depends on Ur basis of adjustment
If your case is pending in xyz, you have to get the EAD from xyz. If your case is pending with a service center, then you can get it form the other service center.
Generally, most of the district offices will entertain interim EAD requests if an EAD was pending for more than 90 days. Some issue interim EAD even if EAD application is pending for less than 90 days- like Boston. U have to go to a district office to get an interim EAD