My Cary 805AE can use either the 211 or 845. I prefer the 211 with the speakers I am using. Other than the stock Shuguangs that came with the amp, I have used NOS GE VT4-C that were a nice improvement. I bought a pair of these Natural Sounds about a month ago and am very happy with them. I'd put them up there in the same league with the GE's and at about half the cost. They were real nice right out of the box (surprise) and got better after the usual 10-20+ hours. May even get better yet. Thank you "thetubestore" for offering and excellent choice to what's available out there.