I read the two responses to this query with flat-out astonishment.
Either the two respondents heard defective amps or, with respect, they need their ears syringed. Or, just maybe, they are so seduced by modern clinical digital equipment that they simply fail to appreciate what a delight a valve-tempered sound can be (but that would not explain why Shafin has a Cayin valve amp).
Anyway, my opinion is that the Wi-Tube is excellent and, at the price for which it is now selling, something of a bargain. It has plenty of slam and extended bass and an open, atmospheric and airy soundstage: a real treat compared to the much more (on paper) powerful transistor amp it replaced. I use mine through Dynaudio Audience 52s, which are 4ohm rated and reputedly a difficult speaker to drive – even though the Wi-Tube is only 28 watts max it’s no problem to go loud in a large Victorian flat living room with 4 m ceilings. The stock Chinese valves need a substantial time to burn in (probably weeks), but I have already sent off for some NOS 1970s Russian valves (about £2 each) which I hope will be even better when burnt in.
I hope that offers some balance to the other opinions, which I feel is required.