I just saw on another forum that GNSC has closed. If you go to their website, Steve lists three recommended dealers for servicing any of the products that they've upgraded.
Too bad. I have a modded Opus 21 from GNSC and its one of my all-time favorite pieces of gear. Plus they were always top-shelf to deal with. Hopefully, those guys will land on their feet.
You must have a verified phone number and physical address in order to post in the Audiogon Forums. Please return to Audiogon.com and complete this step. If you have any questions please contact Support.