30 to 50 watts seems to be all I desire

I use a Keces E40.  Measured 34 watts/61 watts at 8/4 ohms when it reaches 0.7% distortion.  Company claims up to 15 amps/channel max output.

It's a little powerhouse that's on the warmer and smoother side but retains lots detail with really good separation and stage depth.  I also own a Hegel which I may sell as the Keces is really doing it for me.

Preferred it over other amps I tried from Emotiva, Musical Fidelity M2si and Rega Brio, among others. The Emotiva had a bit more extended highs but flabbier bass and sounded 2D to me.  The M2si was gritty to me, lacked refinement and sounded more like a PA amp.   The Brio is nice enough, but more expensive and I still like the Keces better.

So, lower power but still robust for an affordable price.  IMO.

Mark Schneider, owner of Linear Tube Audio uses a single ZOTL40 to power his Maggie’s. I’ve heard them in his home and the synergy is spectacular.

I drive really low efficiency speakers (86 dB electrostatics) with 45 watts (big Class A watts, but only a max of 45 of them) with no need for any more.

Had big amps in the past, Perreaux, Krell, etc. but now go tubing with a 30 Watt Triode/60 Ultra-linear Cary piece. Can't see myself ever going back unless I absolutely fall in love (again) with a power hungry speaker. System symmetry is paramount. Have to pay close attention to what components get mated togther. I'm in the pocket right now with my modest setup

In my experience a 45-50W amp + 90-92dB speakers is a sweet spot if you are looking for a seriously good sound for sane money.

My current LTA Z40 is about 48W at 6 Ohm, its' volume control goes from 0 to100, and I mostly listen at 4 to 6. The speakers are 91dB.

I could probably use a 10W amp, but a bit of a headroom never goes amiss. And the tubes are never stretched.