More than likely its the headphones.
Or the source.
Or the amp.
There are lots of variables here, could you tell us more?
And no, you should never solder mains cables.
BTW, did you try to run a (device) set up for 220v on 110v? Dont do that. (standard head-four-chan caveat, this excludes certain older stax devices that were designed to run on either voltage without conversion)
Quote:
Originally Posted by
mralexosborn 
I receiver my Stax today and an adapter. The 'phone were very sibilant. I thought maybe it was the Europe to US adapter that it was plugged into. I remove the adapter and the European termination just falls off with NO force applied.
Question is, can I just find an old plug, snip off the plug part, and solder it onto the wires?
Thanks.