I agree with much of the above, a DHT SET amp is a unique beast that's nearly impossible to replicate with SS electronics. I've seen good suggestions including SS amps designed to produce a "tube" sound, and even OTL. Let me recommend another way to go (not to get a true SET sound, but to definitely get the magic of tubes but with SS power), and that's a hybrid amp. No, NOT what many call a hybrid these days, which is a SS amp with a tubed input stage. I'm talking about a true tube amp, with a Futterman based OTL tube circuitry, but with a MOSFET output stage. Of course I'm talking about Moscode. I own a George Kaye modified Moscode 401 HR and while the sound is not SET (what else is?), it is very much a modern tube amp, but one that outputs over 200 wpc (and one that's surprisingly easy to tailor to your tastes with a little tube rolling). Several publications reviewed this amp, but the 6moons article does a pretty thorough job describing it.