back on topic, this tubeamp does not look like it's build like it should. I love tubeamps, even with the harmonic distortion and did check many inside and outside and know how they work. But this looks like overpriced cheap chinese crap. I've actually seen better chinese builds selling for a few hundreds. And a good tube amp needs to be heavy, that means that the transformers are spec'ed like it should (or even more than needed). A light tube amp should ring an alarm, it means the output transformers are to small to do what is needed.
If you want to test real good tube amps, test Prima Luna devices, or those from Manley Labs or Line Magnetic. They are among the better examples of modern tube amps today, not those of Bob Carver. But you know in advance that they won't sound like you mostly like down here, harmonic distortion will always be much higher than modern style amps, but that is just what we tube amp lovers love when it's done right.