Folks seem to forget one very important factor when choosing an amp, tube or ss, and that is the quality and ability of the transformer. This, IMO, has more to do with the drive capability than just about anything else. The amount of watts/ch is secondary to this aspect. This is the reason that a lot of well built lower powered tube amps with great transformers can sound as loud, or louder, than a much higher output ss device with a wimpy transformer, as an example.
Moving away from inefficient/low impedance speaker in order to move to a Tube Amp
I think this is talked about more on the amplifier side...tubes to solid state or vice versa. But as we all know, going with a tube amp requires some effort in choosing the proper speaker. I have Harbeth C7's, which are a very nice speaker....but I'm not willing to spend the money on a high quality 100 watt tube amp. For those that have been in this scenario, please share some additional steps from your journey. Example 1: You had speaker A, but surprisingly found it worked fine with tubes...Example 2: You had speaker A, but it did not sing with tubes, so you found speaker B, and paired it with Tube amp C..... Cheers -Don