Let's not forget the SET solid state amps already out there like Sugden's A21a.

It's not that SS sounds bad it just always seems to cost so much more than a SET tube to sound as good. I audition SS amps I like like Technical Brain, Pass Labs, Sugden Master Class, and I see Sticker price of $10k to $70k and I think does it sound better than the SETs I've heard for around $3k and the answer comes back no. So I don't see the point in spending many more times the price. But that is a value judgment more than a quality of sound judgment and each person attaches their own value to such things. But that is now.

I can't see why anyone into SET would dump on Pass or Sugden - anytime a company owner has EARS and knows that SET sounds best and tries to achieve that sound to me is a company to follow.

Of course the only problem with comparing a SS amp that is designed to sound like a SET is that SETS hardly sound like eachother - from brand to brand or tube type to tube type - or from the same tube type but different tube manufacturer.

The key issue is which amp sounds best with a specific set of speakers and source. I have preferred the Sugden A21a over many many more expensive tube amplifiers and virtually all SS high feedback amplifiers. Strangely some class D amps which claim zero feedback have sounded surprisingly off - after auditioning the Bel Canto many years ago and recently here in Hong Kong the on paper blather should make them sound good. They just don't. Really something strangely off about them but I can't quite figure out what it is. Maybe if I had them at home for a long period I could get into what it is that's wrong.