NAT Audio will take a part on American Rocky Mountain Audio Fest at the Denver Marriott Tech Center Hotel from 11.-13. October 2013.
WORLD FIRST VACUUM BASED INVERSE RIAA NETWORK-Signature Phono
WORLD FIRST METAL-CERAMIC MILITARY TRIODE TYPE ZERO FEEDBACK SINGLE ENDED (100W of power)-Microwave
See about this at http://audiofest.net/new/americas-audio-show/2013-products/?keyword=N