I can't answer your question as I don't own the HD800, but there's more than just the same chip used for the filter programming at play. The WTA filter is different between the Mojo and the Hugo(1) and the Hugo(2). The output stage is different between them and Rob tuned the Mojo warmer for OTG listening. You made a general statement that the Mojo is weaker than the Hugo(1) and it simply isn't. Maybe if you described in detail what you mean by 'pitiful' then it would help to understand your comment better.
Lot's of people enjoy the HD800... I hate it every time I listen to it and would never try to match the rest of my gear for one headphone. YMMV. The 300 Ohm HD800 is actually a very easy electrical load for the Mojo and people constantly think that the higher the impedance then the harder it is to drive but it just isn't always the case. You aren't the first to mention the HD800 sounds bad with Chord gear and I don't doubt your impressions, but power isn't the reason. One sample won't be the end-all-be-all of how a device performs with full sized headphones in general. All my full sized headphones play very well with the Mojo, including the Utopia which has an impedance of over 300 Ohms at 50-60Hz. Again, power doesn't always equal quality, but quality power matters.
I didn't make a generalisation, I surmised that it could of been due to more power on hugo, surmise basically means to think something which may or may not be true. I have no idea whether mojo and hugo have he same power output, but you nit picked and took one sentence out of my entire post to quote.
Within my post, it's in context, and I only meant that surmising the situation, maybe it was due to more output power.
My "pitiful" comment means what it means, it's like the headphones are sounding atleast 50% worse than what it sounds like on TT2 and H2, it's veiled and muffled on mojo. Thats using a supplied adapter from chord, my other headphones all use 3.5mm jacks.
On H2 and TT2 the HD800S sound great. I know "folk" don't like the HD800 or 800S, but it would be obtuse of anyone to solely buy what 1 or 2 people say, as everyones hearing is different and although I suffer from tinnitus, I have bloody good hearing and I'm positive that I hear better than say for example, those in their 50's 60s, 70's.
I'm not saying that the HD800S sound bad on Chord gear, I'm just saying it sounds bad on mojo, which to be fair, was probably designed with iem's and smaller headphones in mind, although Chord do say mojo is good for big headphones also.
From my point of view and I've only got 6 pairs of headphones, but all 5 lower than 100ohm sound great, they work perfect, but the HD's sound as though your listening to them from behind a lump of sound proofing foam, and thats saying something.
I have no problems with my hd's not sounding even half decent on mojo, because I didn't buy it with the intention of using it with headphones, only iem's and thats probably what chord envisaged with mojo.
If I was surmising yet again, I would say that they maybe made hugo with iem's and big headphones in mind. Again, I surmised, which only means I think it may be this way, but I have no proof to say for sure.
Truth be told, the HD800S were an impulse purchase, I hated the look of them and bypassed them for ages, but I was speaking to someone who owned a pair and I decided why not. Do I regret my impulse purchase, no, because I could of sent them back for a refund if they sounded schit, but they sounded good, and I don't regret buying them at all.