When were the best tube amps made?

@mulveling @sns  Yes, I chose an AR SP-14 over the 9. I did not like the 9.  The 14 had some superior sound advantages.  The SP-10 was my favorite and the SP-8 my second favorite of the era.  They had big, bold, full bodied sound (like a Fisher 200? preamp that I briefly owned).  Comparable to a McIntosh MC30 full range.  

My neighbor has an AR LS-28.  It sounded thin and blah until he installed 6H6/6N6 tubes for the 6H30s.  Wow, fantastic improvement.  I would own that pre-amp if I didn't have my own excellent pre-amps (multiple systems).  

As to great sounding, powerful modern tube amps that are still reasonably priced is the EAR 890.  I just purchased another one inexpensively.  Paravacini knew transformers and circuit design, regardless that they are not considered state of the art and used ordinary audio parts, no special cables, fuses, tubes or footers (I use them all on the 890 except the tubes remain the same).  Zesto is copying his designs and I have not auditioned them to compare.  That's flattery and could be a trend, using common tubes in non-ultralinear designs.  I considered the VAC iq200 but the EAR is just better sounding and cheaper.  

@alexberger Thank you for your list. Matching the amp to the speaker is critical, similar to a cartridge to an arm. However, there are many choices of amps for most speakers. I also have an upgraded Dynaco ST70 in my living room system. It is not ultralinear any longer but voltage regulated using different taps on the transformer as well as the standard upgrades to power cap (huge), ss rectifier (kept the tube for slow turn on) RCA plugs and speaker terminals, etc), . It has superb bass and is extremely musical sounding lacking only the resolution of the EAR 890 I use in the main system. Those 35 watts work great on a Legacy Signature III with 6-10" woofers. It’s a little underpowered for my Focus with 6-12" woofers and much lower bass impedance.

The science is settled. 

Really great thread with lots of thoughtful responses. Thanks!

To me, the answer becomes obvious when you substitute “motorcycles” or “cars” for tube amps.  Clearly the best are being made today. But it doesn’t mean that all cars today are “better” than all cars made in 1960. It would also be logical to suggest the best amps from 1960 (and all amps were tube then) will outperform many of the tube amps made today.  This is especially apparent when based on subjective levels of performance or aesthetics. 
 

I’m interested also in the comparison to the recording side. Are all recordings made today better than all recordings made in 1960?  No, but the best recordings are being made today.