I've only heard the Spectron once at RMAF. It sounded nothing like a tube amp. I don't remember if they were using a tube pre or not. It was not my cup of tea. Maybe in a different setting it would shine I don't know. The best switching amp I've heard was the Jeff Rowland 301. Though I would not say it sounded like a tube amp it was quite natural sounding. It is also good at driving tough loads which most tube amps can't do.
