Okay. If you could find a 1/8 adapter for the male 1/4 plug perhaps you can plug directly into a MP3 player or telephone and take a listen. If you then have no static when bypassing then it might be the amp.
I have heard that just a handful of Sennheiser HD700s or HD800s headphones per thousand made need to go in for repair, outside of the cords, so I hope you do not have that issue, even if your headphones are in the warranty period. Are you using the stock cords?
Since the issue was happening on my HD700s I switched to my HE-500s and started noticing the same issue on those as well. I requested a RMA from NCIX (where I bought my HD700s) and also sent an email to Jason from Schiit to see if he knows anything about this issue.
I will also pick up a 1/4 to 1/8 adapter for further testing on my MP3 player...hopefully some stores will bee open on Christmas =/