Wow, what a thread! OP, there is a ton of misinformation here. Read some articles by experts to get an answer to your question. I'm not an expert but I do know that with a tube amp, it isn't about the wattage, it's about the output transformers, and their bandwidth and power output.
But, the real question you are asking is about those particular speakers with tube amps. This is the right answer!
As it happens, I have a Primaluna HP Integrated tube amp that I love, and think sounds fantastic with every speaker I've heard with it. It puts out close to 100 watts with KT150 tubes.
However, a local friend invited me over to listen to his AR9s. He has them connected to vintage NAD mono blocks and they sound great in his room! But, he is thinking about updating his amps to tubes. His dealer brought over a Primaluna HP Integrated to listen with his speakers.
It was not a good match. I don't know the technical reason - it was definitely plenty of output power. But the bass was kind of flabby and weak, and overall the speakers sounded flat and uninviting. I was shocked. This amp has never sounded so poorly with any speakers I've heard.
The dealer wanted to bring something else along to listen to. So, he connected an Anthem STR 200 wpc integrated, with room correction, and the speakers sounded much better. Tight bass, smooth overall sound, and really good overall.
Hooking the NADs back in the mix (I think they are 200 wpc) and the sound was very similar to the Anthem. The speakers sound fantastic. Deep, taut bass, wonderful midrange, just fantastic. I was shocked that the SS both beat the PL. The NAD and Anthem had very similar sound signatures, and worked very well with these speakers. He decided to keep the NADs and save his $4500. Instead he had the NADs refreshed with new caps, etc.
Point is, as pointed out by @yogiboy these speakers aren't a good match for tubes. At least not Primaluna tubes, which I consider to be top notch equipment.
But, the real question you are asking is about those particular speakers with tube amps. This is the right answer!
05-07-2019 9:17amyogiboy2,778 postsYou are better off using that speaker with solid state. It is not an easy speaker to use with tubes!
http://www.thevintageknob.org/acoustic_research-AR9.html
As it happens, I have a Primaluna HP Integrated tube amp that I love, and think sounds fantastic with every speaker I've heard with it. It puts out close to 100 watts with KT150 tubes.
However, a local friend invited me over to listen to his AR9s. He has them connected to vintage NAD mono blocks and they sound great in his room! But, he is thinking about updating his amps to tubes. His dealer brought over a Primaluna HP Integrated to listen with his speakers.
It was not a good match. I don't know the technical reason - it was definitely plenty of output power. But the bass was kind of flabby and weak, and overall the speakers sounded flat and uninviting. I was shocked. This amp has never sounded so poorly with any speakers I've heard.
The dealer wanted to bring something else along to listen to. So, he connected an Anthem STR 200 wpc integrated, with room correction, and the speakers sounded much better. Tight bass, smooth overall sound, and really good overall.
Hooking the NADs back in the mix (I think they are 200 wpc) and the sound was very similar to the Anthem. The speakers sound fantastic. Deep, taut bass, wonderful midrange, just fantastic. I was shocked that the SS both beat the PL. The NAD and Anthem had very similar sound signatures, and worked very well with these speakers. He decided to keep the NADs and save his $4500. Instead he had the NADs refreshed with new caps, etc.
Point is, as pointed out by @yogiboy these speakers aren't a good match for tubes. At least not Primaluna tubes, which I consider to be top notch equipment.