No one mentioned the fact that power tubes (power amp) need replacing more often than signal tubes (pre-amp)at a much higher cost; 5 to 10 times higher or in some cases higher yet. Pre-amp tubes usually will last 3 -5 years with normal used while power tubes will go 1-3 years max. So maintenance cost with tubed power amps can become quite substantial. However they are beautiful to look at and listen too and add an air of romance to the music that solid state just can not match.
Chuck
Chuck