I'm a bit confused. IS the V.6 official or not? Can I upgrade my v.4.75 or do I have to get a new unit?

Thanks,
Ken


Meridian 861v6, HD621, G98, Pioneer BD-09, Mark Levinson 436 monoblocks, Aerial Acoustics 20T, CC5, SR3, SW12, Mark Seaton Submersives, QSC 322, Runco Vx22D, Lumagen Radiance XE