I've had an Xd 2.1 system for 2+ years. Initially, I had a ground loop buzz, but NHT sent me a free set of RCA to balanced interconnects that solved the issue. I am now running fully balanced from my Transporter/pre into the xDA, and love the results.
In addition to NHT continuing service, you could contact www.audioconsultingservices.com, which are ex-NHT engineers who worked on the original Xd design. They do mods as well as custom filters. That gives 2 options should anything go wrong.
With prices for remaining inventory 1/2 of new, this is an absolute killer deal. If you want great sound quality that will get you off of upgrade-itis, xD's are an excellent choice.
In addition to NHT continuing service, you could contact www.audioconsultingservices.com, which are ex-NHT engineers who worked on the original Xd design. They do mods as well as custom filters. That gives 2 options should anything go wrong.
With prices for remaining inventory 1/2 of new, this is an absolute killer deal. If you want great sound quality that will get you off of upgrade-itis, xD's are an excellent choice.