Static noise help please

Eddy - haven't experienced what I consider "static" from tubes but definitely a few random pops soon after start up that eventually turned into tube failure... an EL34 power tube.  Static to me is a more prolonged sound, sort of a rapid, lower volume crackling.  I'm wondering if it could be due to a dirty or loose connection that got "fixed" when you changed out gear.  Have you returned the ARC gear to service and is the static noise still gone?  Good luck.  

Hello again Eddy.  I use a Macbook Air into a Gungnir via USB but it isn't connected directly.  In between there is a V-Link USB/SPDIF converter.  The Gungnir does not have a USB input.  No noise.  Things are very quiet.  You might try calling or emailing Schiit to see what they think the source of the noise might be.  Or, maybe consider an Audioquest Jitterbug.  They are supposed to clean up the USB/audio signal from a computer...only $50. The other thing i did on my system was get a split USB cable...one leg for signal one leg for power.  Both legs have A type USB connectors and are joined at a single common B connector that goes into the V-Link (or, in your case would go into the Modi, I'm guessing).  There is a V-Link on A'gon for $110 if you want to try that.    

Spencer - Wasn't trying to generalize about all Gungnirs - but can see how what I wrote could be understood that way.  Had I written "The Gungnir in MY system does not have a USB input.", things would definitely have been clearer.   Good clarification.  

Eddie - I can't compare that galvanic isolator to the JitterBug.  Sorry.  The JitterBug is only $50 or so from MusicDirect and they do have a (60 day?) return policy, so you could try it and send it back if it did not fix your problem.  

Schiit also makes something called the "Wyrd USB Decrapifier".  $110 from Amazon.  See link here:

http://www.amazon.com/Schiit-SCH-16-Wyrd-USB-Decrapifier/dp/B00LFVMC9U

I take it you have tried other USB ports on your MAC as well as moving the Modi from near the monitor, etc. (as suggested on that Computer Audiophile thread).

Eddie - I'm guessing you will be wanting to try a "double-headed" USB cable that separates signal from power.  The one from iFi (Gemini Dual Headed USB cable $265 for 1.5M on Amazon) is kind of pricey, I think.  There are some lower cost options.  

I bought one from a seller on Ebay [Doukmall (China)].  At the time it was only $59.  I use it with an inexpensive Enercell 5V AC/USB converter.  No noise and things sound great.

Here's a link to the latest from Doukmall.
http://www.ebay.com/itm/SLK-Audio-OCC-Copper-USB-Audio-Cable-signal-wire-Hifi-Decode-Line-50CM-/252022624130?hash=item3aadb80f82

Looks like the price has gone up but still cheaper than the iFi.  If you are skeptical about the quality of the power from the Enercell you can try the Wyrd from Schiit.

Here on A'gon there is a seller robpriore who sometimes lists a "USB Disruptor".  It is also a double-headed USB cable but he sells it with a power supply and the price was previously only $74 or so.  I don't see it currently listed in the usual Digital/DA Converters category so you might want to drop him a note and inquire about current availability.  

Here's a link to a discussion about it:

https://forum.audiogon.com/discussions/audio-grade-usb-cables/post?highlight=usb%2Bdisrupter&pos...

Hope this is of use.  Good luck.

Eddie - do you already have that Sony portable power supply?  I'm just wondering how long it will last in an audio application.   You could also just try using a typical wall plug/USB converter like for charging an iPone...or even a powered USB hub, for that matter.  

Whatever you decide, good luck cleaning up that static.

Eddie - glad to read splitting the USB cable got rid of the static.  That 5V Enercell on Ebay is the one I'm using.  It was originally recommended by Williewonka (a member of A'gon).  If you feel like it, I'd be very interested in a step by step procedure for how to build a 2 headed USB cable.    

Eddy - Thank You. I think I get it. I did not know which of the wires in an intact USB cable were carrying signal vs power. Sounds like red & black carry power so those (red to red & black to black) need to be soldered together to join the leg from the 5V power source to the USB cable running from the MAC to the DAC.