Low Watt Solid State Amp

I too have an appreciation for low watt solid state amps and I use an Arcam CX Alpha 5 integrated amp, which is rated at 45 watts rms. The built in preamp of this unit is exceptionally clean and simple so that it impedes as little as possible the output and runs very cool. However, regardless of its low wattage, as in the Dynaco, (which are amazing as you say) the Arcam easily drives fairly heavy loads, as in my Def Techs. The earlier Arcams (say 1988 through the mid 2000s) were still being made in the UK, and I'm not sure about present models. I think that these are fairly accessible on Ebay, etc. 

Try an SAE Mark 31B for about $100. I think you'll have a lot of fun.

I run a pair of Monarchy's. I have never checked the temp,but they do get warm to the touch.

As another in the "I am a tube guy" camp here’s a few that haven’t been mentioned. The Akitika GT-101 LM3886 Gainclone kit amplifier rated a 50wpc @ 8 ohms is a bang for the buck if you add a couple hundred dollars to upgrade most parts as you build. Another fun one is a vintage circa 1974 Marantz 1070 integrated which has pre/amp in & out. Very conservatively rated at 35wpc since most are actually in the 40-50wpc range @ 8 ohms. If you bypass the 1070’s preamp with your own preamplifier just using the Mosfet amp section your in for a treat. It has a warm & forward sound signature & when mated with a tubed front end puts a smile on your face. I ended up selling the 1070, but it left enough of an impression that I wanted to hear it’s smaller sibling the 1040 rated at 20 wpc. The 1040 unlike the 1070 doesn’t play well with speakers as low as 84dB, but at 86dB & up it can shake a large room. It doesn’t have pre/amp in or outs so you need to open the volume pot if you want to use your own preamp. Far less parts then in the 1070 and less is definitely more as it’s just a really fun mood ring... Oops make that mood amp.