That's my point exactly, everything here is done badly but the Alo Studio Six is billed as the best there is by shills/reviewers. It must be awesome as it has 4 TRS sockets which all will drive your headphones equally badly and some tubes that can be rolled endlessly. What more could anybody want?
Well the PSU is fubar and so it the heater supply. I'm all for running the tubes off DC but any good designer would use a custom transformer which has enough headroom to regulate said DC. Pehaps Marc is right and the high ripple was part of the design... Then we have the 47uf cap after the rectifier which guarantees that the owners of this pile of fail will be rolling rectifiers like crazy to try and find one that tolerates being run on the limit. Not quite as bad as the Woo crap but that also takes a special level of skill.
As for the actual amp section, I agree with Doug that there isn't a chance in hell this was designed to drive headphones. Also any tube amp will also only be as good as the transformers it uses so the best they could do is the cheapest Edcor? This is a 4200$ amp not some 500$ Chinese ebay job.