Clay,
I think that I might actually have just about the only 100V HX100 in existence, here in Japan!
Over the past few years I have slowly been adding EAR components to my setup, first the HP4 headphone amp and then the 88PB phono stage. I recently bid farewell to my trusty L300 which had been at the centre of my system for 17 years. In its place is now a Benchmark LA4 which really lets the 88PB shine through - with the L300 I was only getting a hint of what the phono stage is capable of.
So the 509s would finish things off nicely, I think. Although they are valve/tube amps, they don’t have the typical “tubey”
sound - people say that they sound more like solid state. They have bags of power too (100W) and they are said to be capable of driving just about any speaker.
That’s my reasoning, anyway…