carbon has sounded the best. That included a comparison to the much more expensive Diamond....go figure. also used the Wireworld Starlight 7, Total DAC and others. they do sound different to my ears....enjoy the search.

Take a look at this when you get a chance. There seems to be agreement that an effective USB cable must have an impedance of 90 Ohms. They indicate comments made by Gordon Rankin who founded Wavelength Audio and help design the Ayre QB9.
It could be that the $$$ Usb cable could be very sensitive and is transmitting the noise generated by the mac/usb port that would be attenuated by an inexpensive cable.  Computers and USB ports are very noisy devices. 
Nice.  I use a transparent usb for about $90.  Pretty good, didn't break the bank.

I also have the Ayre QB9 DSD DAC with a Mac mini as a server. The Audioquest diamond USB cable was a HUGE improvement over several other USB cables I tried. Cardas Transparent Nordost. Night and day difference. In fact I actually took a demo QB 9 back to the dealer when I first heard it with the Transparent cable. 
Bought a Benchmark DAC 2 where I discovered the AQ cable. I realized the USB  cable had a huge impact when we tried the AQ Diamond in a friends CH PRECISION DAC. So give the AQ
diamond a try if you want to hear how good that QB 9 can be! No affiliation with AQ btw.